18 SPRING FLORA OF MANHATTAN. , / 



1. Capsule compressed parallel to partition. 



Linear, elongated. 



Leaves dissected, grouped near middle of stem Dentaria 



Leaves undivided; stem leafy Arabis 



Oblong; low plants Dmba 



2. Capsule terete or 4-angled. 



Short, valves convex, nerveless Enrip<t 



Valves convex or keeled, nerved; flowers very small, yellowish, 



Si.fifmbrium 

 Flowers larger; capsule beaked beyond the valves Brassica 



3. Capsule short, flattened contrary to partition. 



Obcordate Bursa 



Orbicular; stamens only 2; often apetalous Lepidium 



RORIPA, Scop. 



B. A)-moracia, (L ) The common hoi"se-radish with white flowers 

 and large leaves. Sometimes spontaneous near gardens. 



li. Nasturtium, [Li.) Rnshy. Flowers white. Capsules linear. Leaves 

 pinnate. Wet places, rare. 



B. sessilijlora, (Nutt.) Flowers yellowish, very small. Capsules 

 about 1 cm. long, nearly sessile. Leaves lyrate. Wet places, common. 



B. sinuata, (Nutt.) Flowers yellow, I cm. long. Capsules about 1 

 cm. long, on slender pedicels. Common. 



ARABIS, L 



A. Canadensis, Li. Stem i-1 m. high, leafy. Leaves oblong-laneeolate, 

 not clasping, somewhat toothed. Flowers whitish. Capsules curved, 

 elongated, very flat, pendulous. Woods, frequent. 



A. hirsnta, {L.) Scop. Leaves clasping by a sagittate base. Flowers 

 greenish. Capsules upright, straight. Rocky woods, common. 



DENTARIA, L. 

 D. laciniata, Mi\h\. Flowers white or pink; leaves 3-parted. Woods, 



rare. 



DRABA, L. 

 D. Cawliniana, Walt. Plants a few cm. high. Flowers white. 

 Leaves obovate, entire, hirsute. Capsules smooth, or in var. mirrantka, 

 (Nutt.) Gray, minutely hairy. Waste places, common. 

 SISYMBRIUM, L 

 S officinale, [L..) Scop. Leaves 1-pinnatifid. Capsules nearly sessile, 

 closely appressed to stem. A common weed. 



S. pinnatum, (Walt.) Greene. Leaves 2-pinnatifid. Cai;«nles .spread- 

 ing on horizontal pedicels. Open ground, common. 



BRASSICA, L. 



B. mgra,(l^.)Koch. Flowers bright yellow, rather large. Leaves 

 with a large terminal lobe and a few small lateral ones. Stem somewhat 

 hairy. Capsules 4-angled. Waste places, frequent. 



B. Sinapistrum, Boiss. As in B nkira, but stem smooth and 

 glaucous and leaves more or less sagittate-clasping. ( 'apsules terete and 

 knotty. Waste places, frequent. 



