346 BRASSICACEAE 



31. BRASSICA L. Cabbage, Rape, Turnip, Black Mus 



Annual, biennial, or perennial herbs, caulescent, with alternate leaves. Flow- 

 ers perfect, in elongate racemes or panicles. Sepals ascending, equal or the 

 outer somewhat saccate at the base. Petals yellow or white, clawed. Filaments 

 free, unappendaged. Pods elongate, linear, terete or somewhat 4-angled, with 

 an elongate-conic seedless beak, the valves 1-3-nerved; stigma truncate or 2- 

 lobed. Seeds in one row in each cell, subglobose, marginless. Cotyledons con- 

 duplicate. 



None of the leaves clasping. 



Pod slender. 4-angled, erect, appressed to the stem. 1. B, nigra. 



Pod ascending, terete, but with a strong midvein. 2 B juncca. 



Upper stem-leaves clasping. ' 



Leaves glaucous, all glabrous except the very earliest ones; petals cream-colored, 



long-clawed. 3. b, campestris, 



-Leaves not glaucous, the basal ones distinctly hairy; petals bright yellow, short- 



cla-wed. 4, B. Rapa. 



1. B, nigra (L.) Koch. Annual; stem 5-20 dm. high, branching, glabrous 



or nearly so; lower leaves pinnatifid, with a large rounded or oval terminal lobe 



and a few small lateral ones; uppermost leaves lanceolate or oblong, entire; 



sepals yellowish; petals bright yellow, spatulate, 7-8 mm. long; pod 1.5-2 cm. 



long, a httle over 1 mm. thick; beak slender. Black Mustard. Waste places 



and fields: Me.— Fla.— Calif.— B.C.; W. Ind.; nat. fiom Eu. Plain— Submont. 

 Ap-S. 



2. B, juncea (L.) Cosson. Annual or biennial (?); stem erect, 3-12 dm. 

 high, branched, glabrous or nearly so; lower leaves 1-1.5 dm. long, lyrate-pinnat- 

 md with a large oval dentate end lobe, the upper lanceolate or linear; petals 

 vellow, 8-10 mm. long, broadly spatulate; pod 3.5-5 cm. long, 2-3 mm. thick; 

 beak 5-8 mm. long. Fields and waste places: N.S.— Va.— N.M,— Sask.; adv. 

 or nat, from Asia. Plain — Submont, Jl-S. 



3. B. campestris L. Annual or biennial; stem 3-10 dm. high, glabrous; 



basal leaves lyrate-pinnatifid, with a large toothed end lobe; stem-leaves lanceolate, 



entire; petals cream-colored, spatulate, 6-7 mm. long; pod 5-7 cm. long, about 



3 mm. thick; beak about 1 cm. long. Rape, Rutabaga, Swedish Turnips. 



Fields and waste places: N.S.— Mont.— Colo.; escaped from cultivation. Plain 

 — Submont. Ap-0. 



4. B. Rapa L. Annual or biennial, closely resembUng the preceding, 

 but greener and more hairy, and with smaller and bright yellow flowers. Tuhnip. 

 Wjaste places: west to Wyo. and Mont.; escaped from cultivation. Plain. Ap^ 



32. ATHYSANUS Greene. 



Small annuals, branched near the base, with toothed or pinnatifid leaves. 

 Flowers perfect, minute in elongate racemes. Sepals ovate-rounded, spread- 

 mg, equal at the base. Petals minute, linear, or wanting. Stamens subequal, 

 with slender filaments. Anthers short. Fruit orbicular, 1-celled, 3-4-ovuled, 

 but 1-seeded, wingless, covered with uncinate hairs. 



1. A. pusillus (Hook.) Greene. Dehcate annual; stem branched near the 



base, pubescent with branched hairs; leaves oblanceolate or obovate, toothed, 



8-15 cm. long, stellate; petals white, spatulate, 1.5 mm. long, or in the later 



flowers usually wanting; fruiting pedicels recurved, 2-3 mm. long; pod orbicular, 



2-2.5 mm. broad, hirsute. Dry prairies and hills: Calif.— Ida.— B.C. Son.— 

 oubmont, F-My, 



33. THYSANOCARPUS Hook. 



Slender caulescent annuals, with alternate leaves. Flowers perfect, in slender 

 racem^. Sepals ovate, rounded, spreading. Petals spatulate, white or purplish. 

 Stamens subequal, with slender filaments. Pods orbicular, 1-celled, 1-ovuled, 

 1-seeded, mdehiscent, winged, the wing often toothed on the margins Uke a cog- 

 wheel or perforated by round holes near the margins; style slender, but short. 

 Pubescence of simole hairs or nnnp 



