170 CRUCIFERAE. 



flowers white or purple; pod long-linear, compressed parallel 

 to the partition; valves more or less 1-nerved; seeds flattened, 

 usually winged, in one or two rows. 



Seeds wingless; flowers white. 



Basal leaves pinnately cleft into short and broad seg- 

 ments. A. lyrata. 

 Basal leaves entire; cauline auriculate. A. glabra. 

 Seeds winged or wing-margined. 

 Seeds arranged in a single row. 



Cauline leaves cordate or auriculate at base. A. hirsuta. 



Cauline leaves not cordate nor auricled. 



Pubescence of very fine stellate hairs or none; pods 



broad. A. platysperma. 



Pubescence of simple or forked hairs; pods narrow. 



Petals small, not exceeding the sepals. A. olympica. 



Petals much longer than the sepals. A . furcata. 



Seeds more or less distinctly in two rows. 



Pods reflexed. A. patula. 



Pods erect or ascending. 



Tall, 30-60 cm. high; plant somewhat glaucous; 



pubescence of 2-forked hairs. A. drummondii. 



Low, 10-30 cm. high; plant glabrous or somewhat 



stellate-pubescent below. A . lyallii. 



Arabis lyrata occidentalis Wats. Pubescent at base, glabrous above 

 stems branching from the base, ascending, 20-30 cm. high; basal leaves lyrate- 

 pinnatifid or sometimes nearly entire; cauline leaves spatulate to linear, 

 mostly entire; petals white; pods ascending or spreading, very slender, flat- 

 tened; stigma sessile or on a very short style; seeds oblong, wingless. 



Nooksack River, Whatcom County, Washington, Suksdorf. 



Arabis glabra (L.) Bernh. Biennial, pubescent near the base, glabrous and 

 glaucous above; stems usually simple, 60-90 cm. high; basal leaves oblanceolate, 

 dentate or pinnatifid, pubescent, 5-8 cm. long; cauline oblong-lanceolate, 

 sessile, sagittate and auricled at base, all but the lower glabrous; flowers whitish, 

 about 5 mm. long; pods erect or ascending, linear, 4-10 cm. long, tipped with 

 the large 2-lobed sessile stigma; pedicels 4-10 mm. long. 



Fields and open places, not rare. 



Arabis hirsuta (L.) Scop. Biennial, usually rough-hairy, but shade plants 

 often nearly glabrous; stems erect, 15-50 cm. high; basal leaves clustered, 

 oblanceolate, entire or somewhat dentate, usually 2-5 cm. long; cauline oblong 

 to lanceolate, entire or dentate, cordate or auriculate at base; flowers greenish 

 white, small ; pods on slender pedicels, erect, slender, 2-5 cm. long, tipped with 

 a very short stout style. 



On rocky cliffs or gravelly bars, infrequent. 



Arabis platysperma Gray. Perennial from a branched rootstock, finely 

 stellate-pubescent to nearly glabrous, glaucous; leaves all entire, the basal 

 oblanceolate and petiolate, 10-30 cm. high, the cauline oblong to lanceolate and 

 sessile; flowers rose-colored or white; pods erect or ascending, flattened, the 

 valves veiny, 3-6 cm. long, 3-5 mm. broad, tipped with a short style; seeds 

 circular, broadly winged. 



Mount Hood, Oregon, and southward in the mountains. 



Arabis olympica Piper. Perennial, sparsely pubescent with simple or 

 branched hairs; basal leaves obovateto oblanceolate, obscurely crenate, obtuse, 

 petiolate, about 8 mm. long; cauline sessile, oblong to lanceolate, obtuse, 



