pelargonium

Pelargonium occurs in a large number of growth forms, including herbaceous annuals, shrubs, subshrubs, stem succulents and geophytes.{{sfn|Roschenbleck et al|2014}} The erect stems bear five-petaled flowers in umbel-like clusters, which are occasionally branched. Because not all flowers appear simultaneously, but open from the centre outwards, this is a form of inflorescence is referred to as pseudoumbels.

The flower has a single symmetry plane (zygomorphic), which distinguishes it from the Geranium flower, which has radial symmetry (actinomorphic). Thus the lower three (anterior) petals are differentiated from the upper two (posterior) petals. The posterior sepal is fused with the pedicel to form a hypanthium (nectary tube). The nectary tube varies from only a few millimeters, up to several centimeters, and is an important floral characteristic in morphological classification. Stamens vary from 2 to 7, and their number, position relative to staminodes, and curvature are used to identify individual species. There are five stigmata in the style. For the considerable diversity in flower morphology, see figure 1 of Röschenbleck et al. (2014).{{sfn|Roschenbleck et al|2014}}

Leaves are usually alternate, and palmately lobed or pinnate, often on long stalks, and sometimes with light or dark patterns. The leaves of Pelargonium peltatum (Ivy-leaved Geranium), have a thick cuticle better adapting them for drought tolerance.{{cite book|last=Appell|first=Scott D.|title=The Potted Garden: New plants and New approaches for container gardens.|year=2001|isbn=978-1889538228|url=https://books.google.com/books?id=FhGxmyG5HLMC|page={{page needed|date=March 2014}}|publisher=Brooklyn Botanic Garden }}

File:Dillenius Pellargonium.jpg' introduction of the term 'Pelargonium' in Hortus Elthamensis 1732]]

File:P inquinans Dillenius.jpg, (Geranium Afric. arborescens), Hortus Elthamensis]]

Pelargonium is the second largest genus (after Geranium) within the family Geraniaceae, within which it is sister to the remaining genera of the family in its strict sense, Erodium, Geranium, and Monsonia including Sarcocaulon. The Geraniaceae have a number of genetic features unique amongst angiosperms, including highly rearranged plastid genomes differing in gene content, order and expansion of the inverted repeat.{{sfn|Roschenbleck et al|2014}}

The name Pelargonium was first proposed by Dillenius in 1732,{{sfn|Dillenius|1732|loc=[http://bibdigital.rjb.csic.es/ing/Libro.php?Libro=1386&Pagina=280 De Geraniorum Differentiis p. 149]}} who described and illustrated seven species of geraniums from South Africa that are now classified as Pelargonium.{{cite web |last=Handlos |first=Wayne |date=2013 |url=http://www.geraniumsonline.com/18thcentury.htm |title=18th Century: Important People, Dates and Publications in the History of Pelargonium |website=Geraniums Online |publisher=Central Coast Geranium Society |access-date=3 August 2017}}{{sfn|Lis-Balchin|2002|loc=[https://books.google.com/books?id=-bR8GxQ6BU0C&pg=PA52 Diana Miller. The taxonomy of Pelargonium species and cultivars: Classification history p. 52]}} Dillenius, who referred to these seven species with apparent unique characteristics as Geranium Africanum (African Geranium){{sfn|Dillenius|1732|loc=[http://bibdigital.rjb.csic.es/ing/Libro.php?Libro=1386&Pagina=284 Geranium Africanum p. 151]}} suggested "Possent ergo ii, quibus novi generis cupido est, ea, quorum flores inaequales vel et irrregulares sunt, Pelargonia vocare" (Those who wish a new genus can therefore call those, whose flowers are unequal or irregular, ‘Pelargonia’).{{sfn|Boddy|2013|loc=[https://books.google.com/books?id=24eoWcnoyfcC&pg=PR2 Introduction p. 11]}} The name was then formally introduced by Johannes Burman in 1738. However Carl Linnaeus who first formally described these plants in 1753 did not recognise Pelargonium and grouped together in the same genus (Geranium) the three similar genera Erodium, Geranium, and Pelargonium.{{sfn|Linnaeus|1753|loc=[https://www.biodiversitylibrary.org/item/13830#page/118/mode/1up Geranium p. 676]}} Linnaeus' reputation prevented further differentiation for forty years.{{sfn|Lis-Balchin|2002|loc=[https://books.google.com/books?id=-bR8GxQ6BU0C&pg=PA52 Diana Miller. The taxonomy of Pelargonium species and cultivars: Classification history p. 52]}} The eventual distinction between them was made by Charles L’Héritier based on the number of stamens or anthers, seven in the case of Pelargonium. In 1774, P. cordatum, P. crispum, P. quercifolium and P. radula were introduced, followed by P. capitatum in 1790.{{sfn|Taylor|2014|loc=[https://books.google.com/books?id=RWuZBgAAQBAJ&pg=PT207 Pelargonium]}}

Pelargonium is distinguished from the other genera in the family Geraniaceae by the presence of a hypanthium, which consists of an adnate nectar spur with one nectary, as well as a generally zygomorphic floral symmetry.{{sfn|Roschenbleck et al|2014}}

De Candolle first proposed dividing the genus into 12 sections in 1824, based on the diversity of growth forms.{{cite book|author=A. P. de Candolle|year=1824–1873|title=Prodromus systematis naturalis regni vegetabilis sive enumeratio contracta ordinum, generum specierumque plantarum huc usque cognitarum, juxta methodi naturalis normas digesta|chapter-url=https://www.biodiversitylibrary.org/item/7150#page/656/mode/1up|chapter=Geraniaceae: Pelargonium|volume=I|page=649|publisher=Sumptibus Sociorum Treuttel et Würtz|display-authors=etal|author-link=A. P. de Candolle}} (also available online at [http://gallica.bnf.fr/ Gallica]) Traditionally the large number of Pelargonium species have been treated as sixteen sections,{{cite web |last=Handlos |first=Wayne |date=2010 |url=http://www.geraniumsonline.com/pelsections.htm |title=The Sections of Pelargonium |website=Geraniums Online |publisher=Central Coast Geranium Society |access-date=3 August 2017}} based on the classification of Knuth (1912) who described 15 sections,{{cite book |last1=Knuth |first1=R |title=Das Pflanzenreich: regni vegetablilis conspectus|publisher=Engelmann|location=Leipzig|chapter-url=https://www.biodiversitylibrary.org/item/68282#page/322/mode/1up|editor=Adolf Engler|volume=129: Geraniaceae|chapter=5: Pelargonium L'Hér.|page=316|access-date=16 August 2014|year=1912|language=de}} as modified by van der Walt et al. (1977–1997) who added Chorisma, Reniformia and Subsucculentia.

These are as follows;

• section Campylia (Lindley ex Sweet) de Candolle
• section Chorisma (Lindley ex Sweet) de Candolle
• section Ciconium (Sweet) Harvey
• section Cortusina (DC.) Harvey
• section Glaucophyllum Harvey
• section Hoarea (Sweet) de Candolle
• section Isopetalum (Sweet) de Candolle
• section Jenkinsonia (Sweet) de Candolle
• section Ligularia (Sweet) Harvey
• section Myrrhidium de Candolle
• section Otidia (Lindley ex Sweet) de Candolle
• section Pelargonium (Sweet) Harvey
• section Peristera de Candolle
• section Polyactium de Candolle
• section Reniformia (Knuth) Dreyer
• section Subsucculentia J.J.A. van der Walt

All subdivision classifications had depended primarily on morphological differences till the era of phylogenetic analyses (Price and Palmer 1993).[https://www.jstor.org/discover/10.2307/2399852?uid=3739416&uid=2&uid=3737720&uid=4&sid=21104578826543 Robert A. Price and Jeffrey D. Palmer. Phylogenetic Relationships of the Geraniaceae and Geraniales from rbcL Sequence Comparisons. Annals of the Missouri Botanical Garden Vol. 80, No. 3 (1993), pp. 661–671] However phylogenetic analysis shows only three distinct clades, labelled A, B and C. In this analysis not all sections were monophyletic, although some were strongly supported including Chorisma, Myrrhidium and Jenkinsonia, while other sections were more paraphyletic. This in turn has led to a proposal, informal at this stage, of a reformulation of the infrageneric subdivision of Pelargonium.

