1 18 CRUCIFERAE. 



Erysimum asperum (Nutt.) DC. Whitish throughout with appressed 

 pubescence; stems simple, stout, 20-40 cm. tall, erect; leaves lanceolate or 

 oblanceolate, entire or somewhat dentate, rarely lobed, mostly petioled, 6-10 

 cm. long; flowers bright yellow; petals 15-25 mm. long; pods stout, somewhat 

 4-anglecl, about 8 cm. long, tipped with a short stout beak and a large 2-lobed 

 stigma; pedicels stout, 1 cm. long. Common in stony soil. 



Erysimum elatum Nutt. Similar to E. asperum but taller, with sparse 

 closely appressed pubescence; leaves all entire or nearly so, lanceolate or the 

 .lowest oblanceolate, 5-10 cm. long; seeds lenticular. On rocky banks, Blue 

 Mountains. 



162. 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. 



Cauline leaves auricled at base and clasping. B. campestris. 



Cauline leaves not auricled or clasping. 



Beak of the pod very short, less than one-fourth the seed- 

 bearing part. B. nigra. 

 Beak of the pod long, at least half as long as the seed-bearing 



part. B. arvensis. 



Brassica campestris I.. Turnip. Smooth or nearly so, often glaucous, 

 3090 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 

 a beak about 1 cm. long. Grain fields and waste places; sometimes a trouble- 

 some weed. 



Brassica nigra (L.) Koch. Black Mustard. Erect, 30-80 cm. high, sparsely 

 hirsute; leaves green, slender-petioled, the terminal lobe large and coarsely 

 toothed, the few lateral lobes small; pods 15-18 mm. long, erect, on very short 

 pedicels, only the lower fourth seed-bearing; seeds dark-colored. In waste 

 places. 



Brassica arvensis (L.) B.S.P. Charlock. Stout, annual, 30-90 cm. high, 

 hispid with scattered hairs; lower leaves pinnately parted, consisting of a 

 large ovate-oblong terminal segment and 1 or 2 pairs of much smaller ones, all 

 dentate; uppermost leaves sessile, none clasping; pods 24 cm. long, erect or 

 ascending, the fertile portion torulose, with a beak flat and stout and half as 

 long. A weed in waste ground. 



163. RADICULA. 



Aquatic or marsh herbs; leaves usually lyrately or pinnately 

 parted or toothed, auricled at base; flowers small, yellow or white; 

 style short or slender; pods terete or nearly so; seeds turgid, 

 minute, in two rows in each cell. 



Flowers white. R. nasturtium-aquatica. 



Flowers yellow. 



Plant perennial by rootstocks. R. sinuata. 



Plants annual or biennial, without rootstocks. 



Pedicels 6-8 mm. long; stems erect. R. pacifica. 



Pedicels 2-4 mm. long; stems diffuse. 



Pods curved; leaf-lobes acute. R. curvisiliqua. 



Pods straight; leaf-lobes obtuse. R. obtusa. 



