Cosmos atrosanguineus

Cosmos atrosanguineus
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Eudicots
(unranked):	Asterids
Order:	Asterales
Family:	Asteraceae
Tribe:	Heliantheae
Genus:	Cosmos
Species:	C. atrosanguineus
Binomial name
Cosmos atrosanguineus (Hook.) Voss
Synonyms[1][2]
Bidens atrosanguinea Ortgies Cosmos diversifolius var. atrosanguineus Hook.

Cosmos atrosanguineus (Chocolate Cosmos) is a species of Cosmos, native to Mexico, where it is extinct in the wild. The species was introduced into cultivation in 1902, where it survives as a single clone reproduced by vegetative propagation. ^[3]

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 as the summer day wears on.

Cultivation and uses

The single surviving clone is a popular ornamental plant, grown for its rich dark red-brown flowers. It is not self-fertile, so no viable seeds are produced, and the plant has to be propagated by division of the tubers, or by tissue culture.^[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