Boechera saximontana

(Rollins) Windham & Al-Shehbaz

Harvard Pap. Bot. 12: 248. 2007.

Basionym: Arabis microphylla var. saximontana Rollins Rhodora 43: 429. 1941
Synonyms: Arabis pendulocarpa var. saximontana (Rollins) Dorn Arabis williamsii var. saximontana (Rollins) Rollins Boechera williamsii var. saximontana (Rollins) Dorn
Treatment appears in FNA Volume 7. Treatment on page 404. Mentioned on page 362.

Perennials; short-lived; apomictic; caudex usually not woody. Stems usually 1 per caudex branch, arising from center of rosette near ground surface, 0.7–3 dm, densely pubescent proximally, trichomes short-stalked, 2–6-rayed, 0.06–0.25 mm, glabrous distally. Basal leaves: blade narrowly oblanceolate, 1–3 mm wide, margins entire, ciliate near petiole base, trichomes (simple and spurred), to 0.4 mm, surfaces sparsely to densely pubescent, trichomes short-stalked, 4–8-rayed, 0.04–0.15 mm. Cauline leaves: 5–9, rarely concealing stem proximally; blade auricles to 0.3–1 mm, surfaces of distalmost leaves glabrous. Racemes 5–13-flowered, usually unbranched. Fruiting pedicels divaricate-ascending, straight, 3–8 mm, glabrous. Flowers ascending at anthesis; sepals pubescent; petals lavender, 4–5 × 0.5–0.8 mm, glabrous; pollen spheroid. Fruits divaricate-ascending, not appressed to rachis, not secund, straight, edges parallel, (2.5–) 3–4.7 cm × 1.2–1.7 mm; valves glabrous; ovules 78–112 per ovary; style 0.1–0.5 mm. Seeds uniseriate to sub-biseriate, 1.1–1.4 × 0.7–0.9 mm; wing continuous, 0.05–0.12 mm wide.


Phenology: Flowering Jun–Jul.
Habitat: Rocky soil in sagebrush and open conifer forests
Elevation: 2400-2900 m

Discussion

Boechera saximontana is an apomictic taxon that has been treated as a variety of either Arabis microphylla (R. C. Rollins 1941) or A. (Boechera) williamsii (Rollins 1993; R. D. Dorn 2001). It is easily distinguished from typical collections of those species (see M. D. Windham and I. A. Al-Shehbaz 2007b for detailed comparison), but it is likely that one (or both) were involved in its hybrid origin. It is known from Blaine, Custer, and Lemhi counties in Idaho, and Big Horn and Fremont counties in Wyoming.

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 saximontana"
oblong +  and ovate +
Ihsan A. Al-Shehbaz +  and Michael D. Windham +
(Rollins) Windham & Al-Shehbaz +
not +  and rosulate +
Arabis microphylla var. saximontana +
appendaged +  and unappendaged +
0.03 cm0.3 mm <br />3.0e-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 +
0.1 cm1 mm <br />0.001 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 +
Idaho +  and Wyo. +
2.5 cm25 mm <br />0.025 m <br /> (3 cm30 mm <br />0.03 m <br />) +
3 cm30 mm <br />0.03 m <br /> (4.7 cm47 mm <br />0.047 m <br />) +
0.12 cm1.2 mm <br />0.0012 m <br /> (0.17 cm1.7 mm <br />0.0017 m <br />) +
2400-2900 m +
straight +  and curved +
not winged +  and unappendaged +
connate +  and distinct +
actinomorphic +
straight +
divaricate-ascending +
torulose +, falcate +, lanceolate +, oblong +  and linear +
Rocky soil in sagebrush and open conifer forests +
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 +
magenta +, red +, yellowish +, purple +, lavender +, pink +  and white +
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–Jul. +
trinucleate +  and 3(-11)-colpate +
spheroid +
Harvard Pap. Bot. +
unbranched;5-13-flowered +
divaricate-ascending +
slender +
0.3 cm3 mm <br />0.003 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
mucilaginous +
margined +, not winged +  and winged +
uniseriate +  and sub-biseriate +
not +  and mucilaginous +
white +, black +, brown +  and yellow +
0.11 cm1.1 mm <br />0.0011 m <br /> (0.14 cm1.4 mm <br />0.0014 m <br />) +
orbicular +, oblong +  and flattened +
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 +
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 />) +
glabrous +  and pubescent +
Arabis pendulocarpa var. saximontana +, Arabis williamsii var. saximontana +  and Boechera williamsii var. saximontana +
Boechera saximontana +
Boechera +
species +
0.004 cm0.04 mm <br />4.0e-5 m <br /> (0.015 cm0.15 mm <br />1.5e-4 m <br />) +
coiled +, 1-7-veined +  and veined +
anastomosing +
perennial +  and short-lived +
hispid +, hirsute +, pubescent +  and glabrous +
rhizomatous +, taprooted +, scapose +  and not +
perennial +, biennial +  and annual +
subshrub +  and herb +
aquatics +  and terrestrial +
glabrous +  and pubescent +
0.05mm;0.12mm +