In the proposed scheme of Weng et al. there would be two subgenera, based on clades A+B, and C respectively and seven sections based on subclades. Subsequent analysis with an expanded taxa set confirmed this infrageneric subdivision into two groups which also correspond to chromosome length (<1.5 μ, 1.5-3.0μ),{{sfn|Roschenbleck et al|2014}} but also two subclades within each major clade, suggesting the presence of four subgenera, these correspond to clades A, B, C1 and C2 of the earlier analysis, A being by far the largest clade with 141 taxa. As before the internal structure of the clades supported monophyly of some sections (Myrrhidium, Chorisma, Reniformia, Pelargonium, Ligularia and Hoarea) but paraphyly in others (Jenkinsonia, Ciconium, Peristera). A distinct clade could be identified within the paraphyletic Polyactium, designated section Magnistipulacea. As a result, Polyactium has been split up to provide this new section, which in itself contains two subsections, Magnistipulacea and Schizopetala, following Knuth's original treatment of Polyactium as having four subsections.{{sfn|Roschenbleck et al|2014}}

File:Pelargonium tetragonum.jpg]]

File:Pelargonium cotyledonis03.jpg]]

File:Pelargonium acetosum (9344387742).jpg]]

File:Pelargonium tricolor hh.jpg]]

Image:Pelargonium crithmifolium3.jpg]]

Thus Röschenbleck et al. (2014) provide a complete revision of the subgeneric classification of Pelargonium based on four subgenera corresponding to their major clades (A, B, C1, C2);

• subgenus Magnipetala Roeschenbl. & F. Albers Type: Pelargonium praemorsum (Andrews) F Dietrich
• subgenus Parvulipetala Roeschenbl. & F. Albers Type: Pelargonium hypoleucum Turczaninow
• subgenus Paucisignata Roeschenbl. & F. Albers Type: Pelargonium zonale (L.) L'Hér. in Aiton
• subgenus Pelargonium L'Hér. Type: Pelargonium cucullatum (L.) Aiton{{sfn|Roschenbleck et al|2014}}

Sixteen sections were then assigned to the new subgenera as follows, although many species remained only assigned to subgenera at this stage

• subgenus Magnipetala 3 sections
• section Chorisma (Lindley ex Sweet) de Candolle – 4 species
• section Jenkinsonia (Sweet) de Candolle – 11 species
• section Myrrhidium de Candolle – 8 species
• subgenus Parvulipetala 3 sections
• section Isopetalum (Sweet) de Candolle – 1 species (Pelargonium cotyledonis (L.) L'Hér.)
• section Peristera de Candolle – 30 species
• section Reniformia (Knuth) Dreyer – 8 species
• subgenus Paucisignata 2 sections
• section Ciconium (Sweet) Harvey – 16 species
• section Subsucculentia J.J.A. van der Walt – 3 species
• subgenus Pelargonium 8 sections
• section Campylia (Lindley ex Sweet) de Candolle – 9 species
• section Cortusina (DC.) Harvey – 7 species
• section Hoarea (Sweet) de Candolle – 72 species
• section Ligularia (Sweet) Harvey – 10 species
• section Magnistipulacea Roeschenbl. & F. Albers Type: Pelargonium schlecteri Knuth – 2 subsections
• subsection Magnistipulacea Roeschenbl. & F. Albers Type: Pelargonium schlecteri Knuth – 2 species (P. schlecteri & P. luridum)
• subsection Schizopetala (Knuth) Roeschenbl. & F. Albers Type: Pelargonium afrum (Eckl. & Zeyh.) Steudel – 3 species (P. afrum, P. bowkeri, P. schizopetalum)
• section Otidia (Lindley ex Sweet) de Candolle – 14 species
• section Pelargonium L'Hér. – 34 species
• section Polyactium de Candolle – 2 subsections
• subsection Caulescentia Knuth – 1 species (Pelargonium gibbosum)
• subsection Polyactium de Candolle – 7 species

Subgenus Magnipetala: Corresponds to clade C1, with 24 species. Perennial to short lived, spreading subshrubs, rarely herbaceous annuals. Petals five, but may be four, colour mainly white. Mainly winter rainfall region of South Africa, spreading into summer rainfall region. One species in northern Namibia and Botswana. Two species in East Africa and Ethiopia. Chromosomes x=11 and 9.

Subgenus Parvulipetala: Corresponds to clade B, with 39-42 species. Perennials, partly annuals. Petals five and equal, colour white or pink to deep purplish red. Mainly South Africa, but also other southern hemisphere except South America. a few species in East Africa and Ethiopia. Chromosomes x=7-19.

Subgenus Paucisignata: Corresponds to clade C2, with 25-27 species. Erect sometimes trailing shrubs or subshrubs, rarely geophytes or semi-geophytes. Petals five and equal, colour pink to red sometimes white. Summer rainfall region of South Africa, spreading into winter rainfall region and northern Namibia, with a few species in tropical Africa, Ethiopia, Somalia, Madagascar, the Arabian Peninsula and Asia Minor. Chromosomes x=mainly 9 or 10, but from 4–18.

Subgenus Pelargonium: Corresponds to clade A, with 167 species. Frequently xerophytic deciduous perennials with many geophytes and succulent subshrubs, less frequently woody evergreen shrubs or annual herbs. Petals five, colour shades of pink to purple or yellow. Winter rainfall region of South Africa and adjacent Namibia, spreading to summer rainfall area, and two species in tropical Africa. Chromosomes x=11, may be 8–10.{{sfn|Roschenbleck et al|2014}}

{{main|List of Pelargonium species}}

Pelargonium has around 280 species.{{r|powo}}{{cite journal|last1=Weng|first1=ML|last2=Ruhlman|first2=TA|last3=Gibby|first3=M|author-link3=Mary Gibby|last4=Jansen|first4=RK|date=Sep 2012|title=Phylogeny, rate variation, and genome size evolution of Pelargonium (Geraniaceae)| journal=Mol Phylogenet Evol|volume=64|issue=3| pages=654–70|doi=10.1016/j.ympev.2012.05.026 |pmid=22677167|bibcode=2012MolPE..64..654W }} Röschenbleck et al lists 281 taxa.{{sfn|Roschenbleck et al|2014}} There is considerable confusion as to which Pelargonium are true species, and which are cultivars or hybrids. The nomenclature has changed considerably since the first plants were introduced to Europe in the 17th century.

File:Pelargon.jpg

The name Pelargonium is derived from the Greek πελαργός, pelargós (stork), because the seed head looks like a stork's beak. Dillenius originally suggested the name 'stork', because Geranium was named after a crane — "a πελαργός, ciconia, sicuti vocamus Gerania, γερανός, grus" (from pelargos, stork, as we call the Gerania, geranos, crane).{{sfn|Dillenius|1732|loc=[http://bibdigital.rjb.csic.es/ing/Libro.php?Libro=1386&Pagina=280 De Geraniorum Differentiis]}}{{sfn|Boddy|2013|loc=[https://books.google.com/books?id=24eoWcnoyfcC&pg=PR2 Introduction p. 11]}}

Pelargonium is a large genus within the family Geraniaceae, which has a worldwide distribution in temperate to subtropical zones with some 800 mostly herbaceous species.{{sfn|Roschenbleck et al|2014}} Pelargonium itself is native to southern Africa (including Namibia) and Australia. Southern Africa contains 90% of the genus, with only about 30 species found elsewhere, predominantly the East African rift valley (about 20 species) and southern Australia, including Tasmania.{{sfn|Roschenbleck et al|2014}} The remaining few species are found in southern Madagascar, Yemen, Iraq, Asia Minor, the north of New Zealand and isolated islands in the south Atlantic Ocean (Saint Helena and Tristan da Cunha) and Socotra in the Indian Ocean.{{sfn|Roschenbleck et al|2014}} The centre of diversity is in southwestern South Africa where rainfall is confined to the winter, unlike the rest of the country where rainfall is predominantly in the summer months.{{sfn|Roschenbleck et al|2014}} Most of the Pelargonium plants cultivated in Europe and North America have their origins in South Africa.{{cite web |last=Sayre |first=James K. |year=2003 |url=http://www.bottlebrushpress.com/scentedgeraniums.html |title=Scented Geraniums or Pelargoniums |publisher=Bottlebrushpress.com |url-status=dead |archive-url=https://web.archive.org/web/20110708085450/http://www.bottlebrushpress.com/scentedgeraniums.html |archive-date=2011-07-08}}

