Mentzelia hirsutissima

S. Watson

Proc. Amer. Acad. Arts 12: 252. 1877.

Common names: Hairy blazingstar
Synonyms: Mentzelia hirsutissima var. stenophylla (Urban & Gilg) I. M. Johnston Mentzelia stenophylla Urban & Gilg
Treatment appears in FNA Volume 12. Treatment on page 525. Mentioned on page 497, 524.

Plants (5–) 15–30 (–40) cm. Basal leaves: petioles present or absent; blade oblanceolate, to 11 cm; margins shallowly lobed, lobes rounded. Cauline leaves: petioles absent; blade ovate to lanceolate, to 11 cm, base often cordate-clasping, margins deeply to shallowly lobed, lobes acute. Bracts green, inconspicuous, not concealing pedicel, ovary, or capsule. Flowers: petals yellow to orange, obovate, 12–31 mm, apex mucronate; stamens 4–12 mm, less than 1/2 petal length, all fertile, none petaloid (flowers appearing to have 5 petals); filaments ±monomorphic, linear, most or all distally 2-lobed, lobes to 0.3 mm; anther stalk longer than filament lobes; style 6–15 mm. Capsules cylindric to cupshaped, 13–25 × 5–8 mm, erect. Seeds widest at middle, not grooved; seed-coat anticlinal cell-walls deeply wavy.


Phenology: Flowering Apr–May.
Habitat: Washes, fans, slopes, desert scrub.
Elevation: 0–800 m.

Distribution

V12 143-distribution-map.jpg

Calif., Mexico (Baja California), Mexico (Baja California Sur), Mexico (Sonora)

Discussion

Mentzelia hirsutissima is superficially similar to M. tricuspis and M. tridentata, but these taxa can be distinguished geographically. Mentzelia hirsutissima is distributed primarily on the Baja California Peninsula and occurs in California only in San Diego and far western Imperial counties, whereas M. tricuspis and M. tridentata occur north and east of this distribution. California populations previously have been called M. hirsutissima var. stenophylla. However, G. S. Daniels (1970) found that characters used to distinguish varieties of M. hirsutissima were not stable within populations.

Selected References

None.

Lower Taxa

None.

"not elongating" is not a number."widest" is not a number.

... more about "Mentzelia hirsutissima"
monomorphic +
1 (?) +  and 3 (?) +
2-lobed +
mucronate +
Joshua M. Brokaw +
S. Watson +
ovate;lanceolate +
0 cm0 mm <br />0 m <br /> (11 cm110 mm <br />0.11 m <br />) +
inconspicuous +
1.3 cm13 mm <br />0.013 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
cylindric +  and cupshaped +
0.5 cm5 mm <br />0.005 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
Hairy blazingstar +
Calif. +, Mexico (Baja California) +, Mexico (Baja California Sur) +  and Mexico (Sonora) +
0–800 m. +
curved +  and straight +
s--shaped +, clavate +, urceolate +, ovoid +, cylindric +, subcylindric +, lingulate +  and cup-shaped +
Washes, fans, slopes, desert scrub. +
free +  and adnate +
unlobed +, 2-lobed +  and linear +
cauline +  and basal +
acute +  and rounded +
apical +, subapical +  and inferior +
perpendicular +  and oriented +
inconspicuous +
yellow +  and orange +
connate +  and distinct +
spreading +  and erect +
hairy +  and glabrous +
obovate +
1.2 cm12 mm <br />0.012 m <br /> (3.1 cm31 mm <br />0.031 m <br />) +
Flowering Apr–May. +
0 cm0 mm <br />0 m <br /> (1 cm10 mm <br />0.01 m <br />) +
Proc. Amer. Acad. Arts +
not grooved +
flattened +, pyriform +  and ovoid +
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 +
adnate +, free +  and distinct +
included +  and exserted +
0 +  and 1/2 +
0.4 cm4 mm <br />0.004 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
decumbent +, clambering +  and erect +
papillate +
3-lobed +  and lingulate +
0.6 cm6 mm <br />0.006 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
Mentzelia hirsutissima var. stenophylla +  and Mentzelia stenophylla +
Mentzelia hirsutissima +
Mentzelia sect. Bicuspidaria +
species +
dendritic +  and unbranched +
straight +
30 cm300 mm <br />0.3 m <br /> (40 cm400 mm <br />0.4 m <br />) +