Mentzelia pectinata
Mentzelia packardiae
San Joaquin blazing star
Packard's blazingstar, Packard's mentzelia, Packard's stick-leaf
persisting;
petiole present or absent;
blade lanceolate to linear, margins deeply to shallowly lobed.
persisting or not.
petiole absent;
blade ovate to linear, to 12 cm, margins deeply lobed to dentate.
petiole present or absent (proximal leaves), absent (distal leaves);
blade lanceolate to linear (proximal leaves), ovate to linear (distal leaves), to 10(–14) cm, margins dentate or entire (proximal leaves), entire (distal leaves).
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, ovate to elliptic, 4.3–8.3 × 1.9–3.2 mm, width 1/3–2/3 length, not concealing capsule, margins 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 4–10 mm;
petals orange proximally, yellow distally, 10–20 mm, apex rounded to retuse;
stamens 20+, 4–13 mm, filaments monomorphic, filiform, unlobed;
styles 6–14 mm.
clavate, 12–35 × 2–4 mm, axillary curved to 90° at maturity, usually inconspicuously longitudinally ribbed.
narrow-cylindric, 8–35 × 2.5–4 mm, axillary curved to 45° at maturity, often prominently 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 to minutely tessellate under 10x magnification; recurved flap over hilum absent;
seed coat cell outer periclinal wall flat to slightly convex.
= 18.
= 72.
Mentzelia pectinata
Mentzelia packardiae
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 packardiae is the most narrowly distributed species in sect. Trachyphytum, known only from the Leslie Gulch area in eastern Malheur County. During most years, M. packardiae is predominantly limited to barren, ash-derived gravel slopes. A reported collection from Elko County, Nevada, is most likely from a large-flowered population of M. dispersa (N. H. Holmgren et al. 2005). Mentzelia packardiae can be distinguished from M. dispersa by its larger flowers with longer petals [10–20 mm versus 2–6(–8) mm] and styles [6–14 mm versus 2–3.5(–5) mm], and its wider capsules (2.5–4 mm versus 1–2.5 mm).
Mentzelia packardiae is listed as threatened by the Oregon Department of Agriculture and is in the Center for Plant Conservation’s National Collection of Endangered Plants.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
CA
WildflowerSearch
iNaturalist
USDA Plants Database
OR
Flora NW
PNW Herbaria
