Boechera johnstonii

(Munz) Al-Shehbaz

Novon 13: 386. 2003.

Basionym: Arabis johnstonii Munz Bull. S. Calif. Acad. Sci. 31: 63. 1932
Synonyms: Arabis hirshbergiae S. Boyd Boechera hirshbergiae (S. Boyd) Al-Shehbaz
Treatment appears in FNA Volume 7. Treatment on page 386. Mentioned on page 353.

Perennials; long-lived; (cespitose); sexual; caudex woody. Stems usually 1 per caudex branch, arising from center of rosette near ground surface, 0.5–2 dm, densely pubescent proximally, trichomes short-stalked, 4–10-rayed, 0.07–0.15 mm, sparsely to densely pubescent distally. Basal leaves: blade narrowly oblanceolate, 1.5–4 mm wide, margins entire, not ciliate, surfaces densely pubescent, trichomes short-stalked, 6–14-rayed, 0.07–0.15 mm. Cauline leaves: 4–10, often concealing stem proximally; blade auricles absent, surfaces of distalmost leaves densely pubescent. Racemes 10–18-flowered, unbranched. Fruiting pedicels divaricate-ascending, straight, 5–14 mm, pubescent, trichomes appressed, branched. Flowers ascending at anthesis; sepals pubescent; petals purple, 9–14 × 2–4 mm, glabrous; pollen ellipsoid. Fruits divaricate-ascending, not appressed to rachis, not secund, straight, edges parallel, 4–6 cm × 2.5–4 mm; valves glabrous; ovules 26–34 per ovary; style (0.7–) 1–2 mm. Seeds uniseriate, 1.9–2.7 × 1.5–2.2 mm; wing continuous, 0.3–0.7 mm wide.


Phenology: Flowering Feb–Mar.
Habitat: Rocky areas and gravelly soil in chaparral and oak-pine savannas
Elevation: 1300-1700 m

Discussion

Of conservation concern.

Boechera johnstonii and B. hirshbergiae are too similar to be considered distinct species. Even with the expanded circumscription, this distinctive sexual species is known only from the area of Cuyamaca Lake (San Diego County) and the San Jacinto Mountains (Riverside 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 johnstonii"
oblong +  and ovate +
Ihsan A. Al-Shehbaz +  and Michael D. Windham +
(Munz) Al-Shehbaz +
not +  and rosulate +
Arabis johnstonii +
appendaged +  and unappendaged +
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 /> (0.4 cm4 mm <br />0.004 m <br />) +
urceolate +, campanulate +  and tubular +
branched +  and simple +
petiolate +  and sessile +
well-developed +
indistinct +
not +  and differentiated +
emarginate +  and entire +
4 cm40 mm <br />0.04 m <br /> (6 cm60 mm <br />0.06 m <br />) +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
1300-1700 m +
straight +  and curved +
not winged +  and unappendaged +
connate +  and distinct +
actinomorphic +
straight +
divaricate-ascending +
torulose +, falcate +, lanceolate +, oblong +  and linear +
Rocky areas and gravelly soil in chaparral and oak-pine savannas +
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 +
9mm;14mm +
rudimentary +
oblanceolate +  and spatulate +
0.2 cm2 mm <br />0.002 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
Flowering Feb–Mar. +
trinucleate +  and 3(-11)-colpate +
ellipsoid +
unbranched;10-18-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 +
0.19 cm1.9 mm <br />0.0019 m <br /> (0.27 cm2.7 mm <br />0.0027 m <br />) +
orbicular +, oblong +  and flattened +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.22 cm2.2 mm <br />0.0022 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 +
0.07 cm0.7 mm <br />7.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
persistent +
distinct +
0.1 cm1 mm <br />0.001 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
Arabis hirshbergiae +  and Boechera hirshbergiae +
Boechera johnstonii +
Boechera +
species +
branched +  and short-stalked +
0.007 cm0.07 mm <br />7.0e-5 m <br /> (0.015 cm0.15 mm <br />1.5e-4 m <br />) +
coiled +, 1-7-veined +  and veined +
anastomosing +
perennial +  and long-lived +
divaricate-ascending +
0.5 cm5 mm <br />0.005 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 +
0.3mm;0.7mm +