|Scientific Name||Xanthisma spinulosum var. spinulosum (Machaeranthera texensis)||USDA PLANTS Symbol||MATE12|
|Common Name||Spiny Goldenweed, Lacy Tansyaster||ITIS Taxonomic Serial No.||780987|
|Description||Habitat: Sandy, rocky soils in plains and hillsides, washes and along roadsides.
Plant: Spreading to sprawling perennial 4 to 16 inches tall, hairy stems usually much branched in lower 2/3; rarely woody at base.
Leaves: Numerous equally-spaced, spreading stem leaves, pinnately-lobed with median portion nearly the same width as lobes, each lobe with a sharp spine (mucronate); leaves 1 to 3 inches long overall.
Inflorescence: Terminal, compound yellow flowers about 1 inch or less across; 14 to 60 rays and 30-plus yellow disk florets; involucre is hemispherical in shape, tips of phyllaries bent with a small spine.
Bloom Period: Spring to fall.
References: American Southwest, Flora of North America and Machaeranthera texensis in "Manual of the Vascular Plants of Texas" by Correll and Johnston.
Notes: Xanthisma spinulosum is a highly variable species with several variants, var. spinulosum being found from Alberta, the Great Plains, Texas to northern Mexico. Some of the variations occur in the leaves and the degree to which the margins are lobed, and the presence, or lack of, small spines on the phyllary tips. There are also many synonyms.
|BONAP Distribution Map
Map Color Key
Banner photo of Lupinus ssp. by Rick Capozza, Austin TX
© Tom Lebsack 2023