Arabis crucisetosa

Constance & Rollins

Proc. Biol. Soc. Wash. 49: 147. 1936.

Endemic
Treatment appears in FNA Volume 7. Treatment on page 262. Mentioned on page 258.

Perennials; (caudex usually simple, rarely branched, covered with persistent petiolar remains); sparsely to densely pubescent basally, trichomes short-stalked, cruciform or 3-rayed, stellate, (to 0.4 mm in diam.). Stems simple or few from caudex, erect, unbranched or rarely branched (few) distally, (1–) 1.5–4 (–5) dm, (glabrous throughout or sparsely pubescent proximally). Basal leaves: petiole 0.5–2.5 (–3) cm; blade oblanceolate to obovate, (0.6–) 1–3.5 (–4.5) cm × (3–) 5–15 (–20) mm, margins entire or dentate, (not ciliate), apex obtuse, surfaces uniformly pubescent, trichomes short-stalked, stellate. Cauline leaves 3 or 4 (–6); blade linear, oblong or oblanceolate, 1–3 (–4) cm × (1.5–) 3–7 (–10) mm, base cuneate, not auriculate, margins usually entire, rarely few-toothed, apex obtuse, surfaces glabrous or sparsely pubescent at least along margin. Racemes simple. Fruiting pedicels ascending to divaricate, (5–) 8–20 mm, (glabrous). Flowers: sepals (greenish), oblong, 2.5–4 × 1–1.5 mm, lateral pair saccate basally; petals white, oblanceolate, 7–9 × 2.5–3.5 mm, apex rounded; filaments 2.5–4 mm; anthers oblong, 0.8–1 mm; (gynophore to 0.5 mm). Fruits divaricate, slightly torulose, sometimes slightly curved, slightly flattened, (1.3–) 1.7–3.5 (–4) cm × 1–1.5 mm; valves each with obscure midvein extending to middle; ovules 14–28 per ovary; style 0.5–1.3 mm. Seeds not winged, oblong, 1–1.2 × 0.5–0.6 mm. 2n = 32.


Phenology: Flowering Apr–Jun.
Habitat: Open woods, rocky bluffs, steep banks, canyon margins
Elevation: 400-1800 m

Discussion

Arabis crucisetosa is known from Idaho, Lewis, and Nez Perce counties in Idaho, from Wallowa County in Oregon, and from Asotin County in Washington.

Selected References

None.

Lower Taxa

None.

"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 "Arabis crucisetosa"
0.08 cm0.8 mm <br />8.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
rounded +  and obtuse +
Ihsan A. Al-Shehbaz +
Constance & Rollins +
sessile +  and petiolate +
not auriculate +  and cuneate +
appendaged +  and unappendaged +
3 cm30 mm <br />0.03 m <br /> (4 cm40 mm <br />0.04 m <br />) +
0.7 cm7 mm <br />0.007 m <br /> (1 cm10 mm <br />0.01 m <br />) +
not +  and auriculate +
1 cm10 mm <br />0.01 m <br /> (3 cm30 mm <br />0.03 m <br />) +
lyrate-pinnatifid +, dentate to denticulate +  and entire +
dissected +, repand +, sinuate +, crenate +  and dentate +
oblanceolate;oblong;linear;oblanceolate;obovate +
much smaller +  and reduced +
0.3 cm3 mm <br />0.003 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
urceolate +, campanulate +  and tubular +
branched +  and simple +
petiolate +  and sessile +
well-developed +
distinct +
differentiated +
emarginate +  and entire +
Idaho +, Oreg. +  and Wash. +
400-1800 m +
straight +  and curved +
not winged +  and unappendaged +
connate +  and distinct +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
actinomorphic +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
0.1 cm1 mm <br />0.001 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
latiseptate +  and unsegmented +
3.5 cm35 mm <br />0.035 m <br /> (4 cm40 mm <br />0.04 m <br />) +
indehiscent +  and dehiscent +
1.7 cm17 mm <br />0.017 m <br /> (3.5 cm35 mm <br />0.035 m <br />) +
flattened +  and torulose +
0.1 cm1 mm <br />0.001 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
latiseptate +, stipitate +  and sessile +
flattened +  and torulose +
Open woods, rocky bluffs, steep banks, canyon margins +
annular +  and semiannular +
sessile +  and petiolate +
alternate +, not +  and rosulate +
cauline +  and basal +
connate +  and distinct +
decurrent +
entire +  and dentate +
few-toothed +
forked +
tenuinucellate +, crassinucellate +  and bitegmic +
campylotropous +  and anatropous +
rudimentary +
oblanceolate +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
2.5 cm25 mm <br />0.025 m <br /> (3 cm30 mm <br />0.03 m <br />) +
0.5 cm5 mm <br />0.005 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
Flowering Apr–Jun. +
trinucleate +  and 3(-11)-colpate +
Proc. Biol. Soc. Wash. +
0.5 cm5 mm <br />0.005 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
slender +
0.8 cm8 mm <br />0.008 m <br /> (2 cm20 mm <br />0.02 m <br />) +
mucilaginous +
uniseriate +  and biseriate +
not +  and mucilaginous +
white +, black +, brown +  and yellow +
0.1 cm1 mm <br />0.001 m <br /> (0.12 cm1.2 mm <br />0.0012 m <br />) +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.06 cm0.6 mm <br />6.0e-4 m <br />) +
not basally +  and saccate +
persistent +  and caducous +
distinct +
ascending +  and erect +
oblong +  and ovate +
reduced +
latiseptate +  and unsegmented +
indehiscent +  and dehiscent +
latiseptate +  and unsegmented +
indehiscent +  and dehiscent +
tetradynamous +
branched +, unbranched +  and simple +
procumbent +  and decumbent +
subsessile +, sessile +  and petiolate +
persistent +
distinct +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.13 cm1.3 mm <br />0.0013 m <br />) +
pubescent +  and glabrous +
Cruciferae +
Arabis crucisetosa +
species +
3-rayed +  and cruciform +
coiled +, 1-7-veined +  and veined +
anastomosing +
rhizomatous +, taprooted +, scapose +  and not +
perennial +, biennial +  and annual +
subshrub +  and herb +
aquatics +  and terrestrial +
glabrous +  and pubescent +