BRASSICACEAE. 135 



toothed or incised: sepals mostly 3-3.5 mm. long: petals 5-5.5 mm. long: 

 pods 2-2.5 cm. long, slender-beaked. — Common, on roadsides and in fields. 

 Nat. of Eu. — Spr. and sum. 



2. B. stricta Audrz. Plants similar to those of B. Barbarea in habit and 

 foliage: sepals mostly 4-4.5 mm. long: petals 5.5-6.5 mm. long: pods 2-2.5 

 cm. long, short-beaked. — Eather common, on roadsides and in fields. Nat. of 

 Eu. — Spr. 



3. B. verna (Mill.) Asch. Plants 1-6 dm. tall: leaves 2-15 cm. long; blades 

 pinnatifid, the segments toothed: sepals 8-3.5 mm. long: petals about twice 

 as long as the sepals: pods 3.5-8 cm. long. — S. Susquehanna valley. Rather 

 common, on roadsides and in waste places. Nat. of Eu. — Spr. 



13. CHEIRINIA Link. Annual or biennial herbs. Leaf -blades entire, 

 toothed, or lobed. Sepals 4, nearly equal. Petals 4, yellow, with broad blades. 

 Stamens 6; anthers oblong to sagittate. Style very short: stigma depressed. 

 Pod elongate. Seeds marginless. 



1. C. cheiranthoides (L.) Link. Stems 1-7 dm. tall, strigillose: leaf -blades 

 oblong to lanceolate or linear, 2-10 cm. long, entire, or obscurely toothed: 

 sepals 2-2.5 mm. long: petals with obovate blades about as long as the claws: 

 filaments 3-4 mm. long: pods stout-beaked. [Erysimum cheiranthoides L.] — 

 Frequent, in sandy soil, especially near streams. — Sum. — Wormseed- mustard. 



14. BEASSICA [Tourn.] L. Annual, biennial, or perennial herbs. Leaf- 

 blades lobed or pinnatifid, or those of the upper leaves entire. Sepals 4, rather 

 narrow. Petals 4, yellow or white, the blades broad. Stamens 6 : anthers 

 sagittate. Style columnar: stigma depressed or 2-lobed. Pod elongate, some- 

 times angled, the beak conic. Seeds thick, marginless. — • Mustard. 



Upper leaf -blades merely sessile : petal-blades abruptly narrowed into slender claws. 



, 1. B. nigra. 



Upper leaf-blades clasping : petal-blades gradually narrowed into 



broad blades. 2. B. campestris. 



1. B. nigra (L.) Koch. Stems 1-2 m. tall, sometimes sparingly pubescent, 

 widely branched: leaves 5-20 cm. long; blades of the lower ones lyrate- 

 pinnatifid, the terminal segment the largest: sepals becoming 4.5-5 mm. long: 

 petals 7-9 mm. long: pods 10-16 mm. long. — Common, in waste places and 

 fields. Nat. of Eu. — Spr. and sum. — Black-mustard. 



2. B. campestris L. Stems 3-6 dm. tall, glabrous and glaucous: leaves 9-30 

 cm. long, or shorter above; blades lyrate-pinnatifid: sepals becoming 4—5 mm. 

 long: petals 8-12 mm. long: pods 30-70 mm. long. — Common, in fields and 

 on roadsides. Nat. of Eu. — Spr. — Turnip. 



15. SINAPIS L. Annual or biennial herbs. Leaf-blades lobed or pin- 

 natifid. Sepals 4, herbaceous. Petals 4, mostly yellow, the blades broad. 

 Stamens 6: anthers narrowly oblong. Style columnar: stigma depressed. Pod 

 elongate, the beak sword-like. Seeds thick, marginless. 



1. S. arvensis L. Stems 3-6 dm. tall, hispid: leaves 4-17 cm. long; blades 

 of the lower ones coarsely toothed or lyrate-pinnatifid: sepals becoming 5-6 

 mm. long: petals 5.8-8.5 mm. long, the suborbicular or obovate blades ab- 

 ruptly contracted into the slender claws: pods 21-24 mm. long. — Frequent, in 

 fields and waste places. Nat. of Eu. — Spr.-fall. — Charlock. 



16. EE.UCA L. Herbs resembling Brassica and Sinapis. Leaf -blades 

 pinnatifid or some of them merely toothed, not clasping. Racemes narrow: 



