Two people stand on a grassy hillside in the King Range Wilderness, overlooking the Pacific Ocean.
BLM
U.S. DEPARTMENT OF THE INTERIOR
BUREAU OF LAND MANAGEMENT
California Poppies Headwaters Forest Reserve Kayaker enjoying the California Coastal National Monument Headwaters Forest Reserve King Range National Conservation Area
California
BLM>California>Arcata>Noxious Weeds>Noxious Weeds Program
Print Page
Arcata Field Office

Mountain Tarweed (Madia glomerata)

Sunflower family (Asteraceae)


Description: Mountain tarweed is an annual herb about 5.7-31 inches (1.5-8 decimeters) tall and strongly ill-scented.  Its lower stems are soft-hairy to ±bristly and its upper stems have yellow, stalked glands. Mountain tarweed leaves are 0.8-3.7 inches (2-10 centimeters) long, mostly attached along the stem and often in axillary clusters, upper leaves glandular. Blooms are in panicle-like clusters with individual flowers heads about .2-.35 inches (5.5-9 millimeters) wide.

Habitat: Native to western North America, this species has been spreading and has become naturalized in many areas. It occurs in forest openings, as well as in the margins between forest and grassland. It has a tendency to grow aggressively and outcompetes grasses. It occurs at elevations between 1050-2700 feet (320 - 822 meters). Although this plant is a native, and not on many noxious weed lists, many local landowners regard it as a noxious weed.

Distribution: Throughout northern California in the above habitats.

Flowering Period: May through August