Mentzelia affinis
Mentzelia marginata
yellow comet
Colorado blazingstar
solitary, erect, straight;
branches mostly distal, proximal longer than distal, all usually extending to near the distal end of plant, antrorse, straight; hairy.
blade 22–115 × 2.8–10.9(–17.2) mm, widest intersinus distance 2.2–7(–9) mm;
proximal oblanceolate, elliptic, or lanceolate, margins dentate, teeth 10–24(–38), perpendicular to leaf axis, 0.5–4 mm;
distal elliptic to lanceolate, base not clasping, margins dentate, teeth 8–20, perpendicular to leaf axis, 0.3–5.6 mm;
abaxial surface with simple grappling-hook, complex grappling-hook, and usually with needlelike trichomes, adaxial surface with simple grappling-hook and needlelike trichomes.
persisting;
petiole present or absent;
blade linear-lanceolate to linear, margins usually deeply to moderately lobed, sinuses extending 1/4+ to midvein, rarely entire.
petiole absent;
blade ovate-lanceolate to lanceolate, to 17 cm, margins usually dentate or entire, rarely deeply lobed.
green, ovate to lanceolate, 2.7–6.6 × 0.9–2.1 mm, width 1/5–1/3 length, not concealing capsule, margins 3-lobed or entire.
margins entire.
sepals 1–7 mm;
petals yellow to orange proximally, yellow distally, 4–12 mm, apex acute;
stamens 20+, 3–6.5 mm, filaments monomorphic, filiform, unlobed;
styles 3–6.5 mm.
petals golden yellow, 8–14.4 × 2.1–3.9 mm, apex acute, hairy abaxially;
stamens golden yellow, 5 outermost petaloid, filaments narrowly spatulate, slightly clawed, 5.5–11.1 × 1.2–2.9 mm, with anthers, second whorl with anthers;
anthers straight after dehiscence, epidermis papillate;
styles 5.3–10 mm.
narrowly cylindric, 7–32 × 1–3 mm, axillary curved to 90° at maturity, often prominently longitudinally ribbed.
cylindric, 7–14.6 × 3.5–6.7 mm, base tapering, not longitudinally ridged.
10–20, in 1 row distal to mid fruit, tan, dark-mottled or not, triangular prisms, surface ±smooth under 10x magnification; recurved flap over hilum absent;
seed coat cell outer periclinal wall flat.
coat anticlinal cell walls straight to slightly wavy, papillae 4–10 per cell.
= 18.
= 20.
Mentzelia affinis
Mentzelia marginata
Herbarium specimens of Mentzelia affinis are often difficult to distinguish from those of M. dispersa despite distinct evolutionary histories (J. M. Brokaw and L. Hufford 2010). Several characters, including flower size, leaf margins, and capsule surfaces, differ substantially between these species, but habitat is the most dependable diagnostic character. Verified populations of M. affinis have not been found above 1200 meters in desert habitats, and grassland populations are usually restricted to much lower elevations. Sympatric populations of M. affinis and M. dispersa have not been found, and, in areas of range overlap in southern California, M. dispersa has not been found below 1200 meters or in desert vegetation.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Mentzelia marginata occurs on the western edge of Colorado in Delta, Garfield, Mesa, and Montrose counties. Reports of this species from Utah are based on specimens treated here as M. cronquistii.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
CA
WildflowerSearch
iNaturalist
USDA Plants Database
