Mentzelia decapetala
Mentzelia holmgreniorum
10-petal western star, evening starflower, gumbo-lily, tenpetal blazingstar
Holmgrens' blazingstar
solitary, erect, straight;
branches distal or along entire stem, proximal or distal longest, antrorse, straight to upcurved; hairy.
solitary, erect, straight;
branches distal or along entire stem, distal or proximal longest, antrorse, upcurved; hairy.
blade 72–295 × 14–45 mm, widest intersinus distance 10.1–23.3 mm;
proximal oblanceolate or elliptic, margins serrate to pinnate, teeth or lobes 16–26, slightly antrorse, 1–16.5 mm;
distal elliptic to lanceolate, base clasping or not, margins serrate to pinnate, teeth or lobes 9–20, slightly antrorse, 5.3–13.7 mm;
surfaces with needlelike trichomes.
blade 42–89 × 11–31.9 mm, widest intersinus distance 2.3–3.6 mm;
proximal oblanceolate to elliptic, margins pinnatisect, lobes 14–20, strongly antrorse, 4.9–14.4 mm;
distal lanceolate, base not clasping, margins pinnatisect, lobes 12–18, strongly antrorse, 4.2–12.4 mm;
abaxial surface with simple grappling-hook, complex grappling-hook, and needlelike trichomes, adaxial surface with simple grappling-hook and needlelike trichomes.
margins pinnate.
margins pinnate.
petals white, 47–75 × 13–22.7 mm, apex acute to attenuate, glabrous abaxially;
stamens white to yellow, 5 outermost petaloid, filaments spatulate, strongly clawed, 48–75 × 12–23 mm, without anthers, second whorl with anthers;
anthers straight after dehiscence, epidermis smooth;
styles 36–53 mm.
petals golden yellow, 13.5–18.8 × 5.2–6.6 mm, apex rounded, glabrous abaxially;
stamens golden yellow, 5 outermost petaloid, filaments narrowly spatulate, slightly clawed, 11.1–16 × 2.7–5 mm, without anthers, second whorl with anthers;
anthers straight after dehiscence, epidermis smooth;
styles 8.4–10.6 mm.
cylindric, 30–43 × 12–17 mm, base tapering, not longitudinally ridged.
cylindric, 13.1–14.6 × 5.8–6.9 mm, base tapering, not longitudinally ridged.
2.3–4 mm;
coat anticlinal cell walls straight, papillae 4–10 per cell.
coat anticlinal cell walls sinuous, papillae 26–51 per cell.
= 22.
= 20.
Mentzelia decapetala
Mentzelia holmgreniorum
Mentzelia decapetala is introduced in Grundy County, Illinois. It appears to be native throughout the rest of its distribution.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Mentzelia holmgreniorum is known from Apache, Coconino, and Navajo counties, Arizona, and Catron County, New Mexico. It is allopatric from the species most similar to it (M. filifolia, M. laciniata, and M. lagarosa), occurring south and west of all three; it differs from all these species in having upcurved rather than straight branches, and from M. filifolia and M. laciniata in having both simple grappling-hook and needlelike trichomes (versus only needlelike trichomes) on its adaxial leaf surfaces. In addition, M. holmgreniorum differs from M. filifolia in having leaf blades with greater intersinus distances (2.3–3.6 mm versus 1–2.4 mm) and wider lobes (1.6–2.5 mm versus 0.8–1.4 mm), from M. laciniata in having pinnate bracts (versus usually entire, rarely pinnate), and from M. lagarosa in having leaf blade lobes that are strongly antrorsely oriented (versus slightly antrorsely or perpendicular to the leaf axis) and flowers with larger petals (13.5–18.8 × 5.2–6.6 mm versus 8.3–13 × 2.2–5.4 mm) and longer outermost stamens (11.1–16 mm versus 6.5–10.7 mm).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
IL Wildflowers
KS Wildflowers
MN Wildflowers
PNW Herbaria
WildflowerSearch
iNaturalist
USDA Plants Database
