CRUCIFERAE (MUSTARD FAMILY) 209 



as the sepals. Stamens not exserted. Ovary sessile; style short. Silique 

 slender, terete. Sisymbrium in part. 



1. Schoenocrambe linifolia (Nutt.) Greene, Pitt. 3: 127. 1896. Glabrous 

 and green : stems from running rootstocks, one or more from each node, erect, 

 simple or at length somewhat branched above: leaves all cauline, linear, en- 

 tire, or the lower sometimes somewhat incised and oblanceolate : silique 3-6 cm. 

 long, linear, suberect, on short spreading pedicels; style short; seeds oblong. 

 Sisymbrium linifolium. (S. decumbens Rydb. Bull. Torr. Bot. Club 31: 409. 

 1904.) Northern Colorado to Montana and westward. 



la. Schoenocrambe linifolia pinnata (Greene) A. Nels. Glabrous and glau- 

 cous throughout : stems always simple, nearly leafless above : the lower leaves 

 rather numerous, pinnatifid into 5-8 pairs of obovate-oblong entire segments. 

 (S. pinnata Greene, 1. c.) Range of the species. 



3. THELYPODIUM Endl.* 



Mostly biennial herbs (rarely perennial), with alternate petioled or clasp- 

 ing stem leaves and white, purple, or yellow flowers. Calyx cylindric or clavate 

 in bud, spreading in flower. Petals flat, long and narrow or with claw and 

 blade. Filaments long and slender; anthers linear, sagittate at base, curved 

 or coiled. Stigma small, circular in outline, or very slightly 2-lobed. Silique 

 slender, terete, or 4-angled, often torulose. 



Biennials. 



Flowers white or purple. 

 Stem leaves not clasping. 



Sessile; siliques numerous, short 1. T. integrifolium. 



Petioled; siliques few, long. 



Siliques erect, on spreading pedicels . . . . . 2. T. linearifolium. 



Siliques widely spreading, on divaricate or deflexed pedicels 3. T. Wrightii. 

 Stem leaves clasping by a cordate or sagittate base. 



Lanceolate to linear, acute . . . . . . . 4. T. torulosum. 



Ovate or ovate-lanceolate, acute . . . . . . 5. T. elegans. 



Flowers yellow; leaves ovate, acute 6. T. aureum. 



Perennials. 



Glabrous or glabrate . . . . . . . . . 7. T. paniculatum. 



More or less stellate-pubescent 8. T. micranthum. 



1. Thelypodium integrifolium Endl. Walp. Rep. 1: 172. 1842. Glabrous, 

 erect, more or less branched, usually simple at base, 4-12 dm. high: radical 

 leaves petioled, oblong or elliptical; cauline lanceolate, sessile, the uppermost 

 nearly linear : inflorescence usually corymbosely branched ; flowers pale rose- 

 color, very crowded-spicate, on divaricate pedicels: siliques sharp-pointed, 

 somewhat nodulose, suberect or upwardly curved, very uniform, 2-3 cm. 

 long. From Colorado and Nebraska to the Pacific. 



la. Thelypodium integrifolium gracilipes Robinson Syn. Fl. 1: 176. 1895. 

 Racemes more elongated, becoming 1 dm. or more in length: siliques borne 

 upon a slender stipe 2-3 mm. long. (T. lilacinum Greene, PI. Baker. 3: 9. 

 1901.) Southwestern Colorado. 



2. Thelypodium linearifolium Wats. Bot. King's Rep. 5: 25. 1871. Glabrous 

 biennial (rarely perennial), more or less branched, sometimes from the base: 

 basal leaves incisely serrate, obovate, early deciduous; cauline leaves linear 

 to linear-oblong, narrowed to the short petiole-like base: flowers somewhat 

 scattering: petals with obovate blade and slender claw, rose-purple: silique 

 suberect, 4-7 cm. long, on very slender spreading pedicels. Colorado and 

 southward. 



3. Thelypodium Wrightii Gray, PL Wright. 1: 7. 1852. Glabrous annual 

 or biennial, 5-8 dm. high, more or less paniculately branched above: leaves 

 broadly lanceolate or lanceolate-oblong, 5-10 cm. long, all repand toothed or 



* This genus has recently been the subject of some discussion, and Rydberg has pro- 

 posed the following doubtfully distinct segregates: Thellypodiopsis, Pleurophragma, Hes- 

 peridanthus, Stanleyella, and Heterothrir. For species included under each, see Bull. Torr. 

 Bot. Club 34: 432. 1904. 



ROCKY MT. BOT. 14 



