19 
9. ARABIS L. (Rock CRESS. ) 
Low or tall herbs, with white or purple flowers, short anthers scarcely 
emarginate at base, petals with flat blade and claw, and elongated pods 
flattened parallel to the broad partition. 
1. A. Ludoviciana Meyer. Low, diffuse or spreading from the base, nearly gla- 
brous: leaves all pinnately parted into oblong or linear few-toothed or entire divi- 
sions, those of the lower Jeaves numerous: flowers small, white: pods rather broadly 
linear, spreading, flat; seeds winged.—One of the earliest bloomers in the valleys of 
southern and western Texas. 
2. A. petiolaris Gray. Mostly simple, 6 to 9 dm. high, wholly glabrous except 
the base of the stem and the lowest leaves: leaves ample, 7.5 to 17.5 em. long, on pe- 
tioles about half as long; the lower with a hastate-lanceolate or triangular outline; 
the upper broadly lanceolate, with a truncate, rounded, or even tapering base, all 
more or less lyrately cut or lobed (or the uppermost entire): flowers white, tinged 
with purple: pods numerous, broadly linear, 7.5 cm. long; seeds very broadly 
winged.—In thickets and shady woods from the Colorado to the Rio Grande and to 
the mountains of western Texas, 
10. STREPTANTHUS Nutt. 
Mostly glabrous and glaucous annuals or biennials, with cordate or 
sagittate-clasping toothed or entire leaves, broad and usuall y colored 
sepals, twisted or undulate petals (rose-purple in ours), elongated 
Sagittate anthers, and elongated pods flattened parallel to the broad 
partition. 
* Petals with a broad and ample plane blade. 
1. S. bracteatus Gray. Lower leaves from entire to lyrate-pinnatifid ; all deeply 
cordate-clasping, merging gradually into the persistent bracts which subtend all the 
flowers: pods elongated-linear, 15 em. long or more, spreading —Sand bars of the 
Colorado and Guadalupe, and undoubtedly along other rivers of southern and western 
Texas, 
2. S. platycarpus Gray. Leaves clasping by rather short and rounded lobes, the 
lower and radical ones lyrate-piunatifid : flowers (or all but the lowest) bractless: 
pods oblong-linear, 5 to 6 mm. broad and 5 to 7.5 em. long, very flat, erect.—On 
stony hills, valleys of the Pecos and San Antonio, and doubtless other rivers of south- 
western Texas. 
** Petals undulate-crisped, the blade narrow or attenuate, scarcely if at all broader than 
_ the claw, 
3. S. carinatus Wright. Radical and lower stem leaves runcinate, the upper ones 
sagittate-clasping, all very glaucous: calyx urceolate and carinately 5-saccate: fila- 
ments distinct: pedicels of the flowers and of the broadly linear and flat (half-grown) 
pods erect.—Cafions and rocky hills near the Rio Grande in extreme western Texas, 
extending into New Mexico and northern Mexico. 
4. S. hyacinthoides Hook. Cauline leaves oblong-linear, acuminate, scarcely 
sagittate-clasping or not at all: one pair of the longer filaments connate : pods nar- 
row.—Indian Territory, and extending into northeastern Texas, probably within our 
range at the north. 
ll. GREGGIA Gray. 
Low stellately pubescent plants, with rather large white or purple 
flowers, sugittate coiled anthers (at maturity), and linear elongated 
