RUBIACEAE. 



365 



1. Borreria laevis (Lam.) Griseb. But- 

 ton-weed. (Fig. 396.) Slightly pubescent, 

 branched, the branches spreading or ascend- 

 ing, 6'-18' long, somewhat angled. Leaves 

 oblong to elliptic-lanceolate, i'-lV long, 

 acute or acuminate at the apex, narrowed at 

 the base into short petioles, pinnately 

 veined; stipular sheath subtruncate, bearing 

 several bristles 2"-3" long; flowers white, 

 about li" wide, capitate-clustered in the 

 axils; calyx-lobes 4, ovate, minute; fruit 

 obovoid, about 1" long; seeds oblong, stri- 

 ate. [Spermacoce laevis Lam.] 



Common in nearly all dry situations. Na- 

 tive. West Indies. Flowers nearly through- 

 out the year Its minute seeds were probably 

 brought to Bermuda on the wind. 



7. SPERMACOCE L, 

 Annual or perennial herbs, the stems 

 usually 4-angled, the leaves opposite; stip- 

 ules sheathing. Flowers perfect, solitary or few in the axils. Calyx-lobes per- 

 sistent, sometirhes accompanied by small teeth. Corolla white, pink or blue, 

 funnelform or salverform, the lobes spreading, valvate. Stamens 4, adnate 

 to the throat of the corolla-tube or lower down. Ovary 2-celled; styles wholly 

 or partially united, filiform; ovules solitary in each cavity, attached to the 

 middle of the septa, amphitropous. Fruit leathery or crustaceous, of two car- 

 pels, one opening through the ventral face, the other remaining closed. [Greek, 

 seed-point, from the sharp calyx-teeth surmounting the capsule.] About 4 



species, natives of temperate and 

 tropical America. Type species: 

 Spermacoce tenuior L. 



Plant glabrous or nearly so ; leaves 

 linear to oblong-lanceolate l"-3" 

 wide. 1. S. tenuior. 



Plant pubescent with long hairs ; 

 leaves lanceolate, 4"-10" wide. 



2. 8. tetraquetra. 



1. Spermacoce tenuior L. 



Slender Spermacoce. (Fig. 397.) 

 Glabrous or nearly so. Stems 

 simple and erect or more or less 

 diffusely branched from the base, 

 the branches 4'-12' long; leaves 

 linear, oblong or oblong-lanceolate, 

 j'-2' long, acute or acuminate at 

 both ends, narrowed into short 

 petioles; calyx-lobes subulate or 

 lanceolate-subulate ; corolla white, 

 twice or thrice as long as the calyx- 

 lobes, its lobes broad, rounded, the 

 fruit about 1" long. 



Waste and cultivated grounds 

 Naturalized. Native of temperate 

 and tropical America. Flowers from 

 spring to autumn. 



