Xanthocephalum gymnospermoides, San Pedro Matchweed
Scientific Name: Xanthocephalum gymnospermoides
Common Name: San Pedro Matchweed
Also Called: Gummy Broomweed, Gummy Snakeweed, Matchweed
Family: Asteraceae, Sunflower Family
Synonyms: (Grindelia gymnospermoides, Gutierrezia gymnospermoides)
Size: Up to 4 feet more or less.
Growth Form: Forb/herb; plants with single stem with multiple branches in upper sections; herbage glabrous.
Leaves: Green; leaves up to 4 inches long; mostly lanceolate; margins entire or with small spiny teeth; leaf surface viscid or resinous.
Flower Color: Yellow, golden yellow; showy flower heads with both disk and short ray flowers, flower heads glutinous; multiple flower heads on each branch; fruit an achene.
Flowering Season: August to October in Arizona and July or August to October elsewhere.
Elevation: 1,000 to 5,500 feet.
Habitat Preferences: Meadows, stream bottoms, ditches and alluvial or often saline soil.
Recorded Range: Xanthocephalum gymnospermoides is rare in the United States although locally common where it is found only in AZ, TX. In Arizona it is found in Santa Cruz County and in Texas no locations are disclosed. Possibility that this species is also found in southwest New Mexico. A known record for this species from: San Diego, California, San Elijo Lagoon Conservation Reserve.
This species is also present in northern Mexico.
North America & US County Distribution Map for Xanthocephalum gymnospermoides.
U.S. Weed Information: No information available.
Invasive/Noxious Weed Information: No information available.
Wetland Indicator: In North America Xanthocephalum gymnospermoides, San Pedro Matchweed has the following wetland designations: Lower 48 States, FACW; North America, FACW; Arid West, FAC.
FACW = Facultative Wetland, usually occur in wetlands, but may occur in non-wetlands
FAC = Facultative, occur in wetlands and non-wetlands
Threatened/Endangered Information: No information available.
In the Southwestern United States there is 1 species of Xanthocephalum. All data is approximate and subject to taxonomic changes.
Comments: Xanthocephalum gymnospermoides is rare in the United States found only in limited distribution in Arizona and Texas. The photos above are plants in Santa Cruz County, Arizona. Possibility that this species is also found in southwest New Mexico.
The type species for Xanthocephalum gymnospermoides is from between Babocomari, Arizona, and Santa Cruz, Sonora (Wright 1177)