604 CONTRIBUTIONS FROM THE NATIONAL HEEBAEIUM. 



KEY TO THE GENERA. 



Carpels 1-seeded. 



Stipules foliaceous, resembling tlie leaves, the leaves 

 thus appearing whorled; stems 4-sided; corolla 



rotate 1. Galium (p. 604). 



Stipules more or less connate-sheathing, lacerate, the 

 leaves distinctly opposite; stems not con- 

 spicuously 4-sided; corolla salverform 2. Cbusea (p. 606). 



Carpels se^^eral to many-seeded. 



Seeds winged; corolla long- tubular, bright red; leaves 

 broadly lanceolate, 2 to 5 cm. long; ovules and 



seeds numerous 3. Bouvardia (p. 606). 



Seeds not winged; corolla short, salverform, never 

 bright red; leaves narrower, mostly less than 

 2 cm. long; ovules and seeds several. 

 Top of the capsule extending beyond the hypan- 



thium 4. HousTONiA (p. 607). 



Top of the capsule not exceeding the hypan- 



thium 5. Oldenlandia (p. 608). 



1. GALIUM L. Bedstraw. 



Low annual or perennial herbs with 4-angled stems and small whorled leaves, 

 the stipules often as large as the leaves; flowers small, perfect, white, yellowish, or 

 pm-ple, in axillary or terminal cymes or panicles; sepals often obsolete; corolla rotate, 

 \vith 3 or usuallj' 4 lobes; ovary 2-celled, with one ovule in each cell; styles 2; stigmas 

 capitate; fruit of 2 nearly separate, 1-seeded cai'pels, either glabrous or hispid, dry 

 or fleshy. 



KEY TO THE SPECIES. 



Fruit covered with long straight hairs. 



Corolla purplish, the lobes abruptly long-acuminate. 



Leaves linear or linear-oblong, nearly glabrous; stems 



puberulent 1. G. rothrochil. 



Leaves oblanceolate or elliptic, strongly pubescent; 



stems birtellous 2. G. wrightii. 



Corolla white or yellowish; petals obtuse or merely acute. 



Leaves ovate to elliptic-lanceolate, thick, fleshy 3. G. acutissimuvi. 



Leaves linear-oblong, thin 4. G. fendleri. 



Fruit glabrous or covered with hooked hairs. 



Fruit scaberulous to glabrous, never with hooked hairs. 



Leaves acute; bracts persistent at the base of the fruit. . 5. G. micro phy Hum. 



Leaves obtuse; fruit not bracteate 6. G. brandegei. 



Fruit covered with hooked hairs. 



Stems stout, erect; leaves 3-nerved 7. G. boreale. 



Stems slender, weak, usually reclining; leaves mostly 

 1-nerved. 



Leaves not cuspidate-pointed; slender annual 8. G. proliferum. 



Leaves cuspidate-pointed; annuals or perennials. 

 Pedicels scarcely exceeding the bracts; stout 

 plants, usually annuals. 



Leaves Linear or oblanceolate 9. G. apartne. 



Leaves elliptic 10. G. Jlaviflorum. 



Pedicels much exceeding the bracts; perennials. 

 Leaves broadly elliptic; corolla yellowish; 



stems nearly smooth 11. G. Iriflorum. 



Leaves narrowly oblong; corolla puiplish; 



stems very rough 12. G. asperrlmum. 



