Boechera evadens

Windham & Al-Shehbaz

Harvard Pap. Bot. 11: 66. 2006.

Treatment appears in FNA Volume 7. Treatment on page 376. Mentioned on page 364.
Revision as of 12:16, 30 July 2020 by imported>Volume Importer
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Perennials; long-lived; (cespitose); sexual; caudex woody. Stems usually 1 per caudex branch, arising from center of rosette near ground surface, 1–2.5 dm, densely pubescent proximally, trichomes short-stalked, 2–5-rayed, 0.2–0.6 mm, and sparse, simple ones to 1 mm, glabrous distally. Basal leaves: blade narrowly oblanceolate, 1.5–3 mm wide, margins entire, ciliate along petiole, trichomes (simple), to 1 mm, surfaces densely pubescent, trichomes short-stalked, 4–8-rayed, 0.1–0.2 mm. Cauline leaves: 3–5, not concealing stem; blade auricles 0.5–1 mm, surfaces of distalmost leaves pubescent. Racemes 10–22-flowered, unbranched. Fruiting pedicels divaricate-ascending, straight, 4–8 mm, sparsely pubescent, trichomes appressed, branched. Flowers ascending at anthesis; sepals pubescent; petals white, 3–4 × 0.5–0.8 mm, glabrous; pollen ellipsoid. Fruits divaricate-ascending, not appressed to rachis, not secund, straight, edges parallel, 3–4 cm × 1.2–1.5 mm; valves glabrous; ovules 46–52 per ovary; style ca. 0.1 mm. Seeds uniseriate, 1–1.1 × 0.9–1 mm; wing continuous, ca. 0.1 mm wide.


Phenology: Flowering Jun.
Habitat: Rock outcrops
Elevation: ca. 2600 m

Discussion

Boechera evadens is a sexual taxon that was originally interpreted as a disjunct population of Arabis (Boechera) fernaldiana, but is easily distinguished from that species by having much shorter (3–4 versus 7–12 mm) petals, larger (0.2–0.6 versus 0.04–0.1 mm) trichomes proximally on stems, and shorter (3–4 versus 4–7.5 cm) fruits (see M. D. Windham and I. A. Al-Shehbaz 2006 for additional distinctions). It is known only from the holotype specimen collected near Sherman Pass in Tulare County.

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 evadens"
oblong +  and ovate +
Ihsan A. Al-Shehbaz +  and Michael D. Windham +
Windham & Al-Shehbaz +
not +  and rosulate +
appendaged +  and unappendaged +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
not +  and auriculate +
lyrate-pinnatifid +, dentate +  and entire +
dissected +, repand +, sinuate +, crenate +  and dentate +
oblanceolate +
much smaller +  and reduced +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
urceolate +, campanulate +  and tubular +
branched +  and simple +
petiolate +  and sessile +
well-developed +
indistinct +
not +  and differentiated +
emarginate +  and entire +
3 cm30 mm <br />0.03 m <br /> (4 cm40 mm <br />0.04 m <br />) +
0.12 cm1.2 mm <br />0.0012 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
ca. 2600 m +
straight +  and curved +
not winged +  and unappendaged +
connate +  and distinct +
actinomorphic +
straight +
divaricate-ascending +
torulose +, falcate +, lanceolate +, oblong +  and linear +
Rock outcrops +
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 +
rudimentary +
oblanceolate +  and spatulate +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.08 cm0.8 mm <br />8.0e-4 m <br />) +
Flowering Jun. +
trinucleate +  and 3(-11)-colpate +
ellipsoid +
Harvard Pap. Bot. +
unbranched;10-22-flowered +
reflexed +, ascending +  and erect +
slender +
mucilaginous +
margined +, not winged +  and winged +
biseriate +, sub-biseriate +  and uniseriate +
not +  and mucilaginous +
white +, black +, brown +  and yellow +
0.1 cm1 mm <br />0.001 m <br /> (0.11 cm1.1 mm <br />0.0011 m <br />) +
orbicular +, oblong +  and flattened +
0.09 cm0.9 mm <br />9.0e-4 m <br /> (0.1 cm1 mm <br />0.001 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 +
0.1 cm1 mm <br />0.001 m <br /> (?) +
Cruciferae +
Boechera evadens +
Boechera +
species +
branched +, short-stalked +  and simple +
0.01 cm0.1 mm <br />1.0e-4 m <br /> (0.02 cm0.2 mm <br />2.0e-4 m <br />) +
coiled +, 1-7-veined +  and veined +
anastomosing +
perennial +  and long-lived +
divaricate-ascending +
0.4 cm4 mm <br />0.004 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
rhizomatous +, taprooted +, scapose +  and not +
perennial +, biennial +  and annual +
subshrub +  and herb +
aquatics +  and terrestrial +
glabrous +  and pubescent +