Flora of the Palousc Region 83 



Pubescence of simple hairs. 



Leaves pinnatifid into rather large irregular segments. 



S. OFFICINAL}.. 

 Leaves pinnatifid in nearly equal linear segments. vS. A.I/TISSIMUM. 

 Pubescence of forked hairs. 



Leaves tripinnate. S. sophia. 



Leaves pinnatifid or bipinnatifid. S. incisum. 



S. officinale Scop. Erect, sparsely hirsute, with simple hairs or glabrous, 

 30-90 cm. high, divaricately branched above: leaves pinnatifid into 5-13 lobes, 

 the terminal longest, all more or less dentate: upper cauline leaves sessile, 

 the others petioled: flowers yellow, 3 mm. broad: pods tapering from the 

 base to the apex, 1-2 cm. long, erect on short pedicels. A weed in waste 

 ground. 



S. altissimum L. Erect, much branched, .6-1.5 m - tall, glabrous or 

 sparsely hirsute, with simple hairs: basal leaves petioled, pinnatifid, in lin- 

 ear or lanceolate entire or dentate lobes; upper leaves reduced, sessile: flow- 

 ers yellow, 5 mm. broad: pod spreading, linear, 6-10 cm. long on short stout 

 pedicels. Introduced along railroads: a dangerous weed. 



S. Sophia L. Erect, much branched above, .3-1 in. tall, canescent 

 throughout with short stellate pubescence: leaves tripinnatifid, 5-S cm. long, 

 the segments linear or oblong, small: racemes elongated: pods glabrous, 

 1.5-2 cm. long, curved upwards, on slender shorter pedicels: seeds in one 

 row in each cell of the pod. Sparingly introduced. 



S. incisum var. filipes Gray. Stem slender, erect or ascending, sparingly 

 branched, usually minutely stellate-pubescent: leaves pinnatifid or bipin- 

 natifid; segments of the lower leaves oblong, of the upper ones narrowly 

 linear, usually elongate and entire: racemes loose: pods 10-15 mm. long, 

 acute, usually curved, ascending, on slender longer pedicels. Very common 

 on open hillsides: variable. 



130. BRASSICA. 



Erect annual or biennial herbs: lower leaves mostly pinnate or 

 lyrate, with a large terminal lobe: flowers yellow : pod terete or 

 nearly so, tipped with a slender conical or somewhat flattened 

 beak; seeds globose, in one row or rarely in two rows in each cell. 



Upper leaves clasping the stem: smooth. B. camprstris. 



None of the leaves clasping the stem: hispid. B. SINAPISTRUM. 



B. campestris L. Smooth or nearly so, often glaucous, 30-90 cm. high: 

 lower leaves petioled, somewhat lobed or toothed; upper entire or nearly so, 

 sessile and clasping by auricled bases: flowers yellow; pedicels spreading: 

 petals 6-10 mm. long: pods terete, 3-5 cm. long, narrowed into a beak about 

 1 cm. long. Grain fields and waste places: sometimes a troublesome weed. 



B. sinapistrum Koiss. Stout, annual, 30-90 cm. high, hispid with scat- 

 tered hairs: lower leaves pinnately parted, consisting of a large ovate-ob- 

 long terminal segment and 1 or 2 pairs of much smaller ones, all dentate; 

 uppermost leaves sessile, none clasping: pods 2-4 cm. long, erect or ascend- 

 ing, the fertile portion torulose, the beak flat and stout. A weed in waste 

 ground. 