Pelargonium species are eaten by the caterpillars of some Lepidoptera species, including the noctuid moth angle shades, Phlogophora meticulosa. The diurnal butterflies Cacyreus marshalli and C. tespis (Lycaenidae), native to southern Africa, also feed on Geranium and Pelargonium.{{cite journal|title= Butterflies of Kwazulu-Natal|journal= Durban Natural Science Museum Novitates|url= http://www.durban.gov.za/City_Services/ParksRecreation/museums/nsm/publications/Documents/Novitates%2033.pdf}} C. marshallii has been introduced to Europe and can develop into a pest on cultivated Pelargoniums. It has naturalised along the Mediterranean, but does not survive the winter in Westen Europe.{{cite web|website= UK Butterflies|author= Peter Eeles|title= Geranium bronze|url= http://www.ukbutterflies.co.uk/species.php?species=marshalli|access-date= 2017-09-26}}

The Japanese beetle, an important agricultural insect pest, becomes rapidly paralyzed after consuming flower petals of the garden hybrids known as "zonal geraniums" (P. × hortorum). The phenomenon was first described in 1920, and subsequently confirmed.Davis, J.J. 1920. The green Japanese beetle. New Jersey Department of Agriculture Circular. 30: 33.{{cite journal|last1=Ballou|first1=C. H.|year=1929|title=Effects of geranium on the Japanese beetle| journal=Journal of Economic Entomology|volume=22|issue=2| pages=289–293|doi=10.1093/jee/22.2.289}}{{cite journal|last1=Potter|first1=D. A.|last2=Held|first2=D. W.|year=1999|title=Absence of food-aversion learning by a polyphagous scarab, Popillia japonica, following intoxication by geranium, Pelargonium x hortorum| journal=Entomologia Experimentalis et Applicata|volume=91| pages=83–88|doi=10.1046/j.1570-7458.1999.00468.x|s2cid=85069089}}{{cite journal|last1=Held|first1=D. W.|last2=Potter|first2=D. A.|year=2003|title=Characterizing toxicity of Pelargonium spp. and two other reputedly toxic plant species to Japanese beetles (Coleoptera: Scarabaeidae)| journal=Environmental Entomology|volume=32|issue=4| pages=873–880|doi=10.1603/0046-225x-32.4.873|doi-access=free}} Research conducted by Dr. Christopher Ranger with the USDA Agricultural Research Service and other collaborating scientists have demonstrated the excitatory amino acid called quisqualic acid present within the flower petals is responsible for causing paralysis of the Japanese beetle.[http://www.ars.usda.gov/is/AR/archive/mar10/garden0310.htm Geraniums and Begonias: New Research on Old Garden Favorites] (the March 2010 issue of Agricultural Research magazine.){{cite journal|author=Ranger, C.M.|author2=Winter, R. E.|author3=Singh, A. P.|author4=Reding, M. E.|author5=Frantz, J. M.|author6=Locke, J. C.|author7=Krause, C. R.|title=Rare excitatory amino acid from flowers of zonal geranium responsible for paralyzing the Japanese beetle|journal=Proceedings of the National Academy of Sciences|year=2011|volume=108|issue=4|pages=1217–1221|doi=10.1073/pnas.1013497108|url=http://www.pnas.org/content/early/2010/12/29/1013497108.full.pdf|pmid=21205899|pmc=3029778|bibcode=2011PNAS..108.1217R|doi-access=free}} Quisqualic acid is thought to mimic L-glutamic acid, which is a neurotransmitter in the insect neuromuscular junction and mammalian central nervous system.{{cite book|last1=Usherwood|first1=P. N. R.|title=Advances in Insect Physiology Volume 24|year=1994|chapter=Insect glutamate receptors| series=Advances in Insect Biochemistry and Physiology|volume=24| pages=309–341 |doi=10.1016/S0065-2806(08)60086-7|isbn=9780120242245}}

A study by the Laboratory of Apiculture & Social Insects group at the University of Sussex on the attractiveness of common garden plants to pollinators found that a cultivar of Pelargonium × hortorum was unattractive to pollinators in comparison to other selected garden plants such as Lavandula (lavender) and Origanum.{{cite journal|title=Quantifying variation among garden plants in attractiveness to bees and other flower-visiting insects|journal=Functional Ecology|year=2013|doi=10.1111/1365-2435.12178|volume=28|issue=2|pages=364–374|last1=Garbuzov|first1=Mihail|last2=Ratnieks|first2=Francis L. W.|s2cid=83908634 }}

{{Main|List of geranium diseases|Pelargonium flower break virus|Pelargonium line pattern virus}}

The geranium bronze butterfly is a pest of Pelargonium species. The larvae of the geranium bronze bore into the stem of the host plant, causing the stem to typically turn black and die soon after. Geranium bronze are currently listed as an A2 quarantine pest by the European and Mediterranean Plant Protection Organization and can cause significant damage to Pelargonium species.{{cite journal|last1=Martinou|first1=A.F.|last2=Papachristos|first2=D.|last3=Milonas|first3=P.G.|title=Report of the Geranium Bronze Butter y, Cacyreus marshalli for mainland Greece|journal=Hellenic Plant Protection Journal.|date=2011}}

File:1 Pelargonium triste - Kenwyn Nature Park - Cape Town a.jpg, the first species of its genus to be cultivated, here shown in its native habitat in Cape Town]]

Various types of Pelargonium are regular participants in flower shows and competitive events, with numerous societies devoted exclusively to their cultivation. They are easy to propagate vegetatively from cuttings.{{cite book |title=RHS A-Z encyclopedia of garden plants |year=2008 |publisher=Dorling Kindersley |location=United Kingdom |isbn=978-1405332965 |page=1136}}{{cite web |url=https://www.bbc.co.uk/gardening/basics/techniques/propagation_pelargoniums1.shtml |title=Gardening - Gardening Guides - Techniques - Taking pelargonium cuttings |work=BBC |date=1970-01-01 |access-date=2013-09-12}} It is recommended that cuttings should have at least two nodes.{{Cite web |last=Gardner |first=Eva |title=2023 How to Successfully Propagate Geranium in 5 Simple Steps |url=https://www.helpfulhomeadvice.com/green/propagate-geranium-in-5-steps/ |access-date=2023-06-02 |website=www.helpfulhomeadvice.com |date=2 June 2023 |language=en-US |url-status=dead|archive-url=https://web.archive.org/web/20230602030222/http://www.helpfulhomeadvice.com/green/propagate-geranium-in-5-steps/|archive-date=2023-06-02}} Zonal geraniums grow in U.S. Department of Agriculture hardiness zones 9 through 12. Zonal geraniums are basically tropical perennials. Although they are often grown as annuals, they may overwinter in zones as cool as zone 7.[https://homeguides.sfgate.com/minimum-temperatures-geranium-plants-66682.html Minimum Temperatures for Geranium Plants]

The first species of Pelargonium known to be cultivated was P. triste, a native of South Africa. It was probably brought to the Botanical Garden in Leiden before 1600 on ships which had stopped at the Cape of Good Hope. In 1631, the English gardener John Tradescant the elder bought seeds from Rene Morin in Paris and introduced the plant to England. By 1724, P. inquinans, P. odoratissimum, P. peltatum, P. vitifolium, and P. zonale had been introduced to Europe.{{sfn|Taylor|2014|loc=[https://books.google.com/books?id=RWuZBgAAQBAJ&pg=PT207 Pelargonium]}}

