Xanthisma species

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Scientific Name Xanthisma spinulosum var. chihuahuanum (Machaeranthera pinnatifida var. chihuahuana) USDA PLANTS Symbol
Common Name Chihuahua Tansyaster ITIS Taxonomic Serial No.
Family Asteraceae (Sunflower) efloras.org Reference
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Description Habitat: Clay or rocky soils in washes, prairies and roadsides; desert environment.
Plant: Erect perennial 12 to 20 inches tall; multiple tangled stems from woody base.
Leaves: Numerous stem leaves, 1 to 3 inches long, lanceolate overall; margins entire or pinnatifid lobes with spines at lobe tips.
Inflorescence: Compound yellow flowers about 1 inch or less across; 14 to 60 rays and 30-plus yellow disk florets.
Bloom Period: Spring to fall.
Reference: www.americansouthwest.net and www.efloras.org.
Notes: Xanthisma spinulosum is a highly variable species with several variants, X. chihuahuanum being found in the Chihuahua desert (including portions of Big Bend). Some of the variations seem to occur in the leaves and the degree to which the margins are prickled, and the presence, or lack of, small spines on the phyllary tips.
Texas Status
Scientific Name Xanthisma texanum var. drummondii USDA PLANTS Symbol
Common Name Drummond's Sleepy-daisy ITIS Taxonomic Serial No.
Family Asteraceae (Sunflower) Flora of North America Ref.
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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.
Texas Status

© Tom Lebsack 2019