Mentzelia dispersa

S. Watson

Proc. Amer. Acad. Arts 11: 137. 1876.

Common names: Nada stickleaf bushy or Nevada blazingstar
Endemic
Basionym: Mentzelia albicaulis var. integrifolia S. Watson Botany (Fortieth Parallel), 114. 1871
Synonyms: M. dispersa var. compacta (A. Nelson) J. F. Macbride M. dispersa var. latifolia (Rydberg) J. F. Macbride M. dispersa var. obtusa Jepson M. pinetorum A. Heller
Treatment appears in FNA Volume 12. Treatment on page 536. Mentioned on page 531, 532, 534, 537, 541.

Plants wandlike or candelabra-form, 10–40 (–50) cm. Basal leaves persisting; petiole present or absent; blade elliptic to linear, margins usually dentate, sinuses extending less than 1/4 to midvein, or entire, rarely deeply lobed. Cauline leaves: petiole present or absent (proximal leaves), absent (distal leaves); blade elliptic to linear (proximal leaves), orbiculate to linear (distal leaves), to 10 cm, margins usually dentate, sinuses extending less than 1/4 to midvein, or entire, rarely deeply lobed. Bracts green, orbiculate to ovate, 2.1–6.5 × 1.1–3 mm, width 1/3–7/8 length, not concealing capsule, margins 3-lobed or entire. Flowers: sepals 1–3.5 mm; petals usually yellow, rarely orange, proximally, yellow distally, 2–6 (–8) mm, apex rounded; stamens 20–40, 2–4.5 mm, filaments monomorphic, filiform, unlobed; styles 2–3.5 (–5) mm. Capsules narrow-cylindric, 7–30 × 1–2.5 mm, axillary curved to 30° at maturity, usually inconspicuously longitudinally ribbed. Seeds 10–20, in 1 row distal to mid fruit, tan, dark-mottled or not, triangular prisms, surface ± smooth under 10× magnification; recurved flap over hilum absent; seed-coat cell outer periclinal wall flat. 2n = 18, 36, 72.


Phenology: Flowering (Apr–)May–Aug(–Sep).
Habitat: Loamy to sandy or rocky slopes, grasslands, scrub, dry forests, roadsides.
Elevation: 400–3100 m.

Distribution

V12 852-distribution-map.jpg

B.C., Ariz., Calif., Colo., Idaho, Mont., Nev., N.Dak., Oreg., S.Dak., Utah, Wash., Wyo.

Discussion

Mentzelia dispersa is the only polyploid species solely derived from the “Affines” clade and may be an autopolyploid complex (J. M. Brokaw and L. Hufford 2010, 2010b). Morphological characters that consistently distinguish cytotypes within M. dispersa have not been found. Mentzelia dispersa is most easily confused with M. affinis (see discussion under 65. M. affinis) but is phylogenetically distinct (Brokaw and Hufford 2010, 2010b).

Selected References

None.

Lower Taxa

None.

"not elongating" is not a number.

... more about "Mentzelia dispersa"
72 +, 36 +  and 18 +
monomorphic +
unlobed +  and filiform +
rounded +
Joshua M. Brokaw +
S. Watson +
not +  and persistent +
Mentzelia albicaulis var. integrifolia +
elliptic to linear +
orbiculate;linear +
0 cm0 mm <br />0 m <br /> (10 cm100 mm <br />0.1 m <br />) +
1/(1/3-7/8) +
0.21 cm2.1 mm <br />0.0021 m <br /> (0.65 cm6.5 mm <br />0.0065 m <br />) +
orbiculate;ovate +
0.11 cm1.1 mm <br />0.0011 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
0.7 cm7 mm <br />0.007 m <br /> (3 cm30 mm <br />0.03 m <br />) +
narrow-cylindric +
0.1 cm1 mm <br />0.001 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
Nada stickleaf +  and bushy or Nevada blazingstar +
B.C. +, Ariz. +, Calif. +, Colo. +, Idaho +, Mont. +, Nev. +, N.Dak. +, Oreg. +, S.Dak. +, Utah +, Wash. +  and Wyo. +
400–3100 m. +
curved +  and straight +
s--shaped +, clavate +, urceolate +, ovoid +, cylindric +, subcylindric +, lingulate +  and cup-shaped +
Loamy to sandy or rocky slopes, grasslands, scrub, dry forests, roadsides. +
free +  and adnate +
2-lobed +, unlobed +  and filiform +
cauline +  and basal +
entire +  and 3-lobed +
0 (?) +  and 1/4 (?) +
elliptic +  and linear +
apical +, subapical +  and inferior +
inconspicuous +
0.6 cm6 mm <br />0.006 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
yellow +  and orange +
connate +  and distinct +
spreading +  and erect +
hairy +  and glabrous +
obovate +, oblanceolate +, elliptic +, ovate +  and spatulate +
0.2 cm2 mm <br />0.002 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
Flowering (Apr–)May–Aug(–Sep). +
0 cm0 mm <br />0 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
Proc. Amer. Acad. Arts +
not +, dark-mottled +  and tan +
triangular +
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 +
0.1 cm1 mm <br />0.001 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
adnate +, free +  and distinct +
included +  and exserted +
20 +  and 40 +
0.2 cm2 mm <br />0.002 m <br /> (0.45 cm4.5 mm <br />0.0045 m <br />) +
decumbent +, clambering +  and erect +
papillate +
3-lobed +  and lingulate +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
0.2 cm2 mm <br />0.002 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
M. dispersa var. compacta +, M. dispersa var. latifolia +, M. dispersa var. obtusa +  and M. pinetorum +
Mentzelia dispersa +
Mentzelia sect. Trachyphytum +
species +
dendritic +  and unbranched +
straight +
40 cm400 mm <br />0.4 m <br /> (50 cm500 mm <br />0.5 m <br />) +
candelabra-form +  and wand-like +