File:Pelargonium zonale (Geraniaceae).jpg

There was little attempt at any rational grouping of Pelargonium cultivars, the growing of which was revived in the mid-twentieth century, and the origins of many if not most were lost in obscurity. In 1916 the American botanist Liberty Hyde Bailey (1858–1954) introduced two new terms for zonal and regal pelargoniums. Those pelargoniums which were largely derived from P. zonale he referred to as P. × hortorum (i.e. from the garden), while those from P. cucullatum he named P. × domesticum (i.e. from the home).{{sfn|Wilkinson|2007|loc=[https://books.google.com/books?id=6787AwAAQBAJ&pg=PT189 p. 189]}}{{cite web |last=Handlos |first=Wayne |date=2010 |url=http://www.geraniumsonline.com/lhbailey.htm |title=Connections, Legacies, and Contributions:Liberty Hyde Bailey, Jr. |website=Geraniums Online |publisher=Central Coast Geranium Society |access-date=3 August 2017}} In the late 1950s a list (the Spalding List) was produced in the United States, based on nursery listings and the 1897 list of Henri Dauthenay.{{sfn|Dauthenay|1897}} It described seven groups, listing each cultivar with the list of its originator, and in most cases a date. These were Species, Zonals, Variegated-Leaved, Domesticum (Regals), Ivy-Leaved, Scented-Leaved and Old. In the 1970s the British Pelargonium and Geranium Society produced a checklist and the Australian Geranium Society started to produce a register but it was not completed till its author, Jean Llewellyn's death in 1999. None of these were published. The most complete list in its time was the 2001 compilation by The Geraniaceae Group,{{sfn|Amadio|2015}} which included all cultivars up to 1959.{{sfn|Wilkinson|2007|loc=[https://books.google.com/books?id=6787AwAAQBAJ&pg=PT220 Appendix 2: Horticultural Classification and Glossary]}}

Registration of cultivars is the responsibility of the Pelargonium & Geranium Society (PAGS: formed in 2009 from the British Pelargonium and Geranium Society and the British and European Geranium Society){{sfn|PAGS|2015|loc=[https://thepags.org/about-us/ About us]}} which administers the International Register of Pelargonium Cultivars.{{sfn|PAGS|2015|loc=[http://thepelargoniumregister.com/about-the-international-register-of-pelargonium-cultivars/ International Register of Pelargonium Cultivars]}} PAGS is the International Cultivar Registration Authority (ICRA) of the International Society for Horticultural Science for pelargoniums.{{sfn|ISHS|2015|loc=ICRA: [http://www.ishs.org/sci/icralist/73.htm Pelargonium and Geranium Society]}}

File:Pelargonium leavesIvyZonal.JPG

Cultivated pelargoniums are commonly divided into six groups{{sfn|RHS|2015|loc=[https://www.rhs.org.uk/advice/profile?PID=338 Pelargonium (geranium)]}} in addition to species pelargoniums and primary hybrids. The following list is ordered by position in the PAGS classification.{{sfn|PAGS|2015|loc=[https://thepags.org Pelargonium Basics]}} Abbreviations indicate Royal Horticultural Society usage.{{sfn|RHS|2015|loc=[http://apps.rhs.org.uk/horticulturaldatabase/genusclass_hd.asp?genus=Pelargonium Horticultural classification for Pelargonium L'Her. ex Aiton]}}

• A. Zonal (Z)
• B. Ivy-leaved (I)
• C. Regal (R)
• D. Angel (A)
• E. Unique (U)
• F. Scented-leaved (Sc)
• G. Species
• H. Primary hybrids

Of these, A, U and Sc groups are sometimes lumped together as Species Derived (Sppd). This term implies that they are closely related to a species from which they were derived, and do not fit into the R, I or Z groups.{{sfn|PAGS|2015|loc=[http://thepelargoniumregister.com/horticulture-symbols-and-terms/ Horticultural symbols and terms]}}

In addition to the primary groups, additional descriptors are used. The Royal Horticultural Society has created description codes. These include;{{sfn|RHS|2015|loc=[http://apps.rhs.org.uk/horticulturaldatabase/genusclass_hd.asp?genus=Pelargonium Horticultural classification for Pelargonium L'Her. ex Aiton]}}

• Cactus (Ca)
• Coloured foliage (C)
• Decorative (Dec)
• Double (d)
• Dwarf (Dw)
• Dwarf Ivy-leaved (Dwl)
• Frutetorum (Fr)
• Miniature (Min)
• Miniature Ivy-leaved (MinI)
• Stellar (St)
• Tulip (T)
• Variegated (v)

These may then be combined to form the code, e.g. Pelargonium 'Chelsea Gem' (Z/d/v), indicating Zonal Double with variegated foliage.{{cite web |title=Pelargonium 'Chelsea Gem' |url=https://www.rhs.org.uk/Plants/70117/Pelargonium-Chelsea-Gem-(Z-d-v)/Details?|publisher=Royal Horticultural Society}} Crosses between groups are indicated with an ×, e.g. Pelargonium 'Hindoo' (R × U), indicating a Regal × Unique cross.{{cite web |title=Pelargonium 'Hindoo'|url=https://www.rhs.org.uk/Plants/61250/Pelargonium-Hindoo-(R-×-U)/Details|publisher=Royal Horticultural Society}}

File:Pelargonium x hortorum.jpg

These are known as zonal geraniums because many have zones or patterns in the center of the leaves, this is the contribution of the Pelargonium zonale parent. Common names include storksbill, fish or horseshoe geraniums.{{sfn|PAGS|2015|loc=[http://thepelargoniumregister.com/horticulture-symbols-and-terms/ Horticultural symbols and terms]}} They are also referred to as Pelargonium × hortorum Bailey. Zonal pelargoniums are tetraploid, mostly derived from P. inquinans and P. zonale,{{PLANTS|id=PEHO2|taxon=Pelargonium ×hortorum|access-date=5 August 2017}} together with P. scandens and P. frutetorum.{{sfn|RHS|2015|loc=[https://www.rhs.org.uk/advice/profile?PID=338 Pelargonium (geranium)]}}

Zonal pelargoniums are mostly bush-type plants with succulent stems grown for the beauty of their flowers, traditionally red, salmon, violet, white or pink. The scarlet colouring is attributed to the contribution of P. inquinans.{{sfn|Taylor|2014|loc=[https://books.google.com/books?id=RWuZBgAAQBAJ&pg=PT207 Pelargonium]}} Flowers may be double or single. They are the pelargoniums most often confused with genus Geranium, particularly in summer bedding arrangements. This incorrect nomenclature is widely used in horticulture, particularly in North America.{{sfn|Taylor|2014|loc=[https://books.google.com/books?id=RWuZBgAAQBAJ&pg=PT207 Pelargonium]}}

Zonals include a variety of plant types along with genetic hybrids such as hybrid ivy-leaved varieties that display little or no ivy leaf characteristics (the Deacons varieties), or the Stellar varieties. Hybrid zonals are crosses between zonals and either a species or species-derived pelargonium.{{sfn|PAGS|2015|loc=[http://thepelargoniumregister.com/horticulture-symbols-and-terms/ Horticultural symbols and terms]}} There are hundreds of zonal cultivars available for sale,[http://www.hutchinsonfarm.ca/Flowers/GeraniumsZonal.html Hutchinson Farm: Zonal Geraniums] and like other cultivars are sold in series such as 'Rocky Mountain',[http://www.hutchinsonfarm.ca/Flowers/GeraniumRockies.html Hutchinson Farm: Rocky Mountain Geraniums] each of which is named after its predominant colour, e.g. 'Rocky Mountain Orange', 'White', 'Dark Red', etc.[http://utgardens.tennessee.edu/2008_results.asp?id=209 The University of Tennessee Gardens: Pelargonium x hortorum Rocky Mountain™ 'Dark Red']

