Mentzelia packardiae
Mentzelia tridentata
Packard's blazingstar, Packard's mentzelia, Packard's stick-leaf
creamy blazing star, dentate blazing star, threetooth blazingstar
persisting or not.
petioles present;
blade lanceolate, to 9 cm;
margins shallowly lobed, lobes rounded.
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).
petioles present, rarely absent, present in distalmost leaves;
blade broadly ovate to lanceolate, to 9 cm, base not cordate-clasping, margins dentate to serrate.
green, ovate to elliptic, 4.3–8.3 × 1.9–3.2 mm, width 1/3–2/3 length, not concealing capsule, margins entire.
green, inconspicuous, not concealing pedicel, ovary, or capsule.
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.
petals white to pale yellow, obovate, 10–40 mm, apex mucronate;
stamens 6–15 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 0.1–0.7 mm;
anther stalk longer than or equal to filament lobes;
style 9–13 mm.
narrow-cylindric, 8–35 × 2.5–4 mm, axillary curved to 45° at maturity, often prominently longitudinally ribbed.
cylindric to ovoid, 9–18 × 5–8 mm, basal nodding, distal erect.
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.
widest at middle, not grooved;
seed coat anticlinal cell walls straight or wavy.
= 72.
= 20.
Mentzelia packardiae
Mentzelia tridentata
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.)
Mentzelia tridentata is known from the central and western Mojave Desert in Inyo, Kern, and San Bernardino counties. See 55. M. tricuspis for comparison with M. tridentata.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
OR
Flora NW
PNW Herbaria
WildflowerSearch
iNaturalist
USDA Plants Database
CA
