306 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM, 
Fruit not winged. 
Fruit with 5 prominent ribs; involucre 
enlarged and membranous in fruit. 5. ALLIONIA (p. B34). 
Fruit smooth or somewhat 5-aungled but 
not ribbed; involucres not membra- 
nous and usually not enlarged in fruit. 
Involucre rotate, slightly enlarged 
in fruit, %-flowered ~~~ ~~ ~_____ G, ALLIONIELLA (p. 356), 
Involucres  campanulate, not — en- 
larged in fruit. 
Involueres containing several 
flowers which have a rather 
thick tube of medium length 
or sometimes rather long---— 7. QUAMOCLIDION (p. 857). 
Involucres 1-flowered. 
Perianth campanulate-- 8, HEeSPERONTA (p, 360), 
Perianth funnelform with 
a long, slender tube _____ . MIRABILIS (p. 366), 
Flowers without an involucre or each flower sub- 
tended by 1 to 3 bracts. ‘ 
Fruit with conspicuous, thin, membranous wings. 16. SELLNOCARPUS ( p. B87). 
5S 
Fruit) not conspicuously winged: wings when 
present thick and coriaceous, 
Flowers large, 2 ¢m, long or usually more. 
Perianth with a long slender tube and 
broad limb, each flower subtended by 
2 oor 8 small, narrow bracts —--- 10. ACLEISANTHES (p, 869), 
Perianth campanulate, subtended by a 
large, ovate, leaf-like bract 22 11. HerMiprum (p. 372). 
Flowers small, 2 em. long or usually much 
less, 
Fruit 10-angled or 10-ribbed. 
Fruit asymmetrical, flowers ino ra- 
cemes—— 12. SENKENBERGIA (). 372). 
Fruit symmetrical, flowers not in 
“acemes, 
Fruit with conspicuous, mucila- 
ginous glands; climbing or re- 
clining plants with thin 
leaves; flowers in umbels____ 1°. SENKENBERGIA(P. 372). 
Fruit without conspicuous 
glands: erect plants with 
very thick leaves; flowers ir- 
regularly clustered, not in 
umbels_—- 14, ANULOCAULIS (P.374). 
Fruit) 5-angled, 5-ribbed, or sometimes 
with low, thick wings: perianth cam- 
panulate 22 15, BOERHAAVIA (p. 375). 
1. ABRONIA Juss. 
Abronia Juss. Gen. 448, 1789. 
Tricratus Lo Her.; Willd. Sp. Pl. 1: S07. 1799. 
Annual or perennial herbs, erect or prostrate, glabrous or pubescent; leaves 
opposite, petioled, the blades unequal and entire; flowers few or numerous in 
the head, this surrounded by 5 or more distinet bracts: perianth colored) and 