File:Pelargonium 'Rocky Mountain Orange'2.jpg

• (i) Basic plants – Mature plants with foliage normally exceeding {{convert|180|mm|in|0|abbr=on}} in height above the rim of the pot. For exhibition these should be grown in a pot exceeding {{convert|120|mm|in|frac=4|abbr=on}} in diameter but not normally exceeding {{convert|165|mm|in|frac=2|abbr=on}}.
• (ii) Dwarf plants – Smaller than basic. Mature plants with foliage more than {{convert|125|mm|in|0|abbr=on}} above the rim of the pot, but not normally more than {{convert|180|mm|in|0|abbr=on}}. For exhibition should be grown in a pot exceeding {{convert|90|mm|in|frac=2|abbr=on}} but not exceeding {{convert|120|mm|in|frac=4|abbr=on}}. They should not exceed 200 mm in height, grown in an 11 cm pot.{{sfn|PAGS|2015|loc=[http://thepelargoniumregister.com/horticulture-symbols-and-terms/ Horticultural symbols and terms]}}
• (iii) Miniature plants – Slowly growing pelargoniums. Mature plants with foliage normally less than {{convert|125|mm|in|0|abbr=on}} above the rim of the pot. For exhibition should be grown in a pot not exceeding {{convert|90|mm|in|frac=2|abbr=on}}. They should not exceed 125 mm in height, grown in a 9 cm pot.{{sfn|PAGS|2015|loc=[http://thepelargoniumregister.com/horticulture-symbols-and-terms/ Horticultural symbols and terms]}}
• (iv) Micro-miniature plants – Smaller and more slowly growing than miniature pelargoniums. Mature plants with foliage normally less than {{convert|100|mm|in|0|abbr=on}} above the rim of the pot. They should not exceed 75 mm in height, grown in a 6 cm pot.{{sfn|PAGS|2015|loc=[http://thepelargoniumregister.com/horticulture-symbols-and-terms/ Horticultural symbols and terms]}} Usually no separate classes for these in exhibition and will therefore normally be shown as Miniature Zonals.
• (v) Deacon varieties –Genetic hybrid similar to a large Dwarf. For exhibition (when shown in a separate class), usually grown in a pot not exceeding {{convert|125|mm|in|0|abbr=on}}, otherwise as for Dwarf Zonals.
• (vi) Stellar varieties – A relatively modern genetic hybrid originating from the work done by the Australian hybridiser Ted Both in the late 1950s and 1960s from crosses between Australian species and Zonal types. Easily identifiable by their distinctive half-star-shaped leaves and slim-petalled blooms which create an impression of being star shaped (or five fingered). Single varieties tend to have larger elongated triangular petals whereas doubles tend to have thin feathered petals that are tightly packed together. For exhibition purposes there is a separate class for 'Stellar' varieties, but being Zonals could be shown in an open class for Basic, Dwarf or Miniature Zonals (unless otherwise stated). Also known as "The Five-fingered Geraniums", "Staphysagroides", "Both’s Staphs", "Both’s Hybrid Staphs", "Fingered Flowers" and "Bodey’s Formosum Hybrids".{{sfn|PAGS|2015|loc=[http://thepelargoniumregister.com/horticulture-symbols-and-terms/ Horticultural symbols and terms]}}

Fancy-leaf zonal pelargoniums – besides having green leaves with or without zoning, this group also have variable coloured foliage{{sfn|PAGS|2015|loc=[http://thepelargoniumregister.com/horticulture-symbols-and-terms/ Horticultural symbols and terms]}} that is sometimes used in classifying for exhibition purposes, e.g. ‘Bicolour’, ‘Tricolour’, ‘Bronze’ or ‘Gold’. Other foliage types are: ‘Black’ or ‘Butterfly’. There are an increasing number of these plants with showy blooms;

• (a) Bicolour – includes those with white or cream veined leaves or those with two distinct colours with clearly defined edges, other than the basic zone.
• (b) Tricolour – (May be Silver Tricolour (usually called a Silver Leaf) or a Gold Tricolour).
• (i) Gold Tricolour – Leaves of many colours including red and gold, but usually with clearly defined edges of golden yellow and having a leaf zone, usually red or bronze, that overlays two or more of the other distinct leaf colours, so that the zone itself appears as two or more distinct colours.
• (ii) Silver Tricolour or Silver Leaf – These tend to resemble a normal bi-colour leaf plant with two distinct colours usually of green and pale cream or white; the third colour is usually made up of bronze zoning. When this zoning overlays the green part of the leaf it is deemed to represent a silver colour.
• (c) Bronze Leaved – Leaves of Green or Golden/Green with a heavy bronze or chestnut coloured centre zone which is known as a medallion. For exhibition purposes, when exhibited in specific ‘Bronze’ Leaf class – Must have over 50% of leaf surface bronze coloured. The dwarf plant ‘Overchurch’ which has a heavy bronze medallion.
• (d) Gold Leaved – Leaves coloured golden/yellow or green/yellow but not showing a tendency to green. For exhibition purposes, when exhibited in specific ‘Gold’ Leaf class – Must have over 50% of leaf surface gold coloured.
• (e) Black Leaved – Leaves coloured black, purple-black or with distinct large dark zones or centre markings on green.
• (f) Butterfly Leaved – Leaves with a butterfly marking of distinct tone or hue in centre of leaf. This can be encompassed in many of the coloured leaf varieties.

Zonal pelargoniums have many flower types, as follows:{{sfn|PAGS|2015|loc=[http://thepelargoniumregister.com/horticulture-symbols-and-terms/ Horticultural symbols and terms]}}

• (a) Single flowered (S) – each flower pip normally having no more than five petals. This is the standard flower set for all Pelargoniums.
• (b) Semi-double flowered (SD) – each flower pip normally having between six and nine petals.
• (c) Double flowered (D)– each flower pip composed of more than nine petals (i.e. double the standard flower set) but not ‘hearted’ like the bud of a rose, e.g. the dwarf ‘Dovepoint’ which has full double blooms.
• (d) Rosebud (or noisette) flowered – each bloom fully double and ‘hearted’. The middle petals are so numerous that they remain unopened like the bud of a rose.{{sfn|PAGS|2015|loc=[http://thepelargoniumregister.com/horticulture-symbols-and-terms/ Horticultural symbols and terms]}}
• (e) Tulip flowered – having semi-double blooms that never fully open. The large cup shaped petals open just sufficiently to resemble a miniature tulip.
• (f) Bird's-egg group – having blooms with petals that have spots in a darker shade than the base colour, like many birds eggs.{{sfn|PAGS|2015|loc=[http://thepelargoniumregister.com/horticulture-symbols-and-terms/ Horticultural symbols and terms]}}
• (g) Speckled flowered group – having petals that are marked with splashes and flecks of another colour, e.g. ‘Vectis Embers’.
• (h) Quilled (or cactus-flowered group, or poinsettia in USA) – having petals twisted and furled like a quill.{{sfn|PAGS|2015|loc=[http://thepelargoniumregister.com/horticulture-symbols-and-terms/ Horticultural symbols and terms]}}

“Zonquil” pelargoniums result from a cross between Zonal pelargonium cultivars and P. quinquelobatum.{{sfn|PAGS|2015|loc=[http://thepelargoniumregister.com/horticulture-symbols-and-terms/ Horticultural symbols and terms]}}

File:Geraniaceae.jpg (Ivy-leaved)]]

Also known as "ivy geraniums".{{sfn|PAGS|2015|loc=[http://thepelargoniumregister.com/horticulture-symbols-and-terms/ Horticultural symbols and terms]}}Usually of lax growth (trailing), mainly due to the long thin stems, with thick, waxy ivy-shaped stiff fleshy evergreen leaves developed by the species P. peltatum to retain moisture during periods of drought. Much used for hanging pots, tubs and basket cultivation. In the UK the bulbous double-headed types are preferred whilst on the European continent the balcon single types for large-scale hanging floral displays are favoured. Ivy-leaved pelargoniums embrace all such growth size types including small-leaved varieties and genetic hybrid crosses, which display little or no zonal characteristics. May have bicolour leaves and may have flowers that are single, double or rosette. Ivy pelargoniums are often sold as series such as 'Great Balls of Fire', in a variety of colours such as 'Great Balls of Fire Burgundy'.

Additional descriptive terms include;{{sfn|PAGS|2015|loc=[http://thepelargoniumregister.com/horticulture-symbols-and-terms/ Horticultural symbols and terms]}}

• Hybrid Ivy — the result of ivy × zonal crosses, but still more closely resemble ivy-leaved pelargoniums.
• Fancy leaf — leaves with marked color variation, together with or other than green.
• Miniature — miniature leaves and flowers, stems with short nodes, and compact growth. e.g. 'Sugar Baby'{{cite web |title=Pelargonium 'Sugar Baby' |url=https://www.rhs.org.uk/Plants/51136/Pelargonium-Sugar-Baby-(DwI)/Details |publisher=Royal Horticultural Society}} listed as Dwarf Ivy (DwI) by RHS.{{sfn|RHS|2015|loc=[http://apps.rhs.org.uk/horticulturaldatabase/genusclass_hd.asp?genus=Pelargonium Horticultural classification for Pelargonium L'Her. ex Aiton]}}

File:Pelargonium karl offenstein.jpg

These are large bush-type floriferous evergreen pelargoniums. In addition to "Regals" they are also known as “Show Pelargoniums”. In the United States they are often known as the "Martha Washington" or ‘"Lady Washington" pelargoniums. They are grown primarily for the beauty and richness of their flower heads, which are large. Most of those cultivars grown currently are the result of hybridization over the last 50 years. They are very short-jointed and compact, which results in their requiring very little work in order to create a floriforous and well-rounded plant.{{sfn|PAGS|2015|loc=[http://thepelargoniumregister.com/horticulture-symbols-and-terms/ Horticultural symbols and terms]}}{{sfn|PAGS|2015|loc=[https://thepags.org Pelargonium Basics]}} Flowers are single, rarely double, in mauve, pink, purple or white. They have rounded, sometimes lobed or partially toothed (serrated) leaves, unlike the Zonal groups, without any type of zoning.

