Mentzelia pectinata
Mentzelia dispersa
San Joaquin blazing star
bushy blazing-star, bushy mentzelia, Nada stickleaf, Nevada blazingstar, scattered blazing star
persisting;
petiole present or absent;
blade lanceolate to linear, margins deeply to shallowly lobed.
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.
petiole absent;
blade ovate to linear, to 12 cm, margins deeply lobed to dentate.
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.
green, ovate to lanceolate, 6.6–12.8 × 1.9–6.8 mm, width 1/5–2/3 length, not concealing capsule, margins 3–7-lobed.
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.
sepals 3–13 mm;
petals red to orange proximally, orange to yellow distally, 8–22 mm, apex mucronate, rounded, or retuse;
stamens 20+, 4–11 mm, filaments monomorphic, filiform, unlobed;
styles 5–13 mm.
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.
clavate, 12–35 × 2–4 mm, axillary curved to 90° at maturity, usually inconspicuously longitudinally ribbed.
narrow-cylindric, 7–30 × 1–2.5 mm, axillary curved to 30° at maturity, usually inconspicuously longitudinally ribbed.
20–40, in 2+ rows distal to mid fruit, tan, dark-mottled or not, usually irregularly polygonal, occasionally triangular prisms proximal to mid fruit, surface tuberculate under 10x magnification; recurved flap over hilum absent;
seed coat cell outer periclinal wall domed, domes on seed edges more than 1/2 as tall as wide at maturity.
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.
= 18.
= 18, 36, 72.
Mentzelia pectinata
Mentzelia dispersa
Mentzelia pectinata occurs in Kern, San Luis Obispo, Santa Barbara, and Tulare counties, around the southern rim of the San Joaquin Valley, extending into the Inner Coast Ranges and the southern foothills of the Sierra Nevada. Petal color varies from orange to yellow, and fully fertile artificial hybrids have been obtained between populations representing the extreme phenotypes (J. E. Zavortink 1966). Phylogenetic studies suggest that M. pectinata and M. congesta have hybridized to form several allopolyploid species (J. M. Brokaw and L. Hufford 2010b) despite their current allopatric distributions.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
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).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
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