Itoa
{{Short description|Genus of flowering plants}}
{{Automatic taxobox
| image = Itoa orientalis - Chengdu Botanical Garden - Chengdu, China - DSC03468.JPG
| image_caption = Itoa orientalis in Chengdu Botanical Garden, China
| display_parents = 2
| taxon = Itoa
| authority = Hemsl.
| subdivision_ranks = Species
| subdivision = 2; see text
| synonyms = *Mesaulosperma Slooten
}}
Itoa is a genus of flowering plants in the family Salicaceae.{{cite web |title=Itoa Hemsl. {{!}} Plants of the World Online {{!}} Kew Science |url=https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:291626-2 |website=Plants of the World Online |access-date=5 October 2021 |language=en}} It is also in the tribe Saliceae.{{cite journal |last1=Boucher |first1=Lisa D. |last2=Manchester |first2=Steven R. |last3=Judd |first3=Walter S. |title=An extinct genus of Salicaceae based on twigs with attached flowers, fruits, and foliage from the Eocene Green River Formation of Utah and Colorado, USA |journal=American Journal of Botany |date=September 2003 |volume=90 |issue=9 |pages=1389–1399|doi=10.3732/ajb.90.9.1389 |pmid=21659238 }}
Its native range is southern China to Vietnam, central and eastern Malesia to New Guinea. It is found in China (Hainan), Maluku Islands, New Guinea, Sulawesi and Vietnam.
Itoa orientalis is grown as an ornamental tree in Australia, Cornwall, UK,Peter Clough and Philip McMillan Browse {{google books|r_Tbv5uNky8C|Gardening on the Edge: Drawing on the Cornwall Experience (2004)|page=43}} and Ireland.Royal Horticultural Society {{google books|A9EjAQAAMAAJ|The Garden, Volume 126, Pages 743-955, 2001|page=868}} Itoa stapfii is found in Papua New Guinea.Barry J Conn and Kipiro Q Damas {{google books|ZMCSDwAAQBAJ|Trees of Papua New Guinea: Volume 1: Introduction and Gnetales to Fabales (2019)|page=52}}
Description
An evergreen tree with broad leaves,{{cite web |title=Itoa orientalis |url=https://www.farreachesfarm.com/Itoa-orientalis-p/p6165.htm |website=Far Reaches Farm |access-date=5 October 2021 |language=en}} that are alternate, sometimes sub-opposite placed.{{cite web |title=Itoa in Flora of China @ efloras.org |url=http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=116647 |website=www.efloras.org |access-date=5 October 2021}} The leaf blade is pinnate-veined with lateral veins closely set, mostly 1-2 cm apart.
The yellow buff flowers, are unisexual, hypogynous (borne below the ovary), The staminate flowers (male flower, flower with stamens but no pistil) are in erect, terminal panicles. The pistillate flowers (a flower containing one or more pistils but no stamens, female flower) has 1 to few in short terminal or axillary racemes. It has bracts and the bracteoles (small bracts) are a pair per pedicel, usually caducous (falling off early). The sepals appearing 3 or 4-merous in bud, in fact to 5-merous at anthesis (at time of flowering), nearly free, valvate, ovate shaped, with base appearing to be cordate (heart-shaped). The staminate flowers have many stamens with filaments free and filiform (thread-like). The anthers are ellipsoid to oblong in shape, basifixed, connective usually curved, bringing both locules (chambers) to face in same direction (towards the periphery of flower). The pistillate flowers have ovary superior, 1-loculed; placentas are 6-8, rarely 5, filiform and have a woody-like end. The ovules are numerous with 6-8 styles, which are very short, connate (cone-like), forming a short longitudinally ribbed column. The stigmatic branches (4-) 6-8 are spreading or strongly reflexed against the ovary and irregularly palmately lobed. The many staminodes (sterile stamen) are extragynoecial, like the stamens but very much reduced. The seed capsule is ovoid or ellipsoid in shape, large, woody, tomentose (covered in hairs), outer layer probably finally dehiscent. The valves (5 or) 6-8, are fusiform (rod shaped), splitting from apex and base and remaining attached by woody persistent placental strips. The styles are caducous. It has many seeds, which are arranged vertically in the capsule, they are winged with a broad wing,M. M. J. van Balgooy {{google books|29klAQAAMAAJ|Malesian Seed Plants: Portraits of tree families, (Rijksherbarium/Hortus Botanicus, 1997)|page=125}} which is flat, thin, triangular, squarish or rectangular, completely surrounding seed.
Taxonomy
The genus name of Itoa is in honour of Keisuke Itō (1803–1901) a Japanese physician and biologist, and his grandson Tokutarō Itō (1868–1941),{{cite book | last=Quattrocchi | first=Umberto | title=CRC World Dictionary of Plant Names, Volume II, D–L | publisher=CRC Press | location=Boca Raton, Florida | year=2000 | isbn=978-0-8493-2676-9}} and it was first described and published in Hooker's Icon. Pl. Vol.27 on table 2688 in 1901.
Known species
The following species are accepted by Plants of the World Online:{{Div col}}
- Itoa orientalis {{small|Hemsl.}}
- Itoa stapfii {{small|(Koord.) Sleumer}}{{small|}}{{small|}}{{small|}}{{small|}}{{small|}}{{small|}}{{small|}}{{small|}}{{small|}}{{small|}}{{small|}}{{small|}}{{small|}}{{small|}}{{small|}}{{small|}}{{small|}}{{small|}}{{small|}}{{small|}}{{small|}}{{small|}}{{small|}}{{small|}}{{small|}}{{small|}}{{small|}}{{small|}}{{small|}}{{small|}}{{small|}}{{small|}}
{{Div col end}}
References
{{Reflist}}
{{Wikispecies-inline|Itoa}}
{{Taxonbar|from=Q2029578}}