small-flowered evening star (whitestem blazingstar; white-stemmed evening star)
Loasaceae (Loasa family)
Introduction to Vascular Plants
Species Information
General:
Annual herb from a taproot; stems erect, several, simple or branched, white-shiny, usually somewhat barbed throughout, sometimes becoming glabrous, 10-40 cm tall.
Leaves:
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.
Flowers:
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.
Fruits:
Capsules, narrowly club-shaped, 1-2.5 cm long; seeds 15-30, conspicuously rough-pimply under 10x magnification, not flattened.
Notes:
Difficult to separate from M. dispersa unless seeds are available.
Illustration
If more than one illustration is available for a species (e.g., separate illustrations were provided for two subspecies) then links to the separate images will be provided below. Note that individual subspecies or varietal illustrations are not always available.
Illustration Source: The Illustrated Flora of British Columbia
Ecology
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 |
||
|
Avg |
Min |
Max |
|
| Elevation
(metres) |
540 | 335 | 766 |
| Slope
Gradient (%) |
45 | 0 | 75 |
|
Aspect (degrees) |
168 | 111 | 271 |
| Soil
Moisture Regime (SMR) [0 - very xeric; 4 - mesic; 8 - hydric] |
1 | 1 | 2 |
| Modal
Nutrient Regime
Class |
A | ||
| #
of field plots species was recorded in: |
7 | ||
| Modal
BEC Zone Class |
BG | ||
|
All BEC Zones (# of stations/zone) species was recorded in |
BG(5), IDF(1), PP(1) | ||
|
Source:
Klinkenberg 2013
|
|||
Habitat and Range
Dry sand or clay banks in the steppe zone; locally frequent in SC BC; S to MT, NM, AZ and CA.Status Information
Synonyms
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 Keys
1. Plants biennials or perennials; seeds flattened...........................M. laevicaulis
1. Plants annuals; seeds not flattened. 2. Basal leaves linear to shallowly lobed; seeds obscurely rough-pimply and apparently smooth 10X magnification; flower bracts mostly egg-shaped to narrowly egg-shaped; inflorescence congested............................M. dispersa 2. Basal leaves oblanceolate, deeply pinnatifid with deeply notched lobes; seeds conspicuously rough-pimply under 10X magnification; flower bracts narrowly to broadly lanceolate; inflorescence not congested.......................M. albicaulis Source: Illustrated Flora of British Columbia |