Cosmos bipinnatus

File:Cosmea_2_-_24.08.2007.jpg

Cosmos bipinnatus is an annual that is often considered half-hardy, although plants may reappear via self-sowing for several years. The plant height varies from 2–6 ft to (rarely) 9 ft ({{convert|2|-|6|-|9|ft|abbr=on|disp=out}}). The cultivated varieties appear in shades of pink and purple as well as white. The branched stem is usually densely to occasionally occupied by fine, split up, rough trichomes, but some specimens are completely hairless. The petiole itself is inconspicuous, winged, 10 (rarely to 15) mm long, and sometimes the leaves are almost sessile.

The partial leaves are linear-filiform to narrow linear with a width of 0.5 to 1 (rarely to 1.7) mm; the tips are pointed, hardened, but not particularly sharp. Its foliage appears as if finely cut into threadlike segments. When flowering, the plants can become top heavy. This problem is alleviated when they are grown in groups, as the bipinnate leaves interlock and the plants support each other.

The achenes become blackish, are smooth or short-bristly. Their shape is spindle-like. They are rounded off into a short, 0.5 to 1.7 mm long, but distinctly pronounced rostrum. The inner achenes are up to 18 mm long, their yellowish beaks are 4 to 5 (rarely to 10) mm long. A pappus is missing or it consists only of two to three awn-like, 1-3 mm large bristles.Erich Oberdorfer : Plant sociology excursion flora for Germany and adjacent areas. In collaboration with Angelika Schwabe and Theo Müller. 8th, heavily revised and supplemented edition. Eugen Ulmer, Stuttgart (Hohenheim) 2001, {{ISBN|3-8001-3131-5}}, p 929

File:Cosmos bipinnatus flowers in Sivas, Turkey.jpg, Turkey]]

The very conspicuous cup-shaped inflorescences have a diameter of usually {{cvt|5-7|cm|in|abbr=on}} and contain tongue and tubular flowers, which are surrounded by bracts. There are usually 8 outer bracts, and they are ovate to lanceolate-tail-shaped, 7-15 mm long, 3-5 mm wide. The inner bracts are ovate-lanceolate and 8-12 mm long. They are translucent with many black stripes and a clear edge up to 1 mm wide, sometimes with yellowish or pink pigments, the tip is ciliate. The sprout leaves have gold-yellow, thread-like tips and protrude between the tubular flowers. The broadened base of these spreader leaves is translucent, with a yellow line.

The mostly eight ray florets are pink to violet or white colored, at the base may show noticeable stains caused by anthocyanin. The tongues are reversely ovate shaped, have a length of usually 20-35 mm and a width of usually 12-20 mm. The tips are almost dull and have three broad, wavy teeth. Below that, they are greatly rejuvenated. In the center of the flower baskets is a large number of tubular flowers (also called disc florets), whose overgrown petals are yellow, turn white in the lower part and reach a length of 5-6 mm. The anthers are brownish-black and about 3 mm long, at the tips are short-triangular, translucent attachments with a length of 0.5-0.8 mm. The branches of the stylus are short and rather dull, with a length of .5 mm.Thomas E. Melchert Cosmos bipinnatus. In: Dorothy L. Nash, Louis O. Williams (ed.): Flora of Guatemala. In: Fieldiana: Botany. Volume 24, Part XII, 1976, pp. 230-231.

This plant is native to Mexico, Guatemala and Costa Rica. Since it is used as an ornamental plant in many countries and prone to sedimentation{{clarification needed|date=July 2024}}, it is an invasive plant in many areas of the world. It has naturalized in scattered locations across North America, South America, the West Indies, Italy, Australia, and Asia, where it is a garden escape (introduced species) and in some habitats becoming a weed.[http://bonap.net/MapGallery/County/Cosmos%20bipinnatus.png Biota of North America Program 2014 county distribution map]

Cultivars of Cosmos bipinnatus in cultivation today are listed here. Those marked {{smallcaps|agm}} have gained the Royal Horticultural Society's Award of Garden Merit.

