Bidens heterosperma


Bidens heterosperma, commonly known as the Rocky Mountain beggarticks, is an annual or perennial, herbaceous, flowering plant in the family Asteraceae, tribe Coreopsideae. It is native to northwestern and north-central Mexico, and portions of the southwestern United States.

Description

Bidens heterosperma is an annual or perennial, herbaceous, flowering plant that grows between tall. The leaves are opposite, and are attached to petioles that are between 0.3 and 2 cm long; The leaf blades are once or twice pinnately divided, the terminal lobe is linear or filiform and is between 0.2 and 2.5 cm long by 0.5 to 2 cm wide; the leaves sometimes have small, hair-like protrusions on the margins; It usually produces flower heads one at a time on peduncles 1–10 cm long in groups of 5–6. The involucres are cylindric. There are 5–6 lanceolate to lance-elliptic phyllaries. There are 0–3 ray florets with yellow petals, and 5–13 disk florets with yellow corollas.
The plant flowers from September to October.

Distribution and habitat

Bidens heterosperma is native to Mexico and portions of the Southwestern United States.

Habitat

The plant typically grows on seeps on rocky slopes at elevations of from sea level.

Conservation

, the conversation organization NatureServe listed Bidens heterosperma as Secure (G5) worldwide. Individual states have not been ranked. This status was last reviewed on 2 June 1993.

Taxonomy

Bidens heterosperma was first named by Asa Gray in 1853 in the Smithsonian Contributions to Knowledge, volume 5 journal. The species has no listed synonyms in Plants of the World Online, World Flora Online, and Tropicos databases.

Etymology

According to SEINet, the species epithet heterosperma means "different seed". In English, the species is commonly called the Rocky Mountain Beggerticks.