Streptanthus brachiatus

F. W. Hoffman

Madroño 11: 230, fig. 5. 1952.

EndemicConservation concern
Synonyms: Streptanthus brachiatus subsp. hoffmanii R. W. Dolan & LaPré
Treatment appears in FNA Volume 7. Treatment on page 706. Mentioned on page 703, 723.

Biennials; (somewhat glaucous), glabrous throughout. Stems usually branched basally, rarely unbranched, 1.4–5 (–6) dm. Basal leaves (soon withered); rosulate; shortly petiolate; blade (fleshy, mottled), broadly obovate to suborbicular, 1.5–4 cm, margins coarsely dentate. Cauline leaves: blade ovate to cordate, 0.7–3.7cm × 3–15 mm (smaller distally), base auriculate to amplexicaul, margins serrate-dentate or entire. Racemes ebracteate, (lax, sometimes secund). Fruiting pedicels divaricate-ascending, (straight), 1–2 mm. Flowers: calyx urceolate; sepals (erect), rose-purple (to yellowish at base), (ovate), 5–7 mm, keeled, (apex recurved); petals whitish, (abaxial pair with purple spot, adaxial pair faintly purple-veined), 7–10 mm, blade 1.5–3 × 1–1.5 mm, margins not crisped, claw 5–7 mm, as wide as or wider than blade; stamens in 3 unequal pairs; filaments: abaxial pair (connate to middle), 4–7 mm, lateral pair 2–4 mm, adaxial pair (completely connate, usually recurved), 8–10 mm; anthers: abaxial and lateral pairs fertile, 2–2.5 mm, adaxial pair sterile, 0.7–1.2 mm; gynophore 0.3–0.7 mm. Fruits divaricate-ascending, torulose, nearly straight, flattened, 4–6 cm × 1–1.3 mm; valves each with obscure midvein; replum constricted between seeds; ovules 22–30 per ovary; style 0.1–0.4 mm; stigma subentire. Seeds oblong, 1.8–2.5 × 0.7–0.9 mm; wing 0–0.1 mm wide distally. 2n = 28.


Phenology: Flowering Jun–Jul.
Habitat: Serpentine barrens in chaparral, pine-oak or cypress woodland openings
Elevation: 600-1000 m

Discussion

Of conservation concern.

Streptanthus brachiatus is known from Lake and Sonoma counties. At the time that R. W. Dolan and L. F. LaPré (1989) studied it, infraspecific taxa based on differences in sepal color and pubescence seemed distinct (R. E. Buck et al. 1993). Populations discovered since then do not accord with the putative differences.

Selected References

None.

Lower Taxa

None.

No values specified."elongated" is not a number."thick" is not a number."dm" is not declared as a valid unit of measurement for this property."dm" is not declared as a valid unit of measurement for this property.

... more about "Streptanthus brachiatus"
0.2 cm2 mm <br />0.002 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
0.07 cm0.7 mm <br />7.0e-4 m <br /> (0.12 cm1.2 mm <br />0.0012 m <br />) +
lateral +  and abaxial +
linear +  and oblong +
0.2 cm2 mm <br />0.002 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
Ihsan A. Al-Shehbaz +
F. W. Hoffman +
auriculate to amplexicaul +
appendaged +  and unappendaged +
not +  and auriculate +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
lyrate-pinnatifid +, dentate +  and entire +
dissected +, repand +, sinuate +, crenate +  and dentate +
ovate;cordate +
much smaller +  and reduced +
1.5 cm15 mm <br />0.015 m <br /> (4 cm40 mm <br />0.04 m <br />) +
urceolate +
branched +  and simple +
petiolate +  and sessile +
well-developed +
distinct +
0.5 cm5 mm <br />0.005 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
differentiated +
emarginate +  and entire +
600-1000 m +
straight +  and curved +
not winged +  and unappendaged +
connate +  and distinct +
zygomorphic +  and actinomorphic +
rose-purple +
0.5 cm5 mm <br />0.005 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
latiseptate +, stipitate +  and subsessile +
straight +
4 cm40 mm <br />0.04 m <br /> (6 cm60 mm <br />0.06 m <br />) +
divaricate-ascending +
flattened +  and torulose +
0.1 cm1 mm <br />0.001 m <br /> (0.13 cm1.3 mm <br />0.0013 m <br />) +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (0.07 cm0.7 mm <br />7.0e-4 m <br />) +
Serpentine barrens in chaparral, pine-oak or cypress woodland openings +
sessile +  and petiolate +
alternate +, not +  and rosulate +
cauline +  and basal +
connate +  and distinct +
decurrent +
entire +, serrate-dentate +  and dentate +
not crisped +
tenuinucellate +, crassinucellate +  and bitegmic +
campylotropous +  and anatropous +
unequal +
rudimentary +
oblong +  and ovate +
0.7 cm7 mm <br />0.007 m <br /> (1 cm10 mm <br />0.01 m <br />) +
Flowering Jun–Jul. +
trinucleate +  and 3(-11)-colpate +
divaricate-ascending +
stout +  and slender +
0.1 cm1 mm <br />0.001 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
constricted +
mucilaginous +
aseriate +, uniseriate +  and biseriate +
not +  and mucilaginous +
white +, black +, brown +  and yellow +
0.18 cm1.8 mm <br />0.0018 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
0.07 cm0.7 mm <br />7.0e-4 m <br /> (0.09 cm0.9 mm <br />9.0e-4 m <br />) +
persistent +  and caducous +
distinct +
reduced +
latiseptate +, schizocarpic +, samaroid +  and lomentaceous +
indehiscent +  and dehiscent +
angustiseptate +, flat +, angled +, terete +, torulose +, not +, segmented +  and nutletlike +
Endemic +  and Conservation concern +
tetradynamous +
unbranched +  and branched +
procumbent +  and decumbent +
ascending +  and erect +
subentire +
subsessile +, sessile +  and petiolate +
persistent +
distinct +
0.01 cm0.1 mm <br />1.0e-4 m <br /> (0.04 cm0.4 mm <br />4.0e-4 m <br />) +
Streptanthus brachiatus subsp. hoffmanii +
Streptanthus brachiatus +
Streptanthus +
species +
dendritic +  and simple +
coiled +, 1-7-veined +  and veined +
pubescent +  and glabrous +
anastomosing +
perennial +, biennial +  and annual +
subshrub +  and shrub +
aquatics +  and terrestrial +
glabrous +  and pubescent +
0mm;0.1mm +