Mentzelia torreyi
Mentzelia humilis
Torrey's blazing star
gypsum blazingstar
5–25 cm.
solitary or multiple, erect, straight;
branches distal or along entire stem, distal longest or all ± equal, antrorse; straight to upcurved; hairy.
petiole absent;
blade ovate or obovate, to 45 × 35 mm, intersinus distance 2–4 mm.
blade 25–95 × 5.5–28(–36.2) mm, widest intersinus distance 0.8–9.1 mm;
proximal spatulate to oblanceolate or elliptic, margins pinnate to pinnatisect, lobes 4–16(–20), slightly antrorse or perpendicular to leaf axis, 2.3–11.8(–16.4) mm;
distal elliptic, lanceolate, spatulate, or linear, base not clasping, margins entire or dentate to pinnatisect, teeth or lobes (0–)4–16, slightly antrorse or perpendicular to leaf axis, 2.3–13.8(–16.9) mm;
abaxial surface with simple grappling-hook, needlelike, and sometimes complex grappling-hook trichomes, adaxial surface with simple grappling-hook and needlelike trichomes.
margins usually entire, rarely pinnate.
0(–1.5) mm.
petals yellow to orange, narrowly spatulate to obovate, 4.5–17 × 1.2–5 mm, apex rounded;
stamens 25–45, 7–21 mm;
styles 7–18 mm.
petals white, 10.3–13(–28.6) × 1.4–4 mm, apex acute, glabrous abaxially;
stamens white, 5 outermost petaloid, filaments linear to narrowly spatulate, slightly clawed, 8.8–19(–22.3) × 0.7–3.3 mm, without anthers, second whorl without anthers;
anthers straight after dehiscence, epidermis papillate;
styles 6.5–11.3 mm.
3–7 × 3–4.5 mm.
cup-shaped, 5.3–10.2 × (4.2–)5.2–8.6 mm, base rounded, not longitudinally ridged.
3–9 per capsule, edges prominently to inconspicuously ridged.
coat anticlinal cell walls wavy, papillae 6–12 per cell.
= 28.
Mentzelia torreyi
Mentzelia humilis
Varieties 2 (2 in flora).
In the phylogenetic study by L. Hufford et al. (2003), Mentzelia torreyi was recovered as the sister to the rest of the genus.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Varieties 2 (2 in the flora).
The basionym of Mentzelia humilis is often cited as M. multiflora var. humilis A. Gray (1852). However, in that publication Gray indicated accepted names in Roman capitals (see ipni.org), whereas the varietal name is in lower case, indicating that he was using it as a descriptive term rather than a scientific name. Valid publication of the basionym thus must be attributed to Urban and Gilg.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Petals 8–17 mm, yellow; longest stamens to 1 mm longer than petals. | var. torreyi |
1. Petals 4.5–8 mm, orangish yellow, orange, or burnt orange; longest stamens usually much more than 1 mm longer than petals. | var. acerosa |
1. Leaf blade widest intersinus distances 0.8–2.6(–3.3) mm; lobes of proximal leaves 1–2.9 mm wide. | var. humilis |
1. Leaf blade widest intersinus distances 1.6–9.1 mm (always on some leaves greater than 2.6 mm); lobes of proximal leaves (1.1–)2.9–5.1 mm wide. | var. guadalupensis |
CA
PNW Herbaria
WildflowerSearch
iNaturalist
USDA Plants Database
