MUSTARD FAMILY 269 



long; siliques erect or merely ascending, mostly curved, 1.5-2.5 cm. long, less than 1 mm. 

 broad, linear, acute at apex; septum 2- or sometimes 3-nerved; seeds in one row. 



Introduced weed, more common in Canada, eastern Oregon, and Washington, and the Great Basin region, 

 and occurring more sparingly in the eastern part of California as far south as San Diego County. Type 

 locality: Europe. May- Aug. 



2. Descurainia Richardsonii subsp. viscdsa (Rydb.) Detling. Mountain 



Tansy-mustard. Fig. 2002. 



Sophia viscosa Rydb. Bull. Torrey Club 29: 238. 1902. 



Descurainia Rydbergii O. E. Schulz, Pflanzenreich 4 105 : 319, in part. 1924. 



Descurainia Richardsonii subsp. viscosa Detling, Amer. Midi. Nat. 22: 492. 1939. 



Annual herb 4-8 dm. high branching above the base, the branches ascending, more or less 

 pubescent throughout. Leaves thin, 5-10 cm. long, bipinnate or the cauline pinnatifid or bipinnati- 

 fid, with broad lobes; inflorescence glandular; fruiting racemes often congested; pedicels 4-9 

 mm long, ascending, or the lower ones divaricately spreading; flowers yellow; sepals 1.5-1.8 

 mm. long; petals slightly surpassing the sepals; siliques 8-15 mm. long, glabrous, ascending or 

 sometimes erect, rarely divaricately spreading, on same axis as pedicel, acute at base and apex 

 and tipped by style 0.5 mm. or more long; seeds dark, in one row, 1-1.3 mm. long. 



Dry pine and fir forests, Canadian Zone; Cascade Mountains, Washington, south to the Sierra Nevada of 

 California and east to the Rocky Mountains. Type locality: Beaver Canyon, Idaho. June-Sept. 



Descurainia Richardsonii var. macrosperma O. E. Schulz, Pflanzenreich 4 10B : 319. 1924. Plants non- 

 glandular, essentially glabrous; fruiting pedicels but slightly spreading and siliques closely appressed to the 

 axis of the inflorescence. Central Rocky Mountain area and occasional in the Sierra Nevada, California. 

 Sophia frocera Greene and Sisymbrium Hartivegianum of authors, not Fourn. are here considered synonyms of 

 the variety. 



Descurainia Richardsonii subsp. incisa (Engelm.) Detling, Amer. Midi. Nat. 22:494. 1939. (.Sisym- 

 brium incisum Engelm. in A. Gray, PI. Fendl. 8. 1849.) Plants more or less pubescent, non-glandular; fruit- 

 ing pedicels spreading, siliques on same axis as the pedicel or ascending. At high elevations, southern Montana 

 south to Chihuahua, Mexico, and through the Sierra Nevada and mountains of southern California to the 

 Sierra San Pedro Martir, Lower California, Mexico. 



3. Descurainia californica (A. Gray) O. E. Schulz. Sierra 

 Tansy-mustard. Fig. 2003. 



Smelowskia californica A. Gray, Proc. Amer. Acad. 6: 520. 1865. 



Sophia Sonnet Greene, Pittonia 3: 95, as to description, not synonymy. 1896. 



Sophia leptostylis Rydb. Bull. Torrey Club 39: 325. 1912. 



Descurainia californica O. E. Schulz, Pflanzenreich 4 103 : 330, as to name only. 1924. 



Annual herbs, 5-8 dm. high, the stems branching above the base, herbage green. Leaves thin, 

 scantily pubescent, pinnate, the upper often pinnatifid with broad obtuse lobes; inflorescence 

 compact, glabrous, flowers yellow, pedicels ascending, 2.5-5 mm. long; siliques ascending or 

 erect, 3-5 mm. long, appressed to axis of inflorescence, acute at both ends, tipped by style 5 mm. 

 or more long ; seeds about 1 mm. long, in one row. 



Arid Transition and Boreal Zones; the crest of the Sierra Nevada of California east to the southern moun- 

 tain ranges of the Great Basin region and south to northern Arizona and New Mexico. Type locality: Mono 

 Lake, California. July. 



4. Descurainia obtusa subsp. adenophora (Woot. & Standi.) Detling. 

 Desert Tansy-mustard. Fig. 2004. 



Sisymbrium Cumingianum Robinson in A. Gray, Syn. Fl. N. Amer. I 1 : 139. 1895. Not Fisch. & Mey. 1835. 

 Sophia adenophora Woot. & Standi. Contr. U.S. Nat. Herb. 16: 127. 1913. 

 Descurainia obtusa subsp. adenophora Detling, Amer. Midi. Nat. 22: 498. 1939. 



Coarse canescent-tomentose thick-leaved annual, 6-15 dm. high, branching above the base, the 

 branches ascending. Lower cauline leaves 5-14 cm. long, coarsely bipinnatifid, the segments 

 obtuse, the upper 2-5 cm. long, pinnate with lobes oblong to oblong-lanceolate; inflorescence 

 many-flowered, glandular-pubescent throughout, petals pale yellow, slightly exceeding the 

 sepals ; pedicels spreading, nearly equaling the erect or ascending siliques ; siliques slightly pu- 

 bescent to glabrate, linear, acute, 12-19 mm. long; seeds less than 1 mm. long, obscurely ar- 

 ranged in 2 rows. 



Upper Sonoran Zone; San Jacinto and San Bernardino Mountains of southern California, east to New 

 Mexico. Type locality: northwestern Grant County, New Mexico. May-June. 



5. Descurainia pinnata subsp. Menziesii (DC.) Detling. Western 



Tansy-mustard. Fig. 2005. 



Cardamine Menziesii DC. Syst. 2: 267. 1821. 



Sisymbrium canescens var. californicum Torr. & Gray, Fl. N. Amer. 1: 92. 1838. 

 Descurainia Menziesii O. E. Schulz, Pflanzenreich 4 105 : 328. 1924. 

 Descurainia pinnata subsp. Menziesii Detling, Amer. Midi. Nat. 22: 508. 1939. 



Annual herbs, canescent throughout to nearly glabrate, 1-4 dm. high, simple or much 

 branched from the base. Leaves bipinnate or bipinnatifid, divided into many elliptic or linear- 

 oblong segments, 1-3 cm. long; inflorescence glandular to glabrate; flowers many, greenish 

 yellow or nearly white, 2 mm. or less long ; petals barely exceeding sepals ; pedicels widely di- 

 vergent, often at right angles to rachis, 8—15 mm. long; siliques usually curved, slightly ascend- 



