1 84 CRUCIPERAE. 



pod 1 in. long or less, the lower segment cylindrical, the upper ovoid and 

 acuminately narrowed to a flattened truncate often retuse beak. 



Sea beaches near San Francisco: West Berkeley; Black Point; near Lake 

 Merced. Introduced. June-Sept. 



5. BRASSICA L. Mustard. 



Annuals, either glabrous or sparsely hispid with coarse hairs, the lower 

 Leaves usually lyrately pinnatifid or pinnate, the upper disposed to be more 

 or less entire. Flowers large, yellow. Lateral sepals more or less gibbous 

 at base. Petals with long claw and abruptly spreading limb. Papilla-like 

 glands 4, green, alternating with the claws of the petals. Pod terete, terminat- 

 ing in a stout beak; valves 1 to several-nerved. Seeds in 1 row, globose. Cotyle- 

 dons conduplicate, incumbent. (The Latin name for cabbage. All of our 

 species naturalized weeds.) 



Pods terete, commonly 1 in. long or more, on ascending or spreading pedicels. 



Beak terete; stem-leaves auriculate-clasping 1. B. campestris. 



Beak 2-edged, often 1-seeded, much shorter than the body; stem-leaves petioled, or the 



upper merely sessile, none auriculate-clasping 2. B. arvensis. 



Pods somewhat quadrangular, closely appressed to the axis of the raceme, Yz to j£ in. 

 long ; leaves all petioled 3. B. nigra. 



1. B. campestris L. "Common Yellow Mustard." Erect, sparingly 

 branched, 1 to 6 ft. high; herbage succulent, glaucous, and glabrous save for 

 some bristle-bearing pustules on the upper surface of the lower leaves; cauline 

 leaves all sessile and clasping by an auricled base; lower leaves irregularly 

 serrate or denticulate, and pinnatifid or pinnate with the terminal segment 

 very large and the lateral segments sessile by a broad base and more or less 

 decurrent on the rachis; upper cauline lanceolate and entire; flowers 6 to 8 

 lines broad; sepals narrowly oblong, yellowish, ascending; petals with elliptic 

 blade; pods terete, l 1 ^ to 1% in. long, narrowed into a subulate beak, tipped 

 with a flat stigma. 



Very common. Feb. -Apr. It is the Turnip of the gardens run wild. 



2. B. arvensis (L.) B.S.P. Charlock. Herbage light green, hispid with 

 scattered hairs; leaves pinnatifid with a large shallowly lobed terminal 

 segment and usually a pair of much smaller angular segments on the rachis, 

 or ovate or triangular-ovate and lobed or denticulate; upper leaves deltoid- 

 ovate to ovate-lanceolate, petioled or sessile by a narrow base, not clasping; 

 petals 4 to 6 lines long; pods ascending or erect, 1 to 1% in. long, with 3 to 8 

 seeds in each cell; beak flattish, % as long as the body, often containing a 

 seed; valves nerved. — (B. sinapistrum Boiss.) 



Western Alameda Co.; abundant in alfalfa fields at Yreka, Butler. Apr. 



3. B. nigra (L.) Koch. Black Mustard. Dark green (not glaucous), 

 nearly glabrous or with some scattered stiff hairs, 3 to 6 or even 12 ft. high; 

 leaves all petiolate; lower lyrately pinnatifid or divided; terminal segment very 

 large, shallowly lobed and sharply dentate ; upper leaves less lobed or the upper- 

 most linear and entire and commonly drooping or pendulous; racemes long 

 and dense; petals 3^ lines long, much longer than the sepals; pods closely 

 appressed to the axis of the raceme, torulose, indistinctly 4-sided, beaked by 

 the style; seeds nearly black, highly pungent. 



Everywhere common. Very abundant in interior grainfields. May-July. 



6. RAPHANUS L. Eadish. 



(ciarse much-branched animals or biennials. Lower leaves lyrately pinnate or 

 pinnatifid, shortly petioled. Flowers large, purple or yellow, or becoming white. 