Additional descriptive terms include;{{sfn|PAGS|2015|loc=[http://thepelargoniumregister.com/horticulture-symbols-and-terms/ Horticultural symbols and terms]}}

• Fancy leaf – Leaves with marked variations in colour
• Decorative pelargoniums (Decoratives) – Descendants of older, less compact, smaller-flowered varieties that are more suited to outdoor conditions. These have smaller flowers than Regal, but are otherwise similar. e.g. ‘Royal Ascot’
• Miniature – Flowers and leaves similar to Regal, but miniature in form, with compact growth. Other terms include “Pansy Geraniums” or “Pansy Pelargoniums”. e.g. ‘Lara Susan’
• Oriental pelargoniums – The result of crosses between Regals and members of the Angel group (see below). Some have bicolour foliage.

File:Angeleyes Randy.jpg

Angel pelargoniums are similar to Regal pelargoniums but more closely resemble P. crispum in leaf shape and growth habit. The majority of Angel cultivars originate from a cross between P. crispum and a Regal variety in the early part of the 20th century. Angels have grown in popularity in the last 30 years or so due mainly to an explosion of new varieties being released by specialist nurseries resulting from the work done by dedicated amateur hybridisers. These hybrisers have managed to obtain many new flower colour breaks and tighter growth habits resulting in plants suitable for all sorts of situations. Angels basically have the appearance of a small Regal with small serrated leaves and much smaller flowers and are more compact and bushy. The group extends to include similar small-leaved and -flowered types but usually with P. crispum in their parentage. They are mostly upright bush-type plants but there are some lax varieties that can be used for basket or hanging pot cultivation. Often called "pansy-faced" in the US. Some varieties have bicolour foliage. Other terms include ‘Langley-Smith Hybrids’.{{sfn|PAGS|2015|loc=[http://thepelargoniumregister.com/horticulture-symbols-and-terms/ Horticultural symbols and terms]}}

Image:Pelargonium White Unique.jpg

Unique in sense of not fitting into any of the above categories. The parentage of Unique pelargoniums is confused and obscure. One theory being a derivation from P. fulgidum, but a derivation from an older cultivar 'Old Unique’, also known as or ‘Rollinson’s Crimson’, in the mid-19th century is also claimed.{{sfn|PAGS|2015|loc=[http://thepelargoniumregister.com/horticulture-symbols-and-terms/ Horticultural symbols and terms]}} Unique pelargoniums resemble upright Scented Leaf pelargoniums in being shrubby and woody evergreens. They have distinctly scented leaves, and small flowers with blotched and feathered petals. They may have bicolour foliage. Some types, popularly known in the hobby as hybrid Uniques, have been crossed with Regal pelargoniums and, as a result of this cross, are much more floriferous.

; Cultivar:

• Fiery-flowered Stork's-bill, Scarlet Unique Scented Geranium (P. × ignescens){{sfn|Sweet|1822|loc=[https://www.biodiversitylibrary.org/item/182545#page/25/mode/1up Pelargonium ignescens]}} - a P. fulgidum hybrid{{cite web |last=Cornett |first=Peggy |date=2013 |url=https://www.monticello.org/site/research-and-collections/pelargonium-fulgidum-hybrid-scarlet-unique-geranium |title=Pelargonium fulgidum hybrid - Scarlet Unique Geranium |website=Monticello.org |publisher=Thomas Jefferson Encyclopedia |access-date=3 August 2017}}

Image:Pelargonium graveolens 2.jpg (Scented leaf)]]

Shrubby evergreen perennials grown chiefly for their fragrance, may be species or cultivars but all must have a clear and distinct scented foliage. Scent is emitted when the leaves are touched or bruised with some scents aromatic, others pungent and in a few cases, quite unpleasant. Several of the scented leaved pelargoniums are grown for the oil geraniol, which is extracted from the leaves and is an essential oil much used commercially in perfumery. The scent of some species growing in their natural habitat, acts as a deterrent to grazing animals who appear to dislike the emitted scent. Conversely, it also attracts other insect life to visit the bloom and pollinate the plant. The scented leaves can be used for potpourri and they also have a use as flavourings in cooking. Occasionally scented types can be found in some of the other groups mentioned; for example, the Angels, having P. crispum in their genetic makeup, can often have a strong citrus scent. Leaves are lobed, toothed, incised or variegated. Growth habit is very variable, but the flowers are less prominent than other groups, and most closely resemble the species they originated from.{{sfn|PAGS|2015|loc=[http://thepelargoniumregister.com/horticulture-symbols-and-terms/ Horticultural symbols and terms]}}

These include:

Image:Fair Ellen.jpg 'Fair Ellen' (Scented leaf)]]

Image:Pelargonium ionidiflorum 1.jpg (Scented leaf)]]

• Almond - Pelargonium quercifolium
• Apple - Pelargonium odoratissimum
• Apple - Pelargonium cordifolium
• Apple/Mint - Pelargonium album
• Apricot/Lemon - Pelargonium scabrum
• Balsam - Pelargonium panduriforme
• Camphor - Pelargonium betulinum
• Celery - Pelargonium ionidiflorum
• Cinnamon - Pelargonium 'Ardwyck Cinnamon'
• Coconut - Pelargonium grossalarioides (Pelargonium parriflorum)
• Eau de Cologne - Pelargonium 'Brilliantine'
• Eucalyptus - Pelargonium 'Secret Love'
• Grapefruit - Pelargonium 'Poquita'
• Ginger - Pelargonium 'Torrento' or 'Cola Bottles' which is a variety of Pelargonium x nervosum
• Hazelnut - Pelargonium 'Odorata Hazelnut
• Lavender - Pelargonium 'Lavender Lindy'
• Lemon - Pelargonium crispum
• Lemon - Pelargonium citronellum (Synonym - Pelargonium 'Mabel Grey')
• Lemon Balm - Pelargonium x melissinum
• Lime - Pelargonium x nervosum
• Myrrh - Pelargonium myrrhifolium
• Nutmeg - Pelargonium x fragrans
• Old Spice - Variety of Pelargonium x fragrans
• Orange - Pelargonium x citriodorum (Synonym - Pelargonium 'Prince of Orange')
• Peach - Pelargonium 'Peaches and Cream'
• Peppermint - Pelargonium tomentosum
• Pine - Pelargonium denticulatum
• Pineapple - Pelargonium 'Brilliant'
• Raspberry - Pelargonium 'Red Raspberry'
• Rose - Pelargonium graveolens (Synonym - Pelargonium roseum)
• Rose - Pelargonium capitatum
• Rose - Pelargonium radens
• Southernwood - Pelargonium abrotanifolium
• Spicy - Pelargonium exstipulatum
• Strawberry - Pelargonium x scarboroviae

; Cultivars:

• 'Attar of Roses' - a cultivar of P. capitatum
• 'Crowfoot Rose' - a cultivar of P. radens
• 'Dr. Livingston' - a cultivar of P. radens
• 'Grey Lady Plymouth' - a cultivar of P. graveolens
• 'Prince Rupert' - a cultivar of P. crispum

The species are the forefathers of all the cultivar groups listed above. In general, the definition of a species is that it breeds true, and is to be found doing this in the "wild". Species pelargoniums have a large diversity of characteristics in habit, shape, size and colour, which probably accounts for them having retained their popularity for more than 300 years.

A primary hybrid is recognised as being the resultant plant from a first-time cross between two different known species. Examples are P. × ardens – from P. lobatum × P. fulgidum (1810). P. × glauciifolium – from P. gibbosum × P. lobatum (1822). Usually, but not always, primary hybrids are sterile.

