Mentzelia mollis

M. Peck

Leafl. W. Bot. 4: 183. 1945.

Common names: Smooth or soft blazingstar
EndemicConservation concern
Treatment appears in FNA Volume 12. Treatment on page 539. Mentioned on page 532.

Plants candelabra-form, 3–15 (–20) cm. Basal leaves not persisting. Cauline leaves: petiole present (proximal leaves), absent (distal leaves); blade lanceolate to linear (proximal leaves), ovate to lanceolate (distal leaves), to 6 cm, margins dentate or entire (proximal leaves), entire (distal leaves). Bracts green, ovate to elliptic, 5–8.5 × 2–5 mm, width 2/5–3/5 length, not concealing capsule, margins entire. Flowers: sepals 3–5.5 mm; petals yellow to orange proximally, yellow distally, 8–12 mm, apex rounded; stamens 20+, 3–8 mm, filaments monomorphic, filiform, unlobed; styles 7–9 mm. Capsules cylindric or clavate, 5–22 × 2–4 mm, axillary curved to 45° at maturity, often prominently longitudinally ribbed. Seeds 15–25, in 2+ rows distal to mid fruit, tan, dark-mottled, irregularly polygonal, surface smooth to minutely tessellate under 10× magnification; recurved flap over hilum absent; seed-coat cell outer periclinal wall flat to slightly convex. 2n = 36.


Phenology: Flowering Apr–Jul.
Habitat: Barren, sodic or calcic clay slopes and bluffs derived from volcanic ash.
Elevation: 800–1500 m.

Discussion

Mentzelia mollis is narrowly distributed in eastern Malheur County, Oregon, and western Owyhee County, Idaho, and disjunctly in the Black Rock Range of Humboldt County, Nevada. Recent phylogenetic studies support treatment of these disjunct populations as a single species (J. M. Brokaw and L. Hufford 2010b). In both ranges, M. mollis is predominantly limited to barren soils with high salinity. Mentzelia mollis is listed as endangered by the Oregon Department of Agriculture and is in the Center for Plant Conservation’s National Collection of Endangered Plants.

Selected References

None.

Lower Taxa

None.

"not elongating" is not a number.

... more about "Mentzelia mollis"
monomorphic +
unlobed +  and filiform +
rounded +
Joshua M. Brokaw +
M. Peck +
not persisting +
not +  and persistent +
Mentzelia +
lanceolate;linear ovate +
0 cm0 mm <br />0 m <br /> (6 cm60 mm <br />0.06 m <br />) +
1/(2/5-3/5) +
0.5 cm5 mm <br />0.005 m <br /> (0.85 cm8.5 mm <br />0.0085 m <br />) +
ovate;elliptic +
0.2 cm2 mm <br />0.002 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
0.5 cm5 mm <br />0.005 m <br /> (2.2 cm22 mm <br />0.022 m <br />) +
clavate +  and cylindric +
0.2 cm2 mm <br />0.002 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
Smooth or soft blazingstar +
Idaho +, Nev. +  and Oreg. +
800–1500 m. +
curved +  and straight +
s--shaped +, clavate +, urceolate +, ovoid +, cylindric +, subcylindric +, lingulate +  and cup-shaped +
Barren, sodic or calcic clay slopes and bluffs derived from volcanic ash. +
free +  and adnate +
2-lobed +, unlobed +  and filiform +
cauline +  and basal +
entire +  and dentate +
flat +  and slightly convex +
elliptic +  and linear +
apical +, subapical +  and inferior +
inconspicuous +
yellow +  and orange proximally +
connate +  and distinct +
spreading +  and erect +
hairy +  and glabrous +
obovate +, oblanceolate +, elliptic +, ovate +  and spatulate +
0.8 cm8 mm <br />0.008 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
Flowering Apr–Jul. +
0 cm0 mm <br />0 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
Leafl. W. Bot. +
dark-mottled +  and tan +
polygonal +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.45 cm4.5 mm <br />0.0045 m <br />) +
persistent +
lanceolate +  and narrowly ovate +
0.3 cm3 mm <br />0.003 m <br /> (0.55 cm5.5 mm <br />0.0055 m <br />) +
Endemic +  and Conservation concern +
adnate +, free +  and distinct +
included +  and exserted +
8 +  and 45 +
0.3 cm3 mm <br />0.003 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
decumbent +, clambering +  and erect +
papillate +
3-lobed +  and lingulate +
0.7 cm7 mm <br />0.007 m <br /> (0.9 cm9 mm <br />0.009 m <br />) +
smooth +  and minutely tessellate +
Mentzelia mollis +
Mentzelia sect. Trachyphytum +
species +
dendritic +  and unbranched +
straight +
15 cm150 mm <br />0.15 m <br /> (20 cm200 mm <br />0.2 m <br />) +