46 CRUCIFER A. ARABIS. 
STREPTANTHUS. 
A. Columbiana Macoun Cat. Canada PI. ii, 304. Winter annual: al- 
most smooth or pubescent below with branching hairs: lower leaves 
slightly toothed and tapering into a petiole ; cauline sessile and often clasp- 
ing: flowers white: pods exactly sickle-shaped, 3-4 inches long. Common 
on the lower slopes of mountains, northern Washington to Brit. Columbia. 
A. eanescens T. & G. FI. i, 83. Finely stellate-pubescent throughout: 
stems one to several from a perennial or biennial root, 2-8 inches high; 
simple or branched: lower leaves linear-oblanceolate, an inch long or less; 
cauline leaves linear, clasping but hardly auriculate: flowers small 2 lines 
or less long, pale: pods pendulous, pubescent or glabrate, 1-14 inches 
long by less than a line broad, on pedicels 1-3 lines long; valves J-nerved 
to the middle: seeds small, orbicular, winged, in 1 or 2 rows. On dry 
plains, Blue Mountains and Harney valley Oregon, to the Rocky 
Mountains and Brit. Columbia. 
A. areuata Gray Proc. Am. Acad. vi, 187 (?). More or less stellate- 
pubescent or hirsute: stems erect, 6 inches to 2 feet or more high from a 
perennial woody caudex, simple or branched ; lower leaves spatulate, entire 
or denticulate acute, 1-2 inches long; cauline oblong-lanceolate, sagit- 
tate and clasping at base 6-12 lines long or more; racemes rather few-flow- 
ered; flowers pale nodding; petals 3-4 lines long, white or purple, twice as 
long as the sepals: pods 1-4 inches long by a line or more broad erect 
and slightly curved or spreading and strongly faleate. On rocky ridges 
and dry plains, eastern Oregon and Washington to southwestern Oregon. 
A. subpinnatifida Watson Proc. Am. Acad. xx, 353. Canescent with a 
very fine and dense stellate pubescence: stems 1 to several from a branch- 
ing somewhat woody base: lower leaves crowded and persistent, linear- 
oblanceolate, entire or sparingly toothed, 9-12 lines long; upper ones 
lanceolate, coarsely and subpinnatifidly toothed: flowers pale pink, 3-3 
lines long: pods strongly reflexed, on pedicels 2-5 lines long, 144-3 inches 
long, 1-14% lines broad, more or less attenuate to the short style, pubes- 
cent, slightly curved; valves 1-nerved to the middle and vVeined; seeds in 
one row, as broad as the partition, winged. On dry rocky ridges, south- 
western Oregon and and adjacent California to northwestern Nevada. 
7 STREPTANTHUS Nutt. Jour. Acad. Philad. v, 134, t. 7. 
Caulescent branching herbs with entire or toothed, or rarely 
pinnatifid leaves and purple white or yellowish flowers. Sepals 
ovate or oblong usually colored, equal at base (rarely one or both 
pair saccate), commonly connivent. Petals often without a di- 
lated blade, more or less twisted or undulate; the claw chan- 
neleJ. Stamens 6, the longer pair often connate below. Anthers 
‘more or less elongated, sagittate at base. Pods sessile upon the 
enlarged receptacle, oblong to narrowly linear compressed to sub- 
terete: valves 1-nerved; partition hyaline: stigma simple. Seeds 
flat, margined cr winged. Cvotyledons accumbent. Ours all of 
- § Euxuista T. & G. Fl. 1,67. Petals narrow, the blade but 
little if any broader than the claw, undulate ecrisped. Calyx 
closed or with spreading tips. — | | 
S. orbiculatus Greene Fl. Francis. 258. Glabrous and glacous: stems 
erect from an annual or biennial root, 6-18 inches high, diffusely branched 
from the base: lowest leaves round obovate, very obtuse or even truncate, 
crenately or more remotely and repandly toothed, abruptly narrowed to a 
petiole sa long as the blade: middle cauline obovate-spatulate, auricled 
and clasping; uppermost orbicular, mostly entire, obtuse, sepals purple, 
