Madia exigua

Madia exigua
Scientific classification
Kingdom: Plantae
(unranked): Angiosperms
(unranked): Eudicots
(unranked): Asterids
Order: Asterales
Family: Asteraceae
Genus: Madia
Species: M. exigua
Binomial name
Madia exigua
(Sm.) A.Gray

Madia exigua is a species of flowering plant in the aster family known by the common names small tarweed and threadstem madia.

Range

Madia exigua is native to western North America from British Columbia to Baja California, where it grows in many types of dry habitat outside the deserts.

Description

Madia exigua is an aromatic annual herb growing up to half a meter (20") tall, its slender stem coated with hairs, large stalked resin glands, and sometimes bristles. The rough-haired leaves are 1 to 4 centimeters (0.4 to 1.6") long.

The inflorescence is an array of clustered flower heads on thin, stiff peduncles. Each head has an involucre of phyllaries shaped like a top. The phyllaries are coated in knobby yellow resin glands. At the tip of the inflorescence are minute yellowish ray florets each under a millimeter long, and one or two yellow disc florets. The fruit is an achene with no pappus.

Wikimedia Commons has media related to Madia exigua.


This article is issued from Wikipedia - version of the 11/20/2014. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.