45 FLORA. 



4. Brassica arvensis (L.) B. S. P. CHARLOCK. WILD MUSTARD. (I. F. f. 

 1703.) Erect, 3-6 dm. high, hispid with scattered stiff hairs, or glabrate. Leaves 

 similar to those of B. nigra but generally not so much pinnatifid; flowers 1-1.6 

 cm. broad; pedicels stout; pods glabrous, spreading or ascending, somewhat con- 

 stricted between the seeds, 1-1.6 cm. long, 2 mm. wide, tipped with a flattened 

 elongated-conic often i-seeded beak 10-12 mm. long, the valves strongly nerved. 

 In fields and waste places, frequent or occasional. Adventive from Europe. May 

 Nov. \B. Sinapistrum Boiss.] 



5. Brassica campestris L. TURNIP. WILD NAVEW. (I. F. f. 1704.) Stem 

 3-9 dm. high, glabrous and glaucous, or sometimes slightly pubescent. Lower 

 leaves petioled, pubescent, more or less lobed or pinnatifid; upper leaves lanceo- 

 late or oblong, sessile and clasping by an auricled base; glabrous; flowers bright 

 yellow, 8-10 mm. broad; pedicels spreading or ascending, often 2.5 cm. long in 

 fruit; pods 3-5 cm. long, tipped with a beak 8-10 mm. long. In cultivated 

 grounds, sometimes persisting for a year or two, and occasional in waste places. 

 Fugitive from Europe. April-Oct. 



Brassica Niipus L. (RAPE) has all the leaves glabrous, and is sometimes found in 

 waste places. 



Brassica oler^cea L. (CABBAGE) is occasionally found in waste places. 



14. DIPLOTAXIS DC. 



Herbs similar to the Mustards, with pinnatifid or lobed leaves, and rather large 

 yellow flowers in terminal racemes. Silique elongated, linear, flat or flattish, 

 short-beaked or beakless, the valves mostly i-nerved. Style usually slender. 

 Seeds in two complete or incomplete rows in each cavity of the silique, margiriless; 

 cotyledons conduplicate. [Greek, referring to the double rows of seeds.] About 

 20 species, natives of the Old World, the following fugitive or adventive in our 

 territory. 



Perennial; stem leafy nearly to the inflorescence. i. D. tenuifoha. 



Annual; leaves mostly basal, oblanceolate. 2. D, muralis. 



1. Diplotaxis tenuifolia (L.) DC. WALL ROCKET. (I. F. f. 1705.) Gla- 

 brous or nearly so, somewhat glaucous; stem bushy, 312 dm. high. Leaves 

 pinnatifid, thin, the lower 7-15 cm. long, the lobes mostly narrow; flowers 1.5-2 

 cm. broad; pods 2-3 cm. long, about 2.5 mm. wide, nearly erect; pedicels slender, 

 2-4 cm. long in fruit. In waste places and ballast, N. S. to N. J. and Penn. 

 Adventive from Europe. June-Aug. 



2. Diplotaxis muralis (L.) DC. SAND ROCKET. (I. F. f. 1706.) Branched 

 from the base, sparingly hispid or glabrous, leafy only below. Leaves oblanceo- 

 late, sinuate-lobed or pinnatifid, 5-10 cm. long, narrowed at the base, mostly 

 slender-petioled; flowers 12-16 mm. broad ; pod about 2.5 cm. long and 2 mm. 

 wide, erect, flattish; fruiting pedicels 8-16 mm. long. In waste places and 

 ballast, range of the preceding. Adventive from Europe. June-Aug. 



15. RAPHANUS L. 



Mainly biennial herbs, with lyrate leaves and showy flowers. Silique elongated - 

 linear, coriaceous, fleshy or corky, constricted or continuous and spongy between 

 the seeds, indehiscent. Style slender. Seeds subglobose; cotyledons conduplicate. 

 [Greek, quick-appearing, from its rapid germination.] A genus of about 6 

 species, natives of Europe and temperate Asia. 



Flowers yellow, fading white; pod longitudinally grooved, 4-io-seeded. 



1. R. Raphanistnim. 

 Flowers pink or white; pod not longitudinally grooved, 2-3-seeded. 



2. R. sativus. 



i. Raphanus Raphanistrum L. WILD RADISH. JOINTED OR WHITE 

 CHARLOCK. (I. F. f. 1707.) Biennial or annual from a slender root, 3-7.5 dm. 

 high, sparsely pubescent or rarely glabrous. Basal and lower leaves lyrate-pin- 

 natifid, 1-2 dm. long, with a large terminal lobe and 4-6 pairs of successively 

 smaller lateral ones, all crenate or dentate; upper leaves small, oblong; flowers 

 1-2 cm. broad, yellow, fading to white, purplish-veined; pedicels 6-16 mm. long 



