Xanthisma spinulosum var. glaberrimum

(Rydberg) D. R. Morgan & R. L. Hartman

Sida 20: 1408. 2003.

Basionym: Sideranthus glaberrimus Rydberg Bull. Torrey Bot. Club 27: 621. 1900
Synonyms: Haplopappus spinulosus subsp. glaberrimus (Rydberg) H. M. Hall Haplopappus spinulosus var. glaberrimus (Rydberg) S. F. Blake Machaeranthera pinnatifida var. glaberrima (Rydberg) B. L. Turner & R. L. Hartman Xanthisma glaberrimum
Treatment appears in FNA Volume 20. Treatment on page 392. Mentioned on page 391.
Revision as of 20:31, 16 December 2019 by FNA>Volume Importer

Perennials, 20–50 cm, often woody at base. Stems stiffly erect, branched in distal 1/3; mid internodes 2–5 mm. Leaves numerous, strictly ascending, not reduced distally, margins pinnatifid, lobes oblong-lanceolate to triangular, 2–7 mm, faces usually glabrous, sometimes lightly tomentose, eglandular. Heads 2–10+, (subsesssile) usually clustered. Peduncles relatively terminal and lateral, 0.5–2 cm. Involucres 8–15 mm wide. 2n = 8, 16.


Phenology: Flowering spring–fall.
Habitat: Sandy to gravelly prairies, hillsides, and roadsides
Elevation: 800–1400 m

Distribution

V20-892-distribution-map.gif

Colo., Iowa, Kans., Nebr., N.Mex., N.Dak., Okla., Tex., Wyo.

Discussion

G. L. Nesom (2003) recognized Xanthisma spinulosum var. glaberrium at species level, as it occurs sympatrically with variety spinulosum in the Texas panhandle, where the two taxa behave like biological species; on the eastern plains of Colorado, however, hybridization and autoploidy have been documented (D. P. Hauber 1986).

Selected References

None.

Lower Taxa

None.
Ronald L. Hartman +
(Rydberg) D. R. Morgan & R. L. Hartman +
Sideranthus glaberrimus +
Colo. +, Iowa +, Kans. +, Nebr. +, N.Mex. +, N.Dak. +, Okla. +, Tex. +  and Wyo. +
800–1400 m +
Sandy to gravelly prairies, hillsides, and roadsides +
Flowering spring–fall. +
Haplopappus spinulosus subsp. glaberrimus +, Haplopappus spinulosus var. glaberrimus +, Machaeranthera pinnatifida var. glaberrima +  and Xanthisma glaberrimum +
Xanthisma spinulosum var. glaberrimum +
Xanthisma spinulosum +
variety +