Data provided by the participants of the Consortium of California Herbaria

View additional distribution information on the Jepson eflora

Madia exigua is a species of flowering plant in the aster family known by the common names small tarweed and threadstem madia. It is native to western North America from British Columbia to Baja California, where it grows in many types of dry habitat outside the deserts. It is an aromatic annual herb growing up to half a meter tall, its slender stem coated with hairs, large stalked resin glands, and sometimes bristles. The rough-haired leaves are 1 to 4 centimeters long. The flower cluster 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 flower cluster 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.

Plant type

Annual herb

Size

2 ft Tall

Calscape icon
Color

Yellow

Sun

Full Sun, Partial Shade

Site type

Grassy places, open woodland

Plant communities

Woodland

Bees
Caterpillars
Butterflies

Butterflies and moths supported

0 confirmed and 3 likely

Confirmed Likely

Epiblema deverrae

Spotted Straw Sun Moth

Heliothis phloxiphaga

Small Heliothodes Moth

Heliothodes diminutivus