484 BRASSICACEAE 
2. Arabis petiolaris A. Gray. Annual or biennial, glabrous, or sparingly pubescent 
with reflexed simple hairs. Stems erect, 4-9 dm. tall, simple or branched above: basal 
leaves few, 12-20 em. long, with somewhat lyrate-pinnatifid blades ; segments 5-7, sinuate : 
stem-leaves various; blades all petioled, lower ones pinnatifid or hastately lobed, upper 
entire or merely sinuate: pedicels becoming 6-10 mm. long: petals purplish : pods as- 
cending, 5-7.5 cm. long, 3-4 mm. broad, slender-beaked, the valves 1-nerved below the 
middle : seeds broadly winged. : 
On plains or prairies, Texas, mainly between the Colorado River and the Rio Grande. Spring. 
3. Arabis lyrata L. Biennial or perennial, glabrous, or pubescent near the base. 
Stems solitary or tufted, erect or ascending, 1-4 dm. tall, often diffusely branched : basal 
leaves 1-4 cm. long, with short margined petioles ; blades spatulate or oblanceolate in 
outline, lyrate-pinnatifid : stem-leaves 1-3 cm. long, linear and entire or some of the 
lower ones broader and irregularly toothed : pedicels ascending, 5-10 mm. long: sepals 
oblong, 2-2.5 mm. long, obtuse: petals white, twice or thrice as long as the sepals: pods 
narrowly linear, 2-3 cm. long, ascending, straight or slightly curved : seeds in 1 row, wingless. 
On cliffs and in sandy soil, Ontario to Manitoba, North Carolina and Missouri. Spring. 
4. Arabis dentàta T. & G. Biennial, pubescent with fine rigid stellate hairs. 
Stems erect, 2-6 dm. tall, branching from the base, the branches ascending or decumbent : 
basal leaves spatulate, 5-12 em. long ; petioles winged, shorter than the remotely dentate 
blades: stem-leaves quite numerous ; blades sessile, clasping, more finely toothed than the 
basal, usually oblanceolate to oblong: pedicels 1-3 mm. long, finally spreading: sepals 
oblong, 1.5 mm. long, obtuse: petals white, nearly twice as long as the sepals: pods 
linear, 2-2.5 cm. long, straight, spreading: seeds in 1 row, marginless. 
In moist soil, New York to Minnesota, Virginia (?), Tennessee and Missouri. Spring. 
5. Arabis pàtens Sulliv. Biennial, more or less densely hirsute with simple or 
branched hairs, or rarely glabrous above. Stems solitary or loosely tufted, 3-7 dm. tall, 
simple or sometimes sparingly branched : basal leaves 3-10 cm. long ; blades oblanceolate, 
spatulate or obovate, on winged petioles : stem-leaves shorter than the basal; blades oblan- 
ceolate or obovate to ovate or lanceolate, sessile, serrate or dentate like the basal, but the 
teeth usually more prominent : pedicels finally spreading, 1-2.5 em. long: sepals oblong, 
4-5 mm. long, obtuse, scarious-margined : petals white, twice as long as the sepals: pods 
Sis linear, spreading or erect-spreading, 2.5-4 em. long : seeds in 1 row, narrowly 
winged. 
On river banks, Pennsylvania to Minnesota, Alabama and Missouri. Spring and summer. 
6. Arabis hirsuta (L.) Scop. Biennial, finely hirsute throughout with simple or 
forking hairs. Stems erect, 2-9 dm. tall, simple or nearly so, sometimes branched at the 
base: basal leaves 2-4 cm. long, with short winged petioles, and obovate, elliptic or spat- 
ulate repand or shailowly dentate blades: stem-leaves 1-6 cm. long ; blades sessile, clasp- 
ing by the auricled bases, oblong to lanceolate, or rarely linear, nearly entire, or dentate : 
pedicels erect or nearly so, finally 4-12 mm. long : sepals oblong, 2.5-3 mm. long, obtuse : 
petals greenish white, or nearly white, about twice as long as the sepals: pods narrowly 
linear, 2.5-3 em. long, erect or appressed : seeds in one row, narrowly margined. 
In rocky or poor soil, Newfoundland to British Columbia, Georgia and California. Also in Europe 
and Asia. Spring to fall. 
7. Arabis laevigata (Muhl.) Poir. Biennial, glaucous. Stems erect, 3-10 dm. tall, 
simple, or virgately branched above: basalleaves with varying petioles and spatulate or 
obovate dentate blades: stem-leaves 3-15 cm. long; blades oblong, lanceolate or linear, 
entire or coarsely toothed, sessile, clasping by the strongly auricled bases: pedicels ascend- 
ing, finally spreading, 8-10 mm. long: sepals narrowly oblong, about 5 mm. long, obtuse : 
petals white or greenish white, about twice as long as the sepals: pods narrowly linear, 
6-10 cm. long, partially drooping : seeds in 1 row, broadly winged. 
In rocky soil, Quebee to Minnesota, Georgia and Arkansas. Spring. 
8. Arabis Canadénsis L. Annual or biennial, more or less pubescent. Stems erect, 
2-9 dm. tail, simple, or virgately branched above : basal or lower leaves with short petioles 
and toothed or lyrate-pinnatifid blades: upper stem-leaves 3-12 cm. long ; blades thin, 
lanceolate or oblanceolate, nearly entire or shallowly toothed, acute: pedicels epreenuns 
or recurved at maturity, 5-12 mm. long: sepals oblong, 4 mni. long, obtuse: petals 
greenish white, about twice as long as the sepals: pods scythe-shaped, narrowly linear, 
5-7 em. long, drooping: seeds in 1 row, winged. 
In rocky woods, Ontario to Minnesota, middle Georgia and Texas. Spring and summer. 
24. SOPHIA Adans. 
Annual or perennial caulescent herbs or shrubby plants, more or less densely mue 
with short branched hairs. Leaves alternate: blades 2-pinnatifid, or finely dissected. 
