Boechera cusickii

(S. Watson) Al-Shehbaz

Novon 13: 384. 2003.

Basionym: Arabis cusickii S. Watson Proc. Amer. Acad. Arts 17: 363. 1882
Treatment appears in FNA Volume 7. Treatment on page 372. Mentioned on page 353, 363, 377.

Perennials; long-lived; (often cespitose); sexual; caudex usually woody. Stems usually 1 per caudex branch, arising from center of rosette near ground surface, 1–2.5 (–3.8) dm, densely pubescent proximally, trichomes simple, 0.5–1.5 mm, sparsely pubescent or glabrous distally. Basal leaves: blade linear to narrowly oblanceolate, 0.5–2 mm wide, margins entire, ciliate, trichomes (simple), 1–1.7 mm, surfaces moderately pubescent, trichomes simple and long-stalked, 2-rayed, 0.5–1.7 mm. Cauline leaves: 10–30, often concealing stem proximally; blade auricles 0–0.5 mm, surfaces of distalmost leaves sparsely pubescent. Racemes 5–14-flowered, usually unbranched. Fruiting pedicels ascending, straight, 4–15 (–20) mm, glabrous or sparsely pubescent, trichomes simple. Flowers ascending at anthesis; sepals pubescent; petals white to lavender, 6–10 × 2–3 mm, glabrous; pollen ellipsoid. Fruits ascending to divaricate-ascending, not appressed to rachis, not secund, straight or curved, edges parallel, 4–8 (–9.5) cm × 2.3–3 mm; valves glabrous; ovules 56–106 per ovary; style 0.1–0.5 mm. Seeds uniseriate, 1.5–2.5 × 1.5–2 mm; wing continuous, 0.1–0.2 mm wide distally.


Phenology: Flowering Apr-mid May.
Habitat: Basaltic bluffs, rocky slopes, rock crevices, gravelly hillsides, sagebrush hills, outcrops of volcanic rock
Elevation: 600-1800 m

Discussion

Peripheral populations of Boechera cusickii in south-central Idaho and northern Nevada have a higher proportion of branched hairs, possibly resulting from hybridization with B. sparsiflora.

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.

... more about "Boechera cusickii"
oblong +  and ovate +
Ihsan A. Al-Shehbaz +  and Michael D. Windham +
(S. Watson) Al-Shehbaz +
not +  and rosulate +
Arabis cusickii +
appendaged +  and unappendaged +
0 cm0 mm <br />0 m <br /> (0.05 cm0.5 mm <br />5.0e-4 m <br />) +
lyrate-pinnatifid +, dentate +  and entire +
dissected +, repand +, sinuate +, crenate +  and dentate +
linear;narrowly oblanceolate +
much smaller +  and reduced +
0.5mm;2mm +
urceolate +, campanulate +  and tubular +
branched +  and simple +
petiolate +  and sessile +
well-developed +
indistinct +
not +  and differentiated +
emarginate +  and entire +
Idaho +, Nev. +, Oreg. +  and Wash. +
8 cm80 mm <br />0.08 m <br /> (9.5 cm95 mm <br />0.095 m <br />) +
4 cm40 mm <br />0.04 m <br /> (8 cm80 mm <br />0.08 m <br />) +
0.23 cm2.3 mm <br />0.0023 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
600-1800 m +
straight +  and curved +
not winged +  and unappendaged +
connate +  and distinct +
actinomorphic +
curved +  and straight +
ascending +  and divaricate-ascending +
torulose +, falcate +, lanceolate +, oblong +  and linear +
Basaltic bluffs, rocky slopes, rock crevices, gravelly hillsides, sagebrush hills, outcrops of volcanic rock +
annular +  and semiannular +
sessile +  and petiolate +
alternate +, not +  and rosulate +
cauline +  and basal +
connate +  and distinct +
decurrent +
pinnatifid +
prominent +  and obscure +
tenuinucellate +, crassinucellate +  and bitegmic +
campylotropous +  and anatropous +
0.6 cm6 mm <br />0.006 m <br /> (1 cm10 mm <br />0.01 m <br />) +
rudimentary +
0.2 cm2 mm <br />0.002 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
Flowering Apr-mid May. +
trinucleate +  and 3(-11)-colpate +
ellipsoid +
unbranched;5-14-flowered +
elongated +
reflexed +, ascending +  and erect +
slender +
mucilaginous +
margined +, not winged +  and winged +
biseriate +, sub-biseriate +  and uniseriate +
not +  and mucilaginous +
White (?) +, Black (?) +, Brown (?) +  and Yellow (?) +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
orbicular +, oblong +  and flattened +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
persistent +  and caducous +
distinct +
spreading +, ascending +  and erect +
oblong +  and ovate +
reduced +
latiseptate +, schizocarpic +, samaroid +  and lomentaceous +
indehiscent +  and dehiscent +
angustiseptate +, flat +, angled +, terete +, torulose +, not +, segmented +  and nutletlike +
tetradynamous +
branched +  and unbranched +
procumbent +  and decumbent +
subsessile +, sessile +  and petiolate +
persistent +
distinct +
0.01 cm0.1 mm <br />1.0e-4 m <br /> (0.05 cm0.5 mm <br />5.0e-4 m <br />) +
Cruciferae +
Boechera cusickii +
Boechera +
species +
simple +  and long-stalked +
glabrous +  and pubescent +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.17 cm1.7 mm <br />0.0017 m <br />) +
coiled +, 1-7-veined +  and veined +
anastomosing +
1.5 cm15 mm <br />0.015 m <br /> (2 cm20 mm <br />0.02 m <br />) +
perennial +  and long-lived +
pubescent +  and glabrous +
0.4 cm4 mm <br />0.004 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
rhizomatous +, taprooted +, scapose +  and not +
perennial +, biennial +  and annual +
subshrub +  and herb +
aquatics +  and terrestrial +
glabrous +  and pubescent +
0.1mm;0.2mm +