Boechera duchesnensis

(Rollins) Windham

Harvard Pap. Bot. 12: 239. 2007.

Basionym: Arabis pulchra var. duchesnensis Rollins Syst. Bot. 6: 59. 1981
Synonyms: Boechera pulchra var. duchesnensis (Rollins) Dorn
Treatment appears in FNA Volume 7. Treatment on page 375. Mentioned on page 354.

Perennials; usually long-lived; apomictic; caudex often woody. Stems usually 1 per caudex branch, arising from center of rosette, elevated on woody base or from near ground surface, 1.5–4.5 dm, densely pubescent proximally, trichomes short-stalked, 2–7-rayed, 0.2–0.5 mm (sometimes mixed with some larger trichomes proximally), sparsely pubescent distally. Basal leaves: blade linear-oblanceolate, 2–5 mm wide, margins entire or denticulate, ciliate at petiole base, trichomes (simple), to 1 mm, surfaces densely pubescent, trichomes short-stalked, 4–8-rayed, 0.15–0.4 mm. Cauline leaves: 3–8, not concealing stem; blade auricles 0.7–2 mm, surfaces of distalmost leaves sparsely pubescent. Racemes 11–22-flowered, usually unbranched. Fruiting pedicels horizontal, straight or slightly curved, 7–14 mm, pubescent, trichomes appressed, branched. Flowers divaricate-ascending at anthesis; sepals pubescent; petals whitish to pale lavender, 7–10 × 1.5–3 mm, glabrous; pollen spheroid. Fruits horizontal, not appressed to rachis, not secund, usually straight, edges parallel, 3.5–5 cm × 1.7–2 mm; valves glabrous proximally, pubescent distally; ovules 72–92 per ovary; style 0.1–0.3 mm. Seeds sub-biseriate, 1.1–1.3 × 0.7–1 mm; wing continuous, ca. 0.1 mm wide.


Phenology: Flowering May.
Habitat: Sandy soil on rocky slopes, mostly in pinyon-juniper woodlands
Elevation: 1300-1800 m

Discussion

Morphological and isozyme analyses indicate that Boechera duchesnensis is an apomictic species that arose through hybridization between B. formosa and B. pallidifolia (M. D. Windham and Allphin, unpubl.). It is easily distinguished from those species by having fruits that are glabrous proximally and sparsely pubescent distally. It shares this distinctive fruit pubescence with B. xylopoda, an apomictic hybrid between B. perennans and B. pulchra (see 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.

... more about "Boechera duchesnensis"
oblong +  and ovate +
Ihsan A. Al-Shehbaz +  and Michael D. Windham +
(Rollins) Windham +
not +  and rosulate +
Arabis pulchra var. duchesnensis +
appendaged +  and unappendaged +
0.07 cm0.7 mm <br />7.0e-4 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
lyrate-pinnatifid +, dentate +  and entire +
dissected +, repand +, sinuate +, crenate +  and dentate +
linear-oblanceolate +
much smaller +  and reduced +
2mm;5mm +
urceolate +, campanulate +  and tubular +
branched +  and simple +
petiolate +  and sessile +
well-developed +
indistinct +
not +  and differentiated +
emarginate +  and entire +
Colo. +, N.Mex. +  and Utah. +
3.5 cm35 mm <br />0.035 m <br /> (5 cm50 mm <br />0.05 m <br />) +
0.17 cm1.7 mm <br />0.0017 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
1300-1800 m +
straight +  and curved +
not winged +  and unappendaged +
connate +  and distinct +
actinomorphic +
divaricate-ascending +
straight +
torulose +, falcate +, lanceolate +, oblong +  and linear +
Sandy soil on rocky slopes, mostly in pinyon-juniper woodlands +
annular +  and semiannular +
sessile +  and petiolate +
alternate +, not +  and rosulate +
cauline +  and basal +
connate +  and distinct +
decurrent +
dentate +  and entire +
denticulate;entire +
prominent +  and obscure +
tenuinucellate +, crassinucellate +  and bitegmic +
campylotropous +  and anatropous +
0.7 cm7 mm <br />0.007 m <br /> (1 cm10 mm <br />0.01 m <br />) +
rudimentary +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
Flowering May. +
trinucleate +  and 3(-11)-colpate +
spheroid +
Harvard Pap. Bot. +
unbranched;11-22-flowered +
elongated +
reflexed +, ascending +  and erect +
slender +
mucilaginous +
margined +, not winged +  and winged +
sub-biseriate +
not +  and mucilaginous +
White (?) +, Black (?) +, Brown (?) +  and Yellow (?) +
0.11 cm1.1 mm <br />0.0011 m <br /> (0.13 cm1.3 mm <br />0.0013 m <br />) +
orbicular +, oblong +  and flattened +
0.07 cm0.7 mm <br />7.0e-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 +
0.01 cm0.1 mm <br />1.0e-4 m <br /> (0.03 cm0.3 mm <br />3.0e-4 m <br />) +
Boechera pulchra var. duchesnensis +
Boechera duchesnensis +
Boechera +
species +
branched +  and short-stalked +
0.015 cm0.15 mm <br />1.5e-4 m <br /> (0.04 cm0.4 mm <br />4.0e-4 m <br />) +
coiled +, 1-7-veined +  and veined +
pubescent +  and glabrous +
anastomosing +
curved +  and straight +
perennial +  and long-lived +
0.7 cm7 mm <br />0.007 m <br /> (1.4 cm14 mm <br />0.014 m <br />) +
rhizomatous +, taprooted +, scapose +  and not +
perennial +, biennial +  and annual +
subshrub +  and herb +
aquatics +  and terrestrial +
glabrous +  and pubescent +