Cosmos atrosanguineus (Hook.) Voss - Asteraceae - chocolate cosmos, Schokoladen-Kosmee

Perennial herb, up to 60cm high, native to Mexico; young vegetative and flowering shoots often with simple petiolate leaves, later leaves conspicuously pinnate; flowers solitary terminal, with usually 8 broad ray florets, dark red to maroon, 3-4cm in diam.

„Her scent, reminiscent of dark chocolate, unfolds in warm summer weather in the late afternoon hours.“
http://de.wikipedia.org/wiki/Schokoladen-Kosmee

„… a plant which has been proven to exist as one clone worldwide and one which is apparently sterile… This species has not been refound in the wild since it was last apparently collected in the 1860s… One significant character of the flowering plant, omitted in the scientific descriptions, that has led to the profusion of common names, is the rather intense smell of chocolate from the capitula. This makes the plant a special hit with chocoholics and adds an element of surprise when people are tempted to smell the capitula.It is somewhat reminiscent of plain dark chocolate, and although evident at most times it is particularly strong during the heat of the day and in to the evening. One website suggested that it had the smell of 'vanilla and hot chocolate', although I must admit I have not yet sensed the vanilla.“
[Plate 461. Cosmos Atrosanguineus Compositae., Hind, N., Fay, M.F., Curtis's Botanical Magazine, Vol.20(1), 2003, 40-48]

„Cosmos atrosanguineus is not extinct in the wild, a fact that was known as long ago as 1986 but which was never widely appreciated. It is also clear that while some plants, such as the one widely propagated by tissue culture, are male-sterile, many are male-fertile and seed-raised plants have been grown since 1990.“
[The story of Cosmos atrosanguineus, The Plantsman, June 2017]
https://www.rhs.org.uk/about-the-rhs/publications/magazines/the-plantsman/2017-Issues/June/the-story-of-cosmos-atrosanguineus.pdf

Curtis’s Botanical Magazine, vol.87 [ser.3, vol.17] t.5227 (1861) [W.H.Fitch]
http://plantgenera.org/species.php?id_species=278920

Cosmos atrosanguineus, CC BY-SA 3.0, Author: Sten Wikimedia Commons