• Apollo Series
• 'Apollo Carmine' {{smallcaps|agm}}{{cite web | url = https://www.rhs.org.uk/Plants/353834/Cosmos-bipinnatus-Apollo-Carmine-(Apollo-Series)/Details | title = "Cosmos bipinnatus" 'Apollo Carmine' | publisher = RHS | accessdate = 5 May 2020}}
• 'Apollo Pink' {{smallcaps|agm}}{{cite web | url = https://www.rhs.org.uk/Plants/353833/Cosmos-bipinnatus-Apollo-Pink-(Apollo-Series)/Details | title = "Cosmos bipinnatus" 'Apollo Pink' | publisher = RHS | accessdate = 12 April 2020}}
• 'Apollo White' {{smallcaps|agm}}{{cite web | url = https://www.rhs.org.uk/Plants/353832/Cosmos-bipinnatus-Apollo-White-(Apollo-Series)/Details | title = "Cosmos bipinnatus" 'Apollo White' | publisher = RHS | accessdate = 5 May 2020}}
• 'Daydream'{{cite web | url = https://www.rhs.org.uk/Plants/133327/Cosmos-bipinnatus-Daydream/Details

| title = "Cosmos bipinnatus" 'Daydream' | publisher = RHS | accessdate = 5 May 2020}} features a pink inner ring on a white background

• Double Click Series{{cite web | url = https://www.rhs.org.uk/Plants/235171/Cosmos-bipinnatus-Double-Click-Series-(d)/Details

| title = "Cosmos bipinnatus" Double Click Series | publisher = RHS | accessdate = 5 May 2020}} features semidouble to fully double flowers that resemble Japanese anemones (Anemone japonica)

• 'Double Click Cranberries'{{cite web | url = https://www.rhs.org.uk/Plants/323048/Cosmos-bipinnatus-Double-Click-Cranberries-(Double-Click-Series)-(d)/Details | title = "Cosmos bipinnatus" 'Double Click Cranberries' | publisher = RHS | accessdate = 5 May 2020}}
• 'Double Click Rose Bonbon'{{cite web | url = https://www.rhs.org.uk/Plants/353848/Cosmos-bipinnatus-Double-Click-Rose-Bonbon-(Double-Click-Series)-(d)/Details | title = Double Click Rose Bonbon | publisher = RHS | accessdate = 5 May 2020}}
• 'Double Click Snow Puff'{{cite web | url = https://www.rhs.org.uk/Plants/294465/Cosmos-bipinnatus-Double-Click-Snow-Puff-(Double-Click-Series)-(d)/Details | title = "Cosmos bipinnatus" 'Double Click Snow Puff' | publisher = RHS | accessdate = 5 May 2020}}
• 'Double Click Vari Extra'{{cite web | url = https://www.rhs.org.uk/Plants/353865/Cosmos-bipinnatus-Double-Click-Vari-Extra-(Double-Click-Series)-(d)/Details | title = "Cosmos bipinnatus" 'Double Click Vari Extra' | publisher = RHS | accessdate = 5 May 2020}}
• 'Rubenza' {{smallcaps|agm}}{{cite web | url = https://www.rhs.org.uk/Plants/282033/Cosmos-bipinnatus-Rubenza/Details

| title = "Cosmos bipinnatus" 'Rubenza' | publisher = RHS | accessdate = 5 May 2020}}

• 'Sensation', also known as 'Early Sensation', is a widely available mix of tall varieties
• 'Sensation Pinkie' {{smallcaps|agm}}{{cite web | url = https://www.rhs.org.uk/Plants/149039/Cosmos-bipinnatus-Sensation-Pinkie-(Sensation-Series)/Details | title = "Cosmos bipinnatus" 'Sensation Pinkie' | publisher = RHS | accessdate = 5 May 2020}}
• Sonata series{{cite web | url = https://www.rhs.org.uk/Plants/142768/Cosmos-bipinnatus-Sonata-Series/Details

| title = "Cosmos bipinnatus" Sonata Series | publisher = RHS | accessdate = 5 May 2020}}

• 'Velouette' {{smallcaps|agm}}{{cite web | url = https://www.rhs.org.uk/Plants/353861/Cosmos-bipinnatus-Velouette/Details

| title = "Cosmos bipinnatus" 'Velouette' | publisher = RHS | accessdate = 5 May 2020}}

• 'Versailles', developed for the cut flower trade, are shorter than others of the species, with heights remaining below three feet
• 'Versailles Dark Rose'{{cite web | url = https://www.rhs.org.uk/Plants/354173/Cosmos-bipinnatus-Versailles-Dark-Rose/Details

| title = "Cosmos bipinnatus" 'Versailles Dark Rose' | publisher = RHS | accessdate = 5 May 2020}}

