106 BRASSICACEAE 



Leaves spatulate or broadly oblanceolate, thick. 40. D. crassa. 



» Plant decidedly hairy. 



Pubescence long-hirsute, with simple or slightly branched hairs. 



41. D. streptocarpa. 

 Pubescence short, mostly of stellate or branched hairs. 



Styles 1.5-2 mm. long; pods glabrous or slightly puberulent. 



Pod not twisted; pubescence rather sparse or minute; stem-leaves 

 usually sharply toothed. 

 Stem more or less hirsute. 42. D. spectabilis. 



Stem minutely appressed-stellate. 43. D. oxyloba. 



Pod twisted; pubescence dense and grayish; stem-leaves entire- 

 margined or minutely denticulate. 44. D. Helleriana. 

 Style 1 mm. long; pods densely pubescent. 

 Stem erect or nearly so. 



Leaves tliin, the basal ones usually over 2 cm. long, the cauline 

 ovate to lanceolate. 

 Petals 5 mm. or more long. 



Petals pale yellow; stem-leaves often dentate. 



45. D. luteola. 

 Petals bright yellow; stem-leaves entii-e-margined. 



46. D. surculifera. 

 Petals 3—4 mm. long, pale yellow; stem-leaves entire-mar- 

 gined. 47. D. aureiformis. 



Leaves thick, the basal ones oblanceolate, 1-2 cm. long, the 

 cauhne lanceolate or oblong. 48. D. aurea. 



Stem decumbent. 



Leaves finely stellate; pods twisted. 49. D. decumbens. 



Leaves coarsely hairy, with branched hairs; pods not twisted. 



50. D. brachystylis. 



40. ARABIS L. Rock Cress, Wild Candytuft. 



Basal leaves Ij-rately lobed; perennials. I. Lyr.it.ve. 



Basal leaves entire-margined or toothed. 

 Pods erect or nearly so. 

 Leaves coarsely hirsute. 



Stem-leaves neither cordate nor auricled at the base. II. Furcatae. 

 Stem-leaves cordate or auricled at the base; biennials. 



III. HiRSUTAE. 



Leaves not coarsely hirsute; perennials. 



Pubescence, if any, sparse and consisting of 2-forked or rarely 3-forked hairs. 



IV. Drltvemondlvj^ae. 

 Pubescence of at least the lower leaves decidedly stellate. 



V. MlCROPHYLL.\E. 



Pods spreading or reflexed. 



Pods and caly.x stellate. VI. Pulchr.\e. 



Pods not stellate. 



Pods 3-4 mm. wide. VII. Suffrutescentes . 



Pods 1-2.5 mm. wide. 



Pods spreadmg or somewhat recurved on spreading pedicels. 



Pods only 1-1.5 mm, wide. VIII. Macounianae. 



Pods 1.5-2.5 mm. wide. 



Perennials, with a caudex. 



Plant tall, 3 dm. or more high, suffruticose at the base. 



IX. Perenn antes. 

 Plant low, 1-2 dm. high, cespitose. X. Reconditae. 



Stout biennials or short-lived perennials, 3 dm. liigh or more. 



XI. Arcu.vtae. 

 Pods and pedicels reflexed. XII. Retrofractae 



I. Lyr.\tae. 

 Pods about 0.75 mm. wide; style more than 0.5 mm. long. 1. A. lyrata. 



Pods fully 1 mm. wide; style almost obsolete. 2. A. ambigua. 



II. Furc.\t.\e. 



Seeds not winged; leaves hairy; pods 1 mm. wide or less. 3. A. Nuttallii. 



Seeds winged at the lower end; leaves merely ciliate on the margins; pods 1.5-2 mm. wide. 



4. A. furcata. 



III. Hirsut,\e. 



All sepals narrowly oblong; two of them with slightly saccate bases; petals 3-5 mm. long, 

 yellowish white, less than twice as long as the sepals. 5. A. orata. 



Two of the sepals wath strongly saccate bases, almost twice as broad as the others; petals 

 6-10 mm. long, pure white, fully twice as long as the sepals. 6. A. rupestris. 



IV. Drummondianae. 

 Stems 3 dm. high or more, solitary or 2 or 3 from the same root. 



Pods about 1.5 mm. wide. 7. A. Drummondit. 



Pods about 3 mm. broad. 8. A. connexa. 



Stems less than 3 dm. high, several from a cespitose caudex. 



Pods strictly erect, blunt. 9. A. alherUna. 



Pods rather ascending, acute. 10. A. Lyalln. 



