Boechera gracilenta

(Greene) Windham & Al-Shehbaz

Harvard Pap. Bot. 12: 240. 2007.

Basionym: Arabis gracilenta Greene Pittonia 4: 194. 1900
Synonyms: Arabis selbyi Rydberg Boechera selbyi (Rydberg) W. A. Weber
Treatment appears in FNA Volume 7. Treatment on page 381. Mentioned on page 358, 363, 396.

Perennials; short or (rarely) long-lived; apomictic; caudex usually not woody. Stems 1–9 per caudex branch, arising from center or margin of rosette near ground surface, (1.5–) 2.5–5.5 dm, densely pubescent proximally, trichomes short-stalked, 2–4-rayed, 0.1–0.5 mm, mixed with some simple ones, to 0.8 mm, glabrous distally. Basal leaves: blade oblanceolate, 2–9 mm wide, margins shallowly dentate or sometimes entire, ciliate proximally, trichomes (simple and spurred), to 1.2 mm, surfaces moderately to densely pubescent, trichomes short-stalked, 4–6 (–8) -rayed, 0.1–0.5 mm. Cauline leaves: 4–9, not concealing stem; blade auricles 1–3 mm, surfaces of distalmost leaves usually glabrous. Racemes 7–20-flowered, usually unbranched. Fruiting pedicels divaricate-ascending, gently curved downward, (7–) 10–18 mm, glabrous. Flowers ascending at anthesis; sepals pubescent; petals lavender, 6–7 × 1.5–2 mm, glabrous; pollen spheroid. Fruits usually widely pendent, rarely horizontal, not appressed to rachis, not secund, slightly curved, edges parallel, (3–) 4.5–7 cm × 1.7–2 mm; valves glabrous; ovules 60–96 per ovary; style 0.1–0.3 mm. Seeds sub-biseriate, 1.2–1.8 × 0.9–1.2 mm; wing continuous, 0.1–0.25 mm wide.


Phenology: Flowering Apr–May.
Habitat: Rocky slopes and sandy soil in pinyon-juniper woodlands and mountain shrub communities
Elevation: 1900-2300 m

Distribution

V7 532-distribution-map.gif

Ariz., Colo., N.Mex., Utah.

Discussion

Morphological evidence suggests that Boechera gracilenta is an apomictic species that arose through hybridization between B. fendleri and B. pallidifolia; it is superficially similar to the sexual diploid B. perennans but is not closely related (see M. D. Windham and I. A. Al-Shehbaz 2007b for detailed comparison).

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 "Boechera gracilenta"
oblong +  and ovate +
Ihsan A. Al-Shehbaz +  and Michael D. Windham +
(Greene) Windham & Al-Shehbaz +
not +  and rosulate +
Arabis gracilenta +
appendaged +  and unappendaged +
0.1 cm1 mm <br />0.001 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
not +  and auriculate +
lyrate-pinnatifid +, dentate +  and entire +
dissected +, repand +, sinuate +, crenate +  and dentate +
oblanceolate +
much smaller +  and reduced +
0.2 cm2 mm <br />0.002 m <br /> (0.9 cm9 mm <br />0.009 m <br />) +
urceolate +, campanulate +  and tubular +
branched +  and simple +
petiolate +  and sessile +
well-developed +
indistinct +
not +  and differentiated +
emarginate +  and entire +
Ariz. +, Colo. +, N.Mex. +  and Utah. +
3 cm30 mm <br />0.03 m <br /> (4.5 cm45 mm <br />0.045 m <br />) +
4.5 cm45 mm <br />0.045 m <br /> (7 cm70 mm <br />0.07 m <br />) +
0.17 cm1.7 mm <br />0.0017 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
1900-2300 m +
straight +  and curved +
not winged +  and unappendaged +
connate +  and distinct +
actinomorphic +
horizontal +  and pendent +
torulose +, falcate +, lanceolate +, oblong +  and linear +
Rocky slopes and sandy soil in pinyon-juniper woodlands and mountain shrub communities +
annular +  and semiannular +
sessile +  and petiolate +
alternate +, not +  and rosulate +
cauline +  and basal +
connate +  and distinct +
decurrent +
entire +  and dentate +
pinnatifid +
prominent +  and obscure +
tenuinucellate +, crassinucellate +  and bitegmic +
campylotropous +  and anatropous +
magenta +, red +, yellowish +, purple +, lavender +, pink +  and white +
rudimentary +
oblanceolate +  and spatulate +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
Flowering Apr–May. +
trinucleate +  and 3(-11)-colpate +
spheroid +
Harvard Pap. Bot. +
unbranched;7-20-flowered +
0.7 cm7 mm <br />0.007 m <br /> (1 cm10 mm <br />0.01 m <br />) +
downward +  and divaricate-ascending +
slender +
1 cm10 mm <br />0.01 m <br /> (1.8 cm18 mm <br />0.018 m <br />) +
mucilaginous +
margined +, not winged +  and winged +
sub-biseriate +
not +  and mucilaginous +
white +, black +, brown +  and yellow +
0.12 cm1.2 mm <br />0.0012 m <br /> (0.18 cm1.8 mm <br />0.0018 m <br />) +
orbicular +, oblong +  and flattened +
0.09 cm0.9 mm <br />9.0e-4 m <br /> (0.12 cm1.2 mm <br />0.0012 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 +
1 +  and 9 +
subsessile +, sessile +  and petiolate +
persistent +
distinct +
0.01 cm0.1 mm <br />1.0e-4 m <br /> (0.03 cm0.3 mm <br />3.0e-4 m <br />) +
glabrous +  and pubescent +
Arabis selbyi +  and Boechera selbyi +
Boechera gracilenta +
Boechera +
species +
0.01 cm0.1 mm <br />1.0e-4 m <br /> (0.05 cm0.5 mm <br />5.0e-4 m <br />) +
coiled +, 1-7-veined +  and veined +
anastomosing +
perennial +  and long-lived +
hispid +, hirsute +, pubescent +  and glabrous +
rhizomatous +, taprooted +, scapose +  and not +
perennial +, biennial +  and annual +
subshrub +  and herb +
aquatics +  and terrestrial +
glabrous +  and pubescent +
0.1mm;0.25mm +