• 'Versailles Tetra'{{cite web | url = https://www.rhs.org.uk/Plants/132450/Cosmos-bipinnatus-Versailles-Tetra-(Versailles-Series)/Details | title = Cosmos bipinnatus 'Versailles Tetra' (Versailles Series) | cosmea 'Versailles Tetra'/RHS Gardening| publisher = RHS | accessdate = 5 May 2020}}

Growth characteristics of this plant include:

• Germination takes between 7 and 10 days at the optimal temperature of {{convert|75|F|0}}; flowering begins between 60 and 90 days after germination
• It prefers a soil pH between 6.0 and 8.5, reflecting its native habitat in the alkaline regions of Central America
• Flowering is best in full sun, although partial shade is tolerated

Excessive rain can cause cultivation problems, due to the delicate nature of the stems. Heavy rain can cause breakage. Cosmos bipinnatus can tolerate heat as long as adequate moisture is provided, however, it does not handle droughts, strong winds or cold temperatures well. Snails, slugs and aphids have a taste for Cosmos bipinnatus. Successfully cultivated plants can mature {{convert|2 to 4|ft}} x {{convert|12 to 18|in}}.

• They are not tolerant of frost, but can be grown outdoors in a temperate climate with a warm to hot summer and are therefore called half-hardy in British gardening literature.{{cite book |last1=Negus |first1=John |title=The Flower Garden |date=1986 |publisher=Octopus Books Ltd. |location=London |pages=31, 33 |url=https://archive.org/details/flowergarden0000unse_g6t8/page/30 |access-date=14 October 2023}}

The flowers of Cosmos bipinnatus attract birds and butterflies,{{cite book|author1=Bruce Asakawa|author2=Sharon Asakawa|title=California Gardener's Guide|url=https://archive.org/details/brucesharonasaka00asak|url-access=registration|accessdate=25 November 2011|date=3 September 2001|publisher=Cool Springs Press|isbn=978-1-930604-47-6|pages=[https://archive.org/details/brucesharonasaka00asak/page/26 26]–27}} including the monarch butterfly. It can be part of butterfly gardening and pollinator/honey-bee habitat gardens.

file:Cosmos bipinnatus7.jpg|Typical range of colours in a dense stand

file:Cosmos bipinnatus 'Double Click' Leaves 1600px.jpg

file:Cosmos bipinnatus flower bud.jpg

file:Cosmos_bipinnatus_(5).jpg

file:Cosmos bipinnatus 09 ies.jpg|alt=Detail of florets

file:Cosmos bipinnatus 10 ies.jpg|Lateral aspect|alt=Detail, lateral aspect

file:Seeds of Cosmos bipinnatus 2012.08.13 15-52-05.jpg|Seeds

file:Schmuckkörbchen mit Biene.jpg

file:Cosmos bipinnatus (Asteraceae) with an Andrena sp. bee.jpg |Andrena sp. pollinating

File:Pink cosmos 03481.jpg

File:R10_kamera_049be.jpg

File:大波斯菊 20190926161741 09.jpg

File:White Cosmos Bipinnatus.jpg

{{Reflist}}

• [http://plantanswers.tamu.edu/flowers/cosmos/cosmos.html Cosmos history and cultivation, Texas A&M University]
• [https://web.archive.org/web/20071215031014/http://www.cordobes.com/30dias/noticia13.html Cosmos Festival in Argentina] - Press and video
• Jepson Manual Treatment - [http://ucjeps.berkeley.edu/cgi-bin/get_JM_treatment.pl?609,1020,1021 Jepson Manual, University of California, Cosmos bipinnatus]
• [https://plants.usda.gov/java/profile?symbol=COBI2 United States Department of Agriculture Plants Profile]
• [http://calphotos.berkeley.edu/cgi/img_query?query_src=photos_index&where-taxon=Cosmos+bipinnatus Cosmos bipinnatus] - Calphotos Photo gallery, University of California

{{Taxonbar|from=Q575748}}

bipinnatus

Category:Flora of Mexico

Category:Garden plants of North America

Category:Butterfly food plants

Category:Annual plants

Category:Plants described in 1791

Category:Taxa named by Antonio José Cavanilles