E-Flora BC: Electronic Atlas of the Flora of British Columbia

Mentzelia albicaulis (Hook.) Torr. & A. Gray
small-flowered evening star (whitestem blazingstar; white-stemmed evening star)
Loasaceae (Loasa family)

Introduction to Vascular Plants

© Virginia Skilton  Email the photographer   (Photo ID #14231)

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Distribution of Mentzelia albicaulis
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Species Information

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Annual herb from a taproot; stems erect, several, simple or branched, white-shiny, usually somewhat barbed throughout, sometimes becoming glabrous, 10-40 cm tall.
Basal leaves, oblanceolate, deeply pinnatifid with deeply notched lobes, 2-11 cm long; stem leaves alternate, linear to lanceolate, 2-11 cm long, lobed or unlobed, wider, unstalked and entire to few-toothed above.
Inflorescence of few, stalked flowers in a tight, terminal cluster; petals 5, yellow, 2-6 mm long; calyces 1-2 cm long, hairy, the lobes 2-4 mm long; stamens shorter than the petals; bracts narrow to broadly lanceolate.
Capsules, narrowly club-shaped, 1-2.5 cm long; seeds 15-30, conspicuously rough-pimply under 10x magnification, not flattened.
Difficult to separate from M. dispersa unless seeds are available.

Source: The Illustrated Flora of British Columbia

Habitat / Range

Dry sand or clay banks in the steppe zone; locally frequent in SC BC; S to MT, NM, AZ and CA.

Source: The Illustrated Flora of British Columbia


Ecological Framework for Mentzelia albicaulis

The table below shows the species-specific information calculated from
original data (BEC database) provided by the BC Ministry of Forests and Range.
(Updated August, 2013)

Site Information
Value / Class




Elevation (metres) 335 540 766
Slope Gradient (%) 0 45 75
Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]
111 168 271
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
1 1 2
Modal Nutrient Regime
Number of field plots
 species was recorded in:
Modal BEC Zone Class
All BEC Zones (# of stations/zone) species was recorded in: BG(5), IDF(1), PP(1)


The climate type for this species, as reported in the: "British Columbia plant species codes and selected attributes. Version 6 Database" (Meidinger et al. 2008), is not evaluated, unknown or variable.

Synonyms and Alternate Names

Acrolasia albicaulis (Hook.) Rydb.
Acrolasia gracilis Rydb.
Mentzelia albicaulis var. ctenophora (Rydb.) H. St. John
Mentzelia albicaulis var. gracilis (Rydb.) J. Darl.
Mentzelia albicaulis var. tenerrima (Rydb.) H. St. John
Mentzelia albicaulis var. veatchiana (Kellogg) Urb. & Gilg
Mentzelia gracilenta var. veatchiana (Kellogg) Urb. & Gilg
Mentzelia gracilis (Rydb.) H.J. Thomp. & F.H. Lewis, non Urb. & Gilg
Mentzelia mojavensis H.J. Thomp. & Roberts
Trachyphytum gracile Nutt., nom. inval.

Taxonomic and Nomenclatural Links

Additional Photo Sources

General References