154 BRASSICACEAE. 



beaked or beakless; valves mostly 1 -nerved. Style slen- 

 der. Seeds in 2 rows in each cell, marginless. Cotyle- 

 dons conduplicate. 



1. D. tenuifolia (L.) DC. Annual, branched from the base, 

 sparingly hispid or glabrous, the slender branches 3-6 dm. high, 

 leafy only below; leaves oblanceolate, sinuate-lobed or sometimes 

 pinnatifid, 5-10 cm. long, narrowed at the base, mostly slender- 

 petioled; fruiting racemes long, loose; flowers 12-16 mm. broad; 

 pod about 3 cm. long, 2 mm. wide, erect, flatfish; fruiting pedicel 

 18-30 mm. long. 



Occasional along ditches about Los Angeles, Pasadena and Santa 

 Ana. Native of Europe. 



8. BRASSICA L. Mustard. 



Erect branching annual or biennial herbs, with pin- 

 natifid basal leaves, those of the stem dentate or often 

 nearly entire, and showy yellow flowers in elongated 

 racemes. Siliques elongated, sessile on the receptacle, 

 terete or 4-angled, tipped with a persistent usually 

 1-seeded beak; valves 1-3-nerved; stigma truncate or 

 2-lobed. Seeds in 1 row in each cell, globose. Cotyle- 

 dons conduplicate. 



Pods erect and appressed to the stem. 1. B. nigra. 

 Pods spreading. 



Leaves not clasping; pods pubescent. 2. B. alba. 



Upper leaves clasping; pods glabrous. 3. B. campestris. 



1. B. nigra (L.) Koch. Erect, 1-3 m. high, freely and widely 

 branching, pubescent or glabrate; lower leaves slender-petioled, 

 deeply pinnatifid, with 1 terminal large lobe and 2-4 smaller lateral 

 ones; segments all dentate; upper leaves short-petioled or sessile, 

 pinnatifid or dentate or the uppermost entire; flowers 6-10 mm, 

 broad; pedicels slender, 4 mm. long in fruit; pods narrowly linear, 

 4-angled, smooth, 10-15 mm. long, 1 mm. wide, appressed against 

 the stem; beak slender, 2-4 mm. long; seeds dark brown. 



Common in poorly cultivated fields, especially in adobe soils. 

 April-May. 



2. B. alba (L.) Boiss. Erect, branching above, 3-10 dm. high, 

 more or less pubescent with simple hairs; leaves all pinnatifid or 

 the upper only dentate; pods spreading, pubescent, tipped with 

 a flattened beak of about equal length; seeds pale yellow. 



Near the Soldiers' Home, Hasse. 



3. B. campestris L. Stems 3-10 dm. high, glabrous and glaucous 

 or rarely slightly pubescent below; lower leaves petioled, pubescent, 

 more or less lobed or pinnatifid, the upper glabrous, lanceolate or 

 oblong, acute or obtusish, sessile and clasping at the base, entire 



