Cosmos atrosanguineus

Classification System: APG IV

Superregnum: Eukaryota
Regnum: Plantae
Cladus: Angiosperms
Cladus: Eudicots
Cladus: Core eudicots
Cladus: Asterids
Cladus: Campanulids
Ordo: Asterales

Familia: Asteraceae
Subfamilia: Asteroideae
Tribus: Coreopsideae
Genus: Cosmos
Sectio: C. sect. Discopoda
Species: Cosmos atrosanguineus
Name

Cosmos atrosanguineus (Hook.) Voss
Synonyms

Bidens atrosanguinea Ortg. ex Regel
Cosmos diversifolius var. atrosanguineus Hook. in Curtis

Distribution
Native distribution areas:
References

Voss, Vilmorin's Illustrierte Blumengartnerei ed. 3, 1: 485. 1894.

Links

International Plant Names Index. 2017. Cosmos atrosanguineus. Published online. Accessed: Dec. 27 2017.
The Plant List 2013. Cosmos atrosanguineus in The Plant List Version 1.1. Published online. Accessed: 2017 Dec. 27.
Tropicos.org 2017. Cosmos atrosanguineus. Missouri Botanical Garden. Published online. Accessed: 27 Dec. 2017.
Hassler, M. 2017. Cosmos atrosanguineus. World Plants: Synonymic Checklists of the Vascular Plants of the World In: Roskovh, Y., Abucay, L., Orrell, T., Nicolson, D., Bailly, N., Kirk, P., Bourgoin, T., DeWalt, R.E., Decock, W., De Wever, A., Nieukerken, E. van, Zarucchi, J. & Penev, L., eds. 2017. Species 2000 & ITIS Catalogue of Life. Published online. Accessed: 2017 Dec 27. Reference page.
USDA, ARS, Germplasm Resources Information Network. Cosmos atrosanguineus (Hook.) Voss in the Germplasm Resources Information Network (GRIN), U.S. Department of Agriculture Agricultural Research Service. Accessed: 07-Oct-06.
Cosmos atrosanguineus – Taxon details on National Center for Biotechnology Information (NCBI).
EOL: Cosmos atrosanguineus

Vernacular names
Deutsch: Schokoladen-Kosmee
English: Chocolate Cosmos
日本語: ベニコスモス
한국어: 초콜릿코스모스
中文: 巧克力秋英

Cosmos atrosanguineus, the chocolate cosmos, is a species of Cosmos, native to Mexico. It has often been claimed that it is extinct in the wild; however it is "quite abundant" in Mexico. The species was introduced into cultivation in 1885, when the British seed company Thompson & Morgan first listed it in their seed catalogue.[4] Its dark red to brownish red flowers have a scent resembling chocolate, which is one reason for its popularity as a cultivated plant.

Description

Cosmos atrosanguineus is a herbaceous perennial plant growing to 40–60 cm tall, with a fleshy tuberous root. The leaves are 7–15 cm long, pinnate, with leaflets 2–5 cm long. The flowers are produced in a capitulum 3–4.5 cm diameter, dark red to maroon-dark brown, with a ring of six to ten (usually eight) broad ray florets and a center of disc florets; they have a light vanillin fragrance (like many chocolates), which becomes more noticeable towards the end of the day.[5]
Taxonomy

The species was first described in 1861 by William Hooker, as Cosmos diversifolia var. atrosanguineus. Eduard Ortgies later elevated it to a full species, placing it in the genus Bidens. Andreas Voss transferred it back to Cosmos, retaining its status as an independent species. It is one of eight species of Cosmos placed in section Discopoda. Cosmos belongs to subtribe Coreopsidinae.[4]

In 2008, Oku, T.; Takahashi, H.; Yagi, F.; et al. analyzed the Chocolate Cosmos flower using PSID (plastid subtype identity) sequences in order to clarify the phylogenetic relationships of this plant. They determined that this species did indeed have closer relations to Cosmos than to the genus of Bidens or Dahlia.
Distribution and habitat

Although it had been reported that Cosmos atrosanguineus was extinct in the wild, a research project on the genus Cosmos begun in 2007 by Mexican botanist Aarón Rodríguez found modern records starting from 1986. Field work showed that it grew in the states of Guanajuato, Querétaro and San Luis Potosí. It is found in mixed pine and oak forest, at elevations of around 1,800–2,450 m (5,910–8,040 ft).[4]
Cultivation and uses

Both seed-raised and vegetatively propagated cultivars are available, varying in the size, colour and shape of the petals. An article in 2017 listed 17 cultivars and seed-raised strains. As of 2018, C. atrosanguineus 'Hamcoec' (trade description Eclipse) has the largest flower heads, up to 5 cm in diameter.[4] The variation in flower color from red to black of Cosmos atrosanguineus and its cultivars results from variation in the amounts of anthocyanins and chalcone present.[6] Hybrids with other Cosmos species are also known in cultivation. As with Cosmos 'Thomocha' (Chocamocha), hybrids may be less scented than the species.[4]

It requires partial sun or full sun, and flowers from mid to late summer. It is frost-sensitive (Zones 6–11); in temperate zones, the tuber has to be dug up and stored in a frost-free store over the winter.
References

"Plant Name Details for Cosmos atrosanguineus (Hook.) Voss", The International Plant Names Index, retrieved 2018-05-28
Tropicos
The Plant List
Rice, Graham (2017), "The story of Cosmos atrosanguineus", The Plantsman, New Series, 16 (2): 112–119
"Plants that make the mouth water". 22 February 2009.

Amamiya, K., & Iwashina, T. (2016). "Qualitative and Quantitative Analysis of Flower Pigments in Chocolate Cosmos, Cosmos atrosanguineus, and its Hybrids". Natural Product Communications, 11(1), 77–78.

7. Oku, T. ; Takahashi, H. ; Yagi, F.; Nakamura, I. ; Mii, M. (2008). "Hybridisation between chocolate cosmos and yellow cosmos confirmed by phylogenetic analysis using plastid subtype identity (PSID) sequences" JOURNAL OF HORTICULTURAL SCIENCE & BIOTECHNOLOGY, 83 (3), 323-327