CRUCIFERAE. 449 



i. Myagrum perfoliatum L. Myagrum. (I. F. f. 1699^7.) Lower leaves 

 narrowed into petioles ; upper leaves 5-13 cm. long, the basal auricles mostly 

 rounded ; pedicels 2-4 mm. Long, 2-3 times shorter than the pods ; longer stamens 

 about equalling the petals. In waste places about Quebec. Fugrtive or adventive 

 from Europe. Summer. 



12. SINAPIS L. 



Annual or biennial, usually erect, branching more or less hispid herbs, with 

 pinnatifid or lobed leaves, and rather large, mostly yellow flowers in terminal 

 racemes. Siliques linear, nearly terete, constricted between the seeds, sessile in 

 the calyx, densely hispid in our species, tipped with a very long flat sword-like 

 beak which sometimes contains a seed near its base. Seeds oblong or subglobose, 

 not winged nor margined. Cotyledons conduplicate. [Name Greek, said to come 

 from the Celtic for turnip.] About 5 species, natives of southern Europe. Only 

 the following is known from N. Am. 



I. Sinapis alba L. White Mustard. (I. F. f. 1700.) Erect, 3-6 dm. 

 high, more or less pubescent with stiff spreading hairs. Lower leaves 1.5-2 dm. 

 long, obovate in outline, deeply pinnatifid or pinnate, with a large terminal leaflet 

 or lobe and several pairs of smaller lateral ones, dentate all around ; uppermost 

 leaves lanceolate or oblong, merely dentate, short-petioled ; flowers yellow, 14-18 

 mm. broad; pedicels rather stout, spreading, 10-14 mm. long in fruit; pods spread- 

 ing or ascending, terete, constricted between the seeds ; beak flat, equalling or 

 sometimes longer than the pod ; seeds light brown. In waste places and fields, 

 occasional, mostly escaped from cultivation. Adventive from Europe. Native also 

 oi western Asia. Summer. 



13. BRASSICA L. 



Erect branching herbs, with pinnatifid basal leaves, and showy yellow flowers 

 in elongated racemes. Siliques elongated, sessile, terete or 4-sided, tipped with 

 an indehiscent conic usually i-seeded beak. Valves convex, 1-3-nerved. Seeds 

 in 1 row in each cell, oblong, marginless; cotyledons conduplicate. [Latin name 

 of the Cabbage.] About 80 species, natives of Europe, Asia and northern Africa. 



None of the leaves clasping the stem, the upper sessile. 



Pods slender, 1-2.5 cm - l° n gi appressed. 1. B. nigra. 



Pods rather slender, 2-5 cm. long, erect, not appressed, on slender pedicels 6-10 mm. 

 long. 



Leaves merely toothed or lyrate-pinnatifid. 2. B. juncea. 



Leaves laciniate, at least marginally. 3. B.Japonica. 



Pods spreading or ascending at maturity, on stout pedicels 4-6 mm. long. 



4. B. arvensis. 

 Upper leaves clasping by an auricled base. 5. B. campestris 



1. Brassica nigra (L.) Koch. Black Mustard. (I. F. f. 1701.) Erect, 

 0.5-2.1 m. high, freely branching. Lower leaves slender-petioled, with I terminal 

 large lobe and 2-4 smaller lateral ones, dentate all around, the uppermost reduced 

 to lanceolate or oblong entire blades; flowers bright yellow, 6-10 mm. broad; pedi- 

 cels slender, appressed, 4 mm. long in fruit; pods narrowly linear, 4-sided, I— 1 .5 

 cm. long, 1 mm. wide, appressed; beak slender, 2-4 mm. long; seeds dark brown 

 In fields and waste places, common throughout our area. Nat. from Europe 

 June-Nov. 



2. Brassica juncea (L.) Cosson. Indian Mustard. (I. F. f. 1702.) Pale, 

 glabrous, or slightly pubescent, somewhat glaucous; stem erect, 3-12 dm. tall. 

 Lower leaves long-petioled, 1-1.5 dm. long, the uppermost sessile or nearly so, 

 lanceolate or linear, commonly entire, much smaller; flowers 1. 2- 1.8 cm. wide; 

 pedicels 6-10 mm. long, not appressed; pods 2-5 cm. long, rather more than 2 mm. 

 wide, the conic-subulate empty beak one-fourth to one-third the length of the 

 body. In waste places, N. H. to Penn., Mich., Va. and Kans. Adventive or 

 nat. from Asia. May-July. 



3. Brassica Japonica Siebold. Similar to the preceding, but the leaves 

 laciniate. sometimes deeply so, often much crisped. In waste places, Me. to Ga. 

 Adventive from Asia. 



