Xanthisma species [Asteraceae]

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Scientific Name Xanthisma spinulosum var. chihuahuanum (Machaeranthera pinnatifida var. chihuahuana) USDA PLANTS Symbol MAPIC
Common Name Chihuahua Tansyaster ITIS Taxonomic Serial No. 780983
Family Asteraceae (Sunflower) Flora of North America Ref. Click Here
Description Habitat: Clay or rocky soils in washes, prairies and roadsides; desert environment.
Plant: Erect perennial 12 to 20 inches tall; multiple tangled smooth or slightly hairy stems from woody base.
Leaves: Numerous stem leaves, usually somewhat hairy, 1 to 3 inches long; lower leaves lanceolate overall, pinnatifid lobes with spines at lobe tips, central portion much wider than lobes; upper leaves with few or no lobes, becoming linear-oblong, tips rounded with short spines.
Inflorescence: Terminal, compound yellow flowers about 1 inch or less across; 14 to 60 rays and 30-plus yellow disk florets; phyllary tips not bent and without a spine.
Bloom Period: Spring to fall.
References: Machaeranthera pinnatifida in "Manual of the Vascular Plants of Texas" by Correll and Johnston, www.americansouthwest.net and Flora of North America.
Notes: Xanthisma spinulosum is a highly variable species with several variants, chihuahuanum being found in the Chihuahua desert (including portions of Big Bend). 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.
BONAP Distribution Map

Texas Status:
Native
Scientific Name Xanthisma spinulosum var. spinulosum (Machaeranthera texensis) USDA PLANTS Symbol MATE12
Common Name Lacy Tansyaster, Spiny Goldenweed ITIS Taxonomic Serial No. 780987
Family Asteraceae (Sunflower) SEINet
Reference
Click Here
Description Habitat: Sandy, rocky soils in plains and hillsides, washes and along roadsides.
Plant: Erect perennial 12 to 20 inches tall, stout hairy branches from woody base.
Leaves: Numerous 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: Machaeranthera texensis in "Manual of the Vascular Plants of Texas" by Correll and Johnston, www.americansouthwest.net and Flora of North America.
Notes: Xanthisma spinulosum is a highly variable species with several variants, spinulosum being found from Alberta, the Great Plains, Texas to northern Mexico.
BONAP Distribution Map

Texas Status:
Native
Scientific Name Xanthisma texanum var. drummondii USDA PLANTS Symbol XATED
Common Name Drummond's Sleepy-daisy ITIS Taxonomic Serial No. 541813
Family Asteraceae (Sunflower) Flora of North America Ref. Click Here
Description Habitat: Dry, open areas in prairies, meadows, pastures.
Plant: Erect annual, 8 inches to 3 feet tall (or more), 1 to 3 stems branching in the upper half.
Leaves: Basal leaves 2 to 3-1/8 inches long, deeply pinnately-lobed; stem leaves alternate, stalkless and somewhat glossy, 1/2 to 2 inches long; lower oblanceolate overall with dentate or shallowly pinnately-lobed edges, upper lanceolate to linear and margins entire.
Inflorescence: Compound yellow flowers 3/4 to 1-1/2 inch across; 12 to 34 rays with pointed tips and 50 to 200+ yellow disk florets.
Bloom Period: May to September.
References: "Wildflowers of the Texas Hill Country" by Marshall Enquist, "Manual of the Vascular Plants of Texas" by Correll and Johnston and Flora of North America.
Notes: X. texanum closes at night and cloudy days, hence its common name.
BONAP Distribution Map

Texas Status:
Native

© Tom Lebsack 2019