NYCT AGIN ACE AE (FOUR-O'CLOCK FAMILY) 175 



Perennials; fruit coriaceous, the narrow wings not encircling the fruit. 

 Flowers white, 2-3 cm. long. 



Leaves glabrous; fruit-wings narrow . . . . . 1. A. fragrans. 



Leaves puberulent; fruit-wings broad . . . . . . 2. A. salsa. 



Flowers greenish, 2 cm. or less long. 



Involucral bracts 4-5 mm. long; fruit biturbinate . . ... 3. A. ammophila. 



Involucral bracts 7-15 mm. long; fruit turbinate . . . .4. A. elliptica. 

 Annuals; wings of fruit broad, orbicular, net-veined. 



Wings of fruit double; terminating above in disks . . . . 5. A. Carletonii. 

 Wings of fruit single; ^completely encircling it. 



. 7. A. cycloptera. 



Prostrate; wings of fruit emarginate . . . . . . 6. A. micrantha. 



Erect; wings of fruit entire ....... 



1. Abronia fragrans Nutt. Hook. Kew Journ. Bot. 5: 261. 1853. From 

 nearly glabrous and somewhat glaucous to moderately white-hirsute and 

 viscid; perennial, with branched ascending or erect stems, 2-6 dm. high: 

 leaves from oval to oblong-elliptic, obtuse, the base rounded or cuneate, 

 3-7 cm. long: involucral bracts ovate-oblong or obovate, 1-2 cm. long: flowers 

 very numerous, white, 2-3 cm. long: fruit coriaceous, with 2-5 narrow wings. 

 From Montana to New Mexico and eastward to the Missouri. 



la. Abronia fragrans glaucescens A. Nels. Bot. Gaz. 34: 364. 1902. Stems 

 glabrous at least below, slightly puberulent and viscid toward the inflores- 

 cence: leaves glabrous, pale green above and more or less glaucous beneath: 

 fruit terminating in a conical beak one third as long as the narrowly winged 

 obconical body. Northern Colorado to Montana and westward to Oregon. 



2. Abronia salsa Rydb. Bull. Torr. Bot. Club 29: 684. 1902. Resembling 

 the preceding, but densely viscid-pubescent especially above, and with very 

 evident puberulence on the oval or elliptic leaves: bracts rounded obovate, 

 15 mm. long: flowers many, 2 cm. long; the limb 4 mm. broad: fruit cuneate- 

 obpyramidal, 8 mm. long, 6 mm. broad including the rather thick wing. 

 (A.fallax Heimerl, Rydb. 1. c.) Western Colorado and Utah. 



3. Abronia ammophila Greene, Pitt. 4: 226. 1900. Glandularrpuberulent 

 throughout: stems decumbent or prostrate, 2-4 dm. long: leaves oblong- 

 elliptic, obtuse: involucral bracts membranous, oblong, acute, 4-5 mm. long: 

 flowers numerous, greenish or ochroleucous: fruit tapering to both ends, with 

 about 5 low and rounded crests, densely glandular-pubescent. (A. pumila 

 Rydb. Bull. Torr. Bot. Club 29: 683. 1902.) On the sandy beaches of Yel- 

 lowstone Lake. 



4. Abronia elliptica A. Nels. Bull. Torr. Bot. Club 26: 7. 1900. Glabrous 

 except for a minute viscid puberulence upon the stems and inflorescence; 

 stems decumbent at base, assurgent-erect, 1-3 cm. long: leaves elliptic or 

 ovate, obtuse, the base rounded or subcordate: involucral bracts mostly 

 obovate, obtuse or acutish, 7-15 mm. long: flowers greenish-white, numerous, 

 15-20 mm. long: fruit obscurely pubescent, turbinate; wings usually 5, narrow, 

 with rounded obtuse summits. (A. Bakeri Greene, PL Baker. 3: 32. 1901; 

 A. glabra Rydb. Bull. Torr. Bot. Club 29: 685. 1902.) Desert areas; Wyom- 

 ing and northern Colorado and Utah. 



5. Abronia Carletonii Coult. & Fish. Bot. Gaz. 17: 349. 1892. Stems pro- 

 cumbent, slender, whitish, minutely glandular, 2.5-4 dm. long: leaves very 

 thick, linear-oblong or oblong-ovate, with cuneate base and revolute mar- 

 gins: peduncles very slender, as long as the leaves: involucral bracts 5, rose- 

 color, oblong-lanceolate, attenuate or cuspidate, 6 mm. long: flowers nu- 

 merous: perianth rose-color, with obcordate lobes: fruit longer than broad, 

 scarcely coriaceous, with the 5 wings coarsely reticulated and terminating 

 above in disks. Eastern Colorado. 



6. Abronia micrantha (Torr.) Chois. in DC. Prodr. 13 2 : 436. 1849. Annual, 

 prostrate: peduncles shorter than the petioles: flowers small and inconspicu- 

 ous, reddish-green, the limb scarcely 4 mm. broad: fruit with 3 thin wings, 

 emarginate above and below, the body rather broad and with a light spongy 

 exterior. On sandy plains; Montana to New Mexico. 



7. Abronia cycloptera Gray, Am. Journ. Sci. II. 15: 319. 1853. Annual, 

 stouter: flowers large and showy, upon elongated peduncles: fruit with firmer 

 and more prominently veined wings, emarginate at neither end, the firm 



