CRUCIFERAE (MUSTARD FAMILY) 227 



5. Arabis recondita Greene, Pitt. 4: 195. 1900. Perennial, green and 

 glabrous above, minutely stellate-pubescent below: stems few to many, only 

 1-2 dm. high: basal leaves obovate to oblanceolate, dentate, narrowed to a 

 petiole which is ciliate with simple hairs or hairs forked at summit: calyx 

 stellate-pubescent: petals rose-purple: siliques glabrous, 3-4 cm. long, spread- 

 ing, slightly curved: seeds imperfectly biserial. Western Colorado to Arizona. 



6. Arabis Lemmonii Wats. Proc. Am. Acad. 22: 467. 1887. Perennial, 

 glabrous and glaucous above, finely hoary stellate-pubescent below: stems 

 few to several from the caudex, 1-2 dm. high: basal leaves obovate or oblong- 

 spatulate, entire, rather thick, short-petioled ; cauline oblong-lanceolate: se- 

 pals pubescent: petals rose-color: siliques ascending or spreading, broadly 

 linear, 2-3 cm. long; the valves faintly nerved to the middle: seeds in 1 row, 

 narrowly winged. From northwestern Wyoming to far northwest. 



7. Arabis rugocarpa Osterh. Bull. Torr. Bot. Club 31: 357. 1904. Per- 

 ennial, more or less purple-tinged throughout, hispid-ciliate and obscurely 

 pubescent with branched hairs: stems few to several, spreading, only 1-2 dm. 

 high: basal leaves oblanceolate, acute or acuminate, 2-3 cm. long; cauline 

 auriculate, small, oblong: petals purple, fully twice as long as the spatulate 

 scarious-margined sepals: siliques rugose, 1-nerved, 2-3 cm. long, reflexed, 

 on pedicels about 5 mm. long: seeds in 1 row, margined but not winged. 

 W T estern Colorado. 



8. Arabis oxylobula Greene, Pitt. 4: 195. 1900. Much like the preceding, 

 nearly glabrous: stems few from the short branched caudex, 1-2 dm. high: 

 basal leaves narrowly oblanceolate, sparingly hispid-ciliate at base; cauline 

 oblong, sessile, not auricled, about 1 cm. long: siliques linear, straight, about 

 2 cm. long, spreading or a little deflexed on short filiform pedicels; the valves 

 1-nerved: seeds imperfectly biserial. (A. demissa Greene, PI. Baker. 3: 8. 

 1901.) Western Colorado. 



9. Arabis microphylla Nutt. T. & G. Fl. N. A. 1: 82. 1S3S. Perennial, 

 softly stellate-pubescent, especially below: stems several to many from the 

 freely and slender-branched caudex, 2-4 dm. high: basal leaves crowded, 

 linear or nearly so, with petioles often ciliate; cauline few, similar: sepals 

 generally glabrous: petals pale rose-color: siliques narrowly linear, somewhat 

 curved and spreading, 4-6 cm. long, on filiform pedicels about 1 cm. long: 

 seeds small, in 1 row. (.4. densicaulis A. Nels. Bot. Gaz. 30: 190. 1900.) 

 Utah, northwestern Wyoming to Oregon. 



10. Arabis fructicosa A. Nels. Bot. Gaz. 30: 190. 1900. Biennial, glabrous 

 and glaucous, except for a little fine stellate pubescence at base: stems sev- 

 eral from the enlarged crown of the taproot, each simple or somewhat branched 

 above, very leafy below, 4-8 dm. high: radical leaves not persisting the second 

 year; cauline short, 1-2.5 cm. long, elliptic-oblong to ovate, more or less 

 toothed, subauricled: petals white or purplish: siliques linear, divaricate, 

 ascending, 4-6 cm. long, on slender pedicels 6-8 mm. long: seeds in 1 row, 

 not margined. Yellowstone Park. 



11. Arabis Nuttallii Robinson, Syn. Fl. 1: 160. 1895. Perennial, with short 

 branching caudex, more or less hirsute, with simple or forked hairs: basal 

 leaves spatulate-oblanceolate, acute or obtuse, petioled, 2-3 cm. long; cauline 

 mostly oblong, sessile (not auricled): flowers white: siliques 1-nerved, ob- 

 scurely veined, erect, less than 2 cm. long, on ascending pedicels often as long 

 as the silique. A. spathulata. Wyoming and Montana and far westward. 



12. Arabis hirsuta Scop. Fl. Cam. Ed. 2. 2: 30. 1772. Biennial, more or 

 less hispidly hirsute or ciliate: stem erect, solitary or several from the base, 

 leafy, 2-5 dm. high: basal leaves obovate to spatulate, dentate or repand, on 

 margined petioles, 3-5 cm. long; cauline sessile, auriculate, from oblong to 

 linear, suberect, coarsely toothed or entire: flowers white: siliques erect, 

 usually very numerous and fascicled, linear, 3-5 cm. long: seeds narrowly 

 margined, imperfectly biseriate. Frequent in our range; across the continent; 

 also in Europe and Asia. 



13. Arabis Crandallii Robinson, Bot. Gaz. 28: 135. 1899. Caespitose 

 perennial, hoary puberulent throughout, with minute stellate hairs: stems nu- 



