422 



CRUCIFERAE QMUSTAKD FAMIL.^^ 



Petals white. 



Valves of pod conspicuously keeled 



Valves of pod rounded or flat. 



Pods terete 



Pods more or less flattened 



h. Hairs at least in part branched. 



Stigma obtusely cone-shaped ; petals purple, 15-20 mm. long . 



Stigma otherwise ; petals smaller. 



I Pods terete or 4-angled, sometimes torulose. 



Tall, 6-12 dm. high ; pods 8 cm. long 



Not over 3 dm. high ; pods shorter. 



Annual ; pods not torulose 



Perennial ; pods more or less torulose 



Pods decidedly flattened. 

 Pods lanceolate to narrowly oblong, rarely over 13 mm. in length 

 Pods linear, when normal and mature 15-SO mm. long . • 



18. Alliabia. 



23. 



Radicula. 



CAUDAMItTR 



21. Hespbkis. 



31. Arabis. 



19. SiSTMBKICM. 



20. Braya. 



1. Draba. 

 31. Arabis. 



T31. D. verna. 

 Part of fruiting 

 raceme X %. 

 Petal X U/a. 



1. DRABA [Dill.] L. 



Pod oval, oblong, or even linear, flat ; the valves plane or slightly convex ; 

 the partition broad. Seeds several or numerous, in 2 rows in each cell, 

 marginless. Cotyledons accumbent. Filaments not toothed. — 

 Low" herbs with entire or toothed leaves, and white or yellow 

 flower.s; pubescence often stellate. (Name from Spd/^Tj, applied 

 by Dioscorides to some cress ; meaning unknown.) 



^h §1. ER6pHILA (DC.) Reichenb. Animal or biennial ; flowers 



J white, cleistog anions ; petals 2-cleft. 



/ 1. D. VERNA L. (Whitlow Grass.) Small (scapes 2.5-8 cm. 



high) ; leaves all radical, oblong or lanceolate ; racemes elongated in 

 fruit ; pods varying from round-oval to oblong-lanceolate, smooth, 

 shorter than the pedicels. — Sandy waste places and roadsides, 

 e. Mass. to Minn, and southw. — A species remarkable as an 

 aggregate of many closely related forms w^hich, from their cleis- 

 togamy, seldom cross or intergrade Apr., May. (Nat. from 

 Eu.) Fig. 731. 



§ 2. DRABELLA DC. Winter annuals ; leafy stems short; leaves oblong or 

 obovate, hairy, sessile; petals entire or merely emarginate^ white {yellow in 

 no. 4); style none. 

 2. D. caroliniana Walt. Small (2.5-12 cm. high) ; pedun- 

 cles scape-like ; petals usually twice the length of the calyx ; 

 raceme short or corymbose in fruit (1.2-2.5 cm. long); pods 

 broadly linear, smooth, much longer than the ascending pedi- 

 cels.— Sandy and waste fields, e. Mass. to Minn., Neb., 

 and southw. March-May. Fig. 782.— Petals often wanting 

 in the later racemes, especially in the var. micr antra (Nutt.) 

 Gray, with minutely rough-hairy pods, 

 which is found with the other, w^estw^ 



3. D. cuneifblia Nutt. Leaves obovate, 

 wedge-shaped, or the lowest spatulate, 

 toothed ; raceme somewhat elongated in 

 fruit (2.5-7.5 cm.), at len.gth equaling the 

 naked peduncle; petals emarginate, much 

 longer than the calyx ; pods oblong-linear, 

 minutely hairy, longer than the spreading 

 pedicels. — Grassy places, Ky., 111.? to e. 

 Kan., southw., and southwestw. March, 

 Apr. Fig. 733. 



4. D. brachycarpa Nutt. Low (5-10 

 cm. high), minutely pubescent; stems 

 leafy to the base of the dense at length 



734. D. brachycarpa. elongated raceme ; leaves (4-8 mm. long) 

 Inflorescence X 2/3. narrowly oblong or the lowest ovate, few- 



732. D. caroliniana. 

 Fruiting raceme X Vs- 

 Fruit with valves re* 

 moved x \y^. 



738. D. cunelfolla. 

 Fruiting raceme x «/» 



