216 CRUCIFERAE (MUSTARD FAMILY) 



1. Roripa Nasturtium (L.) Rusby, Mem. Torr. Club 3: 5. 1893. A glabrous 

 aquatic with decumbent stems rooting at the nodes, often 4-5 dm. high: 

 leaves pinnate or pinnately lobed; the leaflets or lobes sinuate, the terminal 

 one larger: racemes crowded, elongating in fruit: petals white, twice as long 

 as the sepals: silique linear, as long as the divaricate pedicels; style very 

 short. Nasturtium officinale. WATER CRESS. Naturalized in many ponds 

 and streams. 



2. Roripa sinuata (Nutt.) A. S. Hitch. Spring Fl. Manhattan 18. 1894. 

 Glabrous perennial, spreading by horizontal slender rootstocks: stems nu- 

 merous, diffuse, branched, 2-3 dm. long: leaves oblong or lanceolate, sinuately 

 pinnatifid; the lobes obtuse or acute, entire or toothed: flowers yellow: siliques 

 linear, tipped with the long style, becoming curved, as also the slender ped- 

 icel. From New Mexico to Montana and west to the Sierras. 



3. Roripa hispida (Desv.) Brit. Mem. Torr. Club 5: 169. 1894. Hispidly 

 hirsute with spreading hairs on the stem and on the veins of the leaves below : 

 stem usually simple below, more or less branched above, 3-10 dm. high: 

 leaves lyrate-pinnatifid, the lower petioled: flowers yellow, on slender pedi- 

 cels: silique globose to narrowly ovate, rarely more than twice as long as broad, 

 and shorter than the spreading pedicel. In wet places; not infrequent in our 

 range, and widely distributed throughout the United States. 



4. Roripa palustris (L.) Bess. Enum. 27. 1821. Very similar but usually 

 lower, sometimes branched from the base, glabrous or obscurely pubescent, 

 never hirsute or hispid: silique narrowly ovate to nearly linear, 2-4 times as 

 long as broad, about equaling the pedicels. (R. Underwoodii Rydb. Bull. 

 Torr. Bot. Club 29: 235. 1902.) Approximately the same range as the pre- 

 ceding. 



5. Roripa curvisiliqua (Hook.) Bessey, Mem. Torr. Club 5: 169. 1894. 

 More or less minutely pubescent, usually branched from the base but erect, 

 1-2 dm. high: leaves narrowly oblong or oblanceolate, pinnatifid with oblong 

 usually toothed lobes, rarely only sinuate-toothed : petals pale yellow, surpas- 

 sing the sepals: silique linear, curved upwardly, about 1 cm. long, on spread- 

 ing pedicels half as long; stigma sessile or subsessile. From Colorado and 

 Wyoming to British Columbia. 



6. Roripa lyrata (Nutt.) Rydb. Mem. N. Y. Bot. Card. 1: 176. 1900. 

 Glabrous, branched from the base and spreading: leaves lyrately deeply 

 divided; the lobes broad but variously toothed and incised: flowers small: 

 silique nearly straight, tapering slightly toward the apex which terminates 

 abruptly in the short style, 8-12 mm. long, twice as long as the pedicels. 

 Includes R. obtusum alpinum and R. sphaerocarpa. In the mountain dis- 

 tricts of our range and northwestward. 



7. Roripa curvipes Greene, Pitt. 3: 97. 1896. Low, slender, diffusely 

 branched, the branches in maturity ending in several elongated racemes which 

 are unilateral by the decurved pedicels of the very small pods: herbage nearly 



tlabrous: leaves from lyrate-pinnatifid to ovate-lanceolate and merely dentate: 

 owers minute, yellow in all parts, the petals slightly surpassing the sepals: 

 stamens not exserted: pods ovate-acuminate or ovate-falcate, scarcely 4 mm. 

 long, tipped by a short style, few-seeded, often torulose by one or more man- 

 ifest constrictions. " Rather frequent in the mountains of southern Colorado, 

 at middle elevations, along streamlets chiefly." 



13. CARDAMINE L. BITTER CRESS 



Mostly glabrous herbaceous perennials, growing in wet places, with running 

 rootstocks or small tubers, petioled, simple or pinnate leaves, and white or 

 purple racemed flowers. Sepals equal at base. Petals obovate to spatulate. 

 Siliques linear, straight, with stout replum and nerveless valves. Seeds in 

 1 row. 



Leaves entire, broad, and somewhat cordate. 



Stem glabrous . . . . . . . . . . 1. C. cordifolia. 



Stem hirsute . 2. C. infausta. 