File:Pelargonium-attarofroses.jpg

File:Pelargoniumladyplymouth.jpg

File:PelargoniumcitronellumMG.JPG

The following is a selection of pelargoniums which have gained the Royal Horticultural Society's Award of Garden Merit:

• 'Attar of Roses' (rose scented leaves, pink flowers){{cite web|title=Pelargonium 'Attar of Roses'|url=https://www.rhs.org.uk/Plants/59357/Pelargonium-Attar-of-Roses-(Sc)/Details|publisher=Royal Horticultural Society | access-date = 25 January 2021}}
• 'Citriodorum' (lemon scented leaves, rose pink flowers){{cite web|title=Pelargonium 'Citriodorum'|url=https://www.rhs.org.uk/Plants/51572/Pelargonium-Citriodorum-(Sc)/Details|publisher=Royal Horticultural Society | access-date = 16 January 2021}}
• 'Dolly Varden' (variegated leaves, scarlet flowers){{cite web|title=Pelargonium 'Dolly Varden'|url=https://www.rhs.org.uk/Plants/79978/Pelargonium-Dolly-Varden-(Z-v)/Details|publisher=Royal Horticultural Society | access-date = 16 January 2021}}
• 'Frank Headley' (cream vareigated leaves, salmon pink flowers){{cite web|title=Pelargonium 'Frank Headley'|url=https://www.rhs.org.uk/Plants/79978/Pelargonium-Dolly-Varden-(Z-v)/Details|publisher=Royal Horticultural Society| access-date = 16 January 2021}}
• 'Fringed Aztec' (white & purple fringed flowers){{cite web|title=Pelargonium 'Fringed Aztec'|url=https://www.rhs.org.uk/Plants/44812/Pelargonium-Fringed-Aztec-(R)/Details|publisher=Royal Horticultural Society|access-date = 16 January 2021}}
• 'Gemstone' (scented leaves, pink flowers){{cite web|title=Pelargonium 'Gemstone'|url=https://www.rhs.org.uk/Plants/54834/Pelargonium-Gemstone-(Sc)/Details|publisher=Royal Horticultural Society| access-date = 16 January 2021}}
• 'Grace Thomas' (lemon scented leaves, pale pink flowers){{cite web|title=Pelargonium 'Grace Thomas'|url=https://www.rhs.org.uk/Plants/110630/Pelargonium-Grace-Thomas-(Sc)/Details|publisher=Royal Horticultural Society| access-date = 16 January 2021}}
• 'Joy' (pink & white frilled flowers){{cite web|title=Pelargonium 'Joy'|url=https://www.rhs.org.uk/Plants/105735/Pelargonium-Joy-(R)/Details|publisher=Royal Horticultural Society| access-date = 16 January 2021}}
• 'Lady Plymouth' (P. graveolens variegata - small mauve flowers){{cite web|title=Pelargonium 'Lady Plymouth'|url=https://www.rhs.org.uk/Plants/83501/Pelargonium-Lady-Plymouth-(Sc-v)/Details|publisher=Royal Horticultural Society| access-date = 16 January 2021}}
• 'Lara Candy Dancer' (scented leaves, pale mauve flowers){{cite web|title=Pelargonium 'Lara Candy Dancer'|url=https://www.rhs.org.uk/Plants/111945/Pelargonium-Lara-Candy-Dancer-(Sc)/Details|publisher=Royal Horticultural Society| access-date = 16 January 2021}}
• 'Lara Starshine' (aromatic leaves, lilac flowers){{cite web|title=Pelargonium 'Lara Starshine'|url=https://www.rhs.org.uk/Plants/75161/Pelargonium-Lara-Starshine-(Sc)/Details|publisher=Royal Horticultural Society| access-date = 16 January 2021}}
• 'L'Élégante' (ivy-leaved, trailing, white and purple flowers){{cite web|title=Pelargonium 'L'Élégante'|url=https://www.rhs.org.uk/Plants/77226/Pelargonium-L-elegante-(I-v)/Details|publisher=Royal Horticultural Society|access-date = 16 January 2021}}
• 'Mabel Grey' (lemon-scented leaves, mauve flowers){{cite web|title=Pelargonium 'Mabel Grey'|url=https://www.rhs.org.uk/Plants/46345/Pelargonium-Mabel-Grey-(Sc)/Details|publisher=Royal Horticultural Society| access-date = 16 January 2021}}
• 'Mrs Quilter' (bronze leaves, salmon pink flowers){{cite web|title=Pelargonium 'Mrs Quilter'|url=https://www.rhs.org.uk/Plants/71148/Pelargonium-Mrs-Quilter-(Z-C)/Details|publisher=Royal Horticultural Society| access-date = 16 January 2021}}
• 'Radula' (lemon & rose scented leaves, pink & purple flowers){{cite web|title=Pelargonium 'Radula'|url=https://www.rhs.org.uk/Plants/119280/Pelargonium-Radula-(Sc)/Details|publisher=Royal Horticultural Society| access-date = 16 January 2021}}
• 'Royal Oak' (balsam scented leaves, mauve flowers){{cite web|title=Pelargonium 'Royal Oak'|url=https://www.rhs.org.uk/Plants/74032/Pelargonium-Royal-Oak-(Sc)/Details|publisher=Royal Horticultural Society| access-date = 16 January 2021}}
• 'Spanish Angel' (lilac & magenta flowers){{cite web|title=Pelargonium 'Spanish Angel'|url=https://www.rhs.org.uk/Plants/85682/Pelargonium-Spanish-Angel-(A)/Details|publisher=Royal Horticultural Society| access-date = 16 January 2021}}
• 'Sweet Mimosa' (balsam-scented leaves, pale pink flowers){{cite web|title=Pelargonium 'Sweet Mimosa'|url=https://www.rhs.org.uk/Plants/83869/Pelargonium-Sweet-Mimosa-(Sc)/Details|publisher=Royal Horticultural Society| access-date = 16 January 2021}}
• 'Tip Top Duet' (pink & wine-red flowers){{cite web|title=Pelargonium 'Tip Top Duet'|url=https://www.rhs.org.uk/Plants/45720/Pelargonium-Tip-Top-Duet-(A)/Details|publisher=Royal Horticultural Society| access-date = 16 January 2021}}
• 'Voodoo' (crimson & black flowers){{cite web|title=Pelargonium 'Voodoo'|url=https://www.rhs.org.uk/Plants/59491/Pelargonium-Voodoo-(U)/Details|publisher=Royal Horticultural Society| access-date = 16 January 2021}}
• P. tomentosum (peppermint-scented leaves, small white flowers){{cite web|title=Pelargonium tomentosum|url=https://www.rhs.org.uk/Plants/46730/Pelargonium-tomentosum-(Sc)/Details|publisher=Royal Horticultural Society| access-date = 16 January 2021}}

Pelargoniums rank as one of the highest number of potted flowering plants sold and also in terms of wholesale value.

Other than being grown for their beauty, species such as P. graveolens are important in the perfume industry and are cultivated and distilled for their scents. Although scented pelargoniums exist which have smells of citrus, mint, pine, spices or various fruits, the varieties with rose scents are most commercially important.{{citation needed|date=July 2012}} Pelargonium distillates and absolutes, commonly known as "scented geranium oil" are sometimes used to supplement or adulterate expensive rose oils. The oils of the scented pelargoniums contain citronellol, geraniol, eugenol, alpha-pinene and many other compounds. The edible leaves and flowers are also used as a flavouring in desserts, cakes, jellies and teas. Scented-leafed pelargoniums can be used to flavor jellies, cakes, butters, ice cream, iced tea and other dishes, The rose-, lemon- and peppermint-scents are most commonly used. Also used are those with hints of peach, cinnamon and orange. Commonly used lemon-scented culinary species include P. crispum and P. citronellum. Rose-scenteds include P. graveolens and members of the P. graveolens cultivar group. Other species and cultivars with culinary use include the lime-scented P. ‘Lime’, the lemon balm-scented P. ‘Lemon Balm’, the strawberry-lemon-scented P. ‘Lady Scarborough’ and the peppermint-scented P. tomentosum.{{cite web|title=Pelargoniums - An Herb Society of America Fact Sheet|url=http://www.herbsociety.org/factsheets/pelargoniums_fact.pdf|publisher=The Herb Society of America|year=2006|access-date=20 December 2012|url-status=dead|archive-url=https://web.archive.org/web/20120227124006/http://www.herbsociety.org/factsheets/pelargoniums_fact.pdf|archive-date=27 February 2012}} Scented leaf pelargoniums have also been historically used as toilet paper by fishermen in remote places, such as the Minquiers.{{Cite web |last=Stables |first=Daniel |title=The British islands that disappear every day |url=https://www.bbc.com/travel/article/20220828-the-british-islands-that-disappear-every-day |access-date=2022-08-30 |website=www.bbc.com |date=29 August 2022 |language=en}}

