NYCTAGINACEAE (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. fragrana. 



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. 



Involiicral bracts7-15 mm. lon^; 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. 



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



Erect; wings of fruit entire , , . 7. A. cycloptera. 



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

 nearly glal^rcus and somewhat glaucous to njodei'ately white-hirsute and 

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

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

 3-7 cm. long: involucral bracts pvate-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 tp 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 elUptic leaves: bracts rounded obovate, 

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

 obpjrramidal, 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. Glandular-puberulent 

 throughout: stem^ 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. BuU. 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-wlute, numerous, 

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

 with roimded obtuse smnmits. (A. Bakeri Greene, PI. Baker. 3: 32. 1901; 

 A. 5r?o6m Rydb. -Bull. Torr. Bot. Olub 29: 685. 1902.)— Desert areas; Wyom- 

 ing and northern Colorado and Utah. 



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

 cumbeit, 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 m disks. — Eastern Colorado. 



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

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

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

 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 



