Mentzelia pectinata
Mentzelia lagarosa
San Joaquin blazing star
slender-lobed blazingstar
solitary, erect, straight;
branches distal, distal longest, antrorse, straight; hairy.
blade 11.3–103 × 4.8–20.1 mm, widest intersinus distance 1.2–5.7 mm;
proximal oblanceolate to elliptic, margins pinnate to pinnatisect, lobes 8–20, slightly antrorse or perpendicular to leaf axis, 1.4–8.2 mm;
distal elliptic to lanceolate, base not clasping, margins pinnatisect, lobes 6–16, slightly antrorse or perpendicular to leaf axis, 1.6–7.5 mm;
abaxial surface with simple grappling-hook, complex grappling-hook, and occasionally needlelike trichomes, adaxial surface with simple grappling-hook and needlelike trichomes.
persisting;
petiole present or absent;
blade lanceolate to linear, margins deeply to shallowly lobed.
petiole absent;
blade ovate to linear, to 12 cm, margins deeply lobed to dentate.
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.
margins usually entire, sometimes toothed or pinnate.
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.
petals golden yellow, 8.3–13 × 2.2–5.4 mm, apex acute or rounded, glabrous abaxially;
stamens golden yellow, 5 outermost petaloid, filaments narrowly spatulate, slightly clawed, 6.5–10.7 × 1.7–4.3 mm, without anthers, second whorl with anthers;
anthers straight after dehiscence, epidermis smooth;
styles 6.1–10.2 mm.
clavate, 12–35 × 2–4 mm, axillary curved to 90° at maturity, usually inconspicuously longitudinally ribbed.
cylindric, 12.1–21.2 × 4.9–7.6 mm, base tapering or rounded, not longitudinally ridged.
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.
coat anticlinal cell walls wavy, papillae 29–31 per cell.
= 18.
= 22.
Mentzelia pectinata
Mentzelia lagarosa
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 lagarosa is allopatric with two of the three species most similar to it, namely M. holmgreniorum and M. filifolia, and nearly allopatric with the third, M. laciniata. Where the ranges of M. lagarosa and M. laciniata overlap in western Colorado, they can be distinguished by petal length [8.3–13 mm in M. lagarosa versus 14–23.8(–26) mm in M. laciniata], outermost stamen length (6.5–10.7 mm in M. lagarosa versus 12–20 mm in M. laciniata), and number of seed coat cell papillae (29–31 per cell in M. lagarosa versus 5–14 per cell in M. laciniata); in addition, M. lagarosa bears both simple grappling-hook and needlelike trichomes on its adaxial leaf blade surfaces, whereas leaf blades of M. laciniata bear only needlelike trichomes adaxially. In the Intermountain Flora, N. H. Holmgren et al. (2005) treated M. lagarosa as a synonym of M. multiflora, but J. J. Schenk and L. Hufford (2011) showed not only that M. lagarosa is distinct from M. multiflora, but also that the latter does not occur in the intermountain region.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
CA
WildflowerSearch
iNaturalist
USDA Plants Database