In herbal medicine, Pelargonium has been used for intestinal problems, wounds and respiratory ailments, but Pelargonium species have also been used for fevers, kidney complaints and other conditions. Geranium (Pelargonium) oil is considered a relaxant in aromatherapy, and in recent years, respiratory/cold remedies made from P. sidoides and P. reniforme have been sold in Europe and the United States. P. sidoides along with Echinacea is used for bronchitis.{{cite web|title=Pelargonium sidoides (African geranium)|url=http://www.wholehealthchicago.com/3406/pelargonium-sidoides-african-geranium/|publisher=WholeHealth Chicago|date=2010-02-14}} P. odoratissimum is used for its astringent, tonic and antiseptic effects. {{citation needed|date=May 2016}} It is used internally for debility, gastroenteritis, and hemorrhage and externally for skin complaints, injuries, and neuralgia and throat infections. The essential oil is used in aromatherapy.{{cite web|title=Apple Geranium |url=http://www.naturalmedicinalherbs.net/herbs/p/pelargonium-odoratissimum=apple-geranium.php |publisher=Natural Medicinal Herbs}}

According to the ASPCA, these plants are toxic to cats, dogs, and horses.{{cite web |url=https://www.aspca.org/pet-care/animal-poison-control/toxic-and-non-toxic-plants/geranium |title=Pet Care: Animal Poison Control: Toxic and Non-Toxic Plants: Geranium |publisher=American Society for the Prevention of Cruelty to Animals}}

Pelargonin (pelargonidin 3,5-O-diglucoside) is a petal pigment of the scarlet pelargonium.{{cite journal|last1=Saunders Currey|first1=Geoffrey|year=1922|title=The Colouring Matter of the Scarlet Pelargonium|url=https://zenodo.org/record/2077799| journal=J. Chem. Soc., Trans.|volume=121| pages=319–323|doi=10.1039/CT9222100319}}

Chemist John Dalton realized that he was color blind in 1794 when he heard others describe the color of the flowers of the pink Pelargonium zonale{{cite journal|last=Hunt|first=D. M.|author2=K. S. Dulai |author3=J. K. Bowmaker|author4= J. D. Mollon|title=The chemistry of John Dalton's color blindness|journal=Science|year=1995|volume=267|issue=5200|pages=984–988|doi=10.1126/science.7863342|pmid=7863342|bibcode=1995Sci...267..984H|s2cid=6764146}} as pink or red, when to him it looked either pink or blue, having no relationship to red at all.{{cite journal|last=Dalton|first=John|title=Extraordinary facts relating to the vision of colours: with observations.|journal=Memoirs of the Literary and Philosophical Society of Manchester|year=1798|volume=5|pages=28–45}}

{{notelist}}

{{Reflist|30em|refs=

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{{cite web |title=Pelargonium L'Hér. ex Aiton |url=https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:30302759-2 |website=Plants of the World Online |publisher=Royal Botanic Gardens, Kew |access-date=2 August 2020}}

• [http://www.pelargonium.si/ The Pelargonium Page]

}}

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• {{cite book |url=http://bibdigital.rjb.csic.es/ing/Libro.php?Libro=1386 |last=Dillenius |first=Johann Jakob |author-link=Dillenius |title=Hortus Elthamensis seu Plantarum Rariorum ... |publisher=Sumptibus Auctoris |location=London |date=1732 |access-date=26 July 2015 |language=la |archive-date=4 March 2016 |archive-url=https://web.archive.org/web/20160304205341/http://bibdigital.rjb.csic.es/ing/Libro.php?Libro=1386 |url-status=dead }}
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{{refend}}

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• {{cite journal |last1=Aedo |first1=Carlos |last2=Garmendia |first2=Félix Muñoz |title=Some Notes on the Sectional Nomenclature of Geranium (Geraniaceae) |journal=Taxon |volume=45 |issue=1 |date=Feb 1996 |pages=104–106 |doi=10.2307/1222593 |jstor=1222593 |bibcode=1996Taxon..45..104A |name-list-style=amp}}
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• {{cite thesis |last=Lalli |first=Jacqueline Yolande Yvette |date=2005 |title=In Vitro Pharmacological Properties and Composition of Leaf Essential Oils and Extracts of Selected Indigenous Pelargonium (Geraniaceae) Species |type=MPharm |publisher=University of the Witwatersrand |url=http://wiredspace.wits.ac.za/bitstream/handle/10539/1690/Dissertation.pdf |access-date=7 August 2017 }}
• {{cite journal|last1=Röschenbleck|first1=J|last2=Albers|first2=F|last3=Müller|first3=K|last4=Weinl|first4=S|last5=Kudla|first5=J |title=Phylogenetics, character evolution and a subgeneric revision of the genus Pelargonium (Geraniaceae) |journal=Phytotaxa |date=11 February 2014 |volume=159 |issue=2 |pages=31–76 |url=http://www.mapress.com/phytotaxa/content/2014/f/p00159p076f.pdf |ref={{harvid|Roschenbleck et al|2014}} |name-list-style=amp|doi=10.11646/phytotaxa.159.2.1|bibcode=2014Phytx.159...31R}}
• {{cite journal|last1=van der Walt|first1=J.J.A.|title=Notes on the nomenclature of Pelargonium Geraniaceae|journal=Journal of South African Botany|date=1979|volume=45|issue=3 |pages=377–380|doi=10.5962/p.396918 |url=http://eurekamag.com/research/006/000/006000979.php|access-date=14 July 2015}}
• {{cite journal|last1=van der Walt|first1=J.J.A.|last2=Vorster|first2=P.J.|title=Typification of the Genus Pelargonium L'Hérit. (Fam. Geraniaceae)|journal=Taxon|date=February 1981|volume=30|issue=1|pages=307|doi=10.2307/1219408|jstor=1219408 |bibcode=1981Taxon..30..307V |name-list-style=amp}}

{{refend}}

{{refbegin|40em}}

• {{cite web|last1=ISHS|title=International Society for Horticultural Science|url=http://www.ishs.org/|access-date=13 July 2015|date=2015|author1-link=International Society for Horticultural Science}}
• {{cite web|last1=RHS|title=Royal Horticultural Society|url=https://www.rhs.org.uk/|access-date=19 June 2015|date=2015|author1-link=Royal Horticultural Society}}
• {{cite web|last1=PAGS|title=The Pelargonium & Geranium Society|url=https://thepags.org/|access-date=25 Jan 2023|date=2023}}
• {{cite web|last1=AGS|title=Australian Geranium Society|url=http://www.australiangeraniumsociety.org.au/|access-date=8 July 2015|date=2014}}
• {{cite web|last1=HSA|title=The Herb Society of America|url=http://www.herbsociety.org/|access-date=12 July 2015|date=2015|archive-date=24 September 2015|archive-url=https://web.archive.org/web/20150924025744/http://www.herbsociety.org/factsheets/Pelargonium%20Guide.pdf|url-status=bot: unknown}}**
• {{cite web|last1=Amadio|first1=Marisa|title=The Geraniaceae Group|url=http://www.geraniaceae-group.org/|access-date=13 July 2015|date=2015}}

{{refend}}

{{Commons category}}

• [http://www.pelargonium.si/ The Pelargonium Page: descriptions of botanical species with plant and habitat photos, illustrations and literature]
• [http://www.pacificbulbsociety.org/pbswiki/index.php/Pelargonium Pacific Bulb Society: Pelargonium (tuberous species)]

{{Taxonbar|from=Q146118}}

{{Authority control}}

Category:Geraniales genera

Category:Garden plants

Category:Medicinal plants

Category:Taxa named by Charles Louis L'Héritier de Brutelle