Vol. 111.] 



MADDER FAMILY. 



217 



5. SPERMACOCE L,. Sp. PI. 102. 1753. 



Herbs, with 4-sided stems, opposite pinnately veined stipulate leaves, and small white 

 flowers, in dense axillary and terminal clusters. Calyx-tube obovoid or obconic, its limb 4- 

 toothed. Corolla funnelform, 4-lobed. Stamens 4, inserted on the tube of the corolla; 

 anthers oblong or linear. Ovary 2-celled; ovules 1 in each cavity; style slender; stigma 

 capitate, or slightly 2-lobed. Capsule coriaceous, didymous, of 2 dehiscent carpels, or one 

 dehiscent, the other indehiscent. Seeds oblong, convex on the back; endosperm horny; 

 embryo central; cotyledons foliaceous. [Greek, seed-point, from the sharp calyx-teeth sur- 

 mounting the carpels.] 



Two species, natives of America. 



i. Spermacoce glabra Michx. Smooth 

 Button-weed. (Fig. 3405.) 



Spermacoce glabra Michx. Fl. Bor. Am. i: 82. 1803. 



Glabrous, decumbent or ascending, rather stout; stems 

 io / -20 / long. Leaves lanceolate or elliptic-lanceolate, 

 petioled, or the uppermost sessile, x'-if long, 4 // -i2 // 

 wide, acute at each end, the margins rough; corolla 

 pubescent in the throat, about i^'long, scarcely exceed- 

 ing the ovate-lanceolate acute calyx teeth; stamens and 

 style included; capsule obovoid, about 1" long, glabrous; 

 seeds black, punctate. 



On river-banks and in wet soil, southern Ohio and Ken- 

 tucky to Florida and Texas. Also in tropical America. 

 June-Sept. 



6. DIODIA L,. Sp. PI. 104. 1753. 



Decumbent or ascending branching herbs, with opposite, mostly sessile, entire conspicu- 

 ously stipulate leaves, and small axillary white lilac or purple flowers. Calyx tube obconic 

 or obovoid, the limb 2-4-lobed (sometimes 1-6-lobed), often with minute teeth between the 

 lobes. Corolla funnelform or salverform, mostly 4-lobed. Stamens usually 4, inserted on 

 the throat of the corolla; filaments slender; anthers versatile, oblong-linear, exserted. 

 Ovary 2-celled (rarely 3-4-celled); ovules 1 in each cavity; style filiform, simple, or 2-cleft; 

 stigmas 2. Fruit crustaceous or somewhat fleshy, oblong, obovoid, or subglobose, 2-celled, 

 finally separating into 2 indehiscent carpels. Seed oblong, convex on the back; endosperm