the lobes oblong and dentate, gradually changing upward on the plant to leaves 

 with linear-filiform entire segments; flowers loosely racemose; petals pale-yellow, 

 6-9 mm. long; pedicels straight, widely spreading, similar in diameter to siliques; 

 siliques terete, straight, long-linear, widely spreading and extending same angle 

 as pedicel, 5-10 cm. long, glabrous; styles 1-2 mm. long; seeds wingless, plump, 

 oblong, about 1 mm. long; cotyledons incumbent. 



An ubiquitous weed of fields, roadsides and waste places, also wet meadows, 

 edge of ponds and streams, throughout most of our region, May-Aug.; nat. 

 of Eur. 



5. Descurainia Webb & Berth. Tansy-mustard 



More than 50 species in the cold and temperate regions of America, Eurasia 

 and South Africa. 



1. Descurainia calif omica (Gray) Schulz. 



Annual or biennial; stems erect, 3-8 dm. tall, branched above, glabrous or 

 very sparsely pubescent below; leaves simply pinnate; pinnae in 2 to 4 pairs, 

 lanceolate, about 5 cm. long, entire to serrulate or somewhat incised, often 

 slightly pubescent; pedicels slender, 3-7 mm. long, erect-ascending to somewhat 

 spreading; petals yellow, 1.5-2 mm. long, barely exceeding the sepals; fruit 3-6 

 mm. long, to about 1.3 mm. thick, fusiform, the style 0.5 mm. long or more; 

 seeds 2 to 7, in 1 row in each cell. 



In marshes and in wet soil at head of ponds in N.M. (Taos Co.) and Ariz. 

 (Apache and Coconino cos.), June-Sept.; Wyo. to Ore., s. to N.M., Ariz, and 

 Calif. 



6. Cardamine L. Bitter-cress 



Annual, biennial or perennial herbs, glabrous to sparsely hirsute with simple 

 trichomes; leaves entire to pinnately compound, petiolate, alternate; flowers in 

 racemes or panicles; petals white or purple, obovate to spatulate; siliques linear, 

 straight, slightly compressed parallel to septum; valves opening elastically from 

 silique base; replum margin extending partially over valvular area; seeds uni- 

 seriate, marginless, plump, longer than broad; cotyledons accumbent. 



Between 150 to 175 species, cosmopolitan, mostly temperate. 



1. Perennials with slender or tuberous rootstocks; leaves simple, the cordate-ovate 

 to obovate or reniform blades entire to repand or shallowly den- 

 tate (2) 



1. Annuals with fibrous roots; leaves pinnately lobed to compound (3) 



2(1). Stems from a short hard tuber; distribution in eastern Texas 



1. C. bulbosa. 



2. Stems from a slender creeping rootstock; distribution in New Mexico and 



Arizona 2. C cordifolia. 



3(1). Siliques 1.5-2 mm. wide; petals greenish, strap-shaped 



3. C. macrocarpa var. texana. 



3. Siliques 1 mm. wide or less; petals white, usually spatulate (4) 



4(3). Petioles of cauline leaves hirsute-ciliate at base; stems several to many 

 from the base 4. C. hirsuta. 



4. Petioles of cauline leaves naked at base; stems one or few from the base (5) 



5(4). Stem hispid or hispidulous near the base; terminal leaflet usually much 

 broader than the elliptic to obovate lateral leaflets that are notice- 

 ably decurrent on the rachis 5. C. pensylvanica. 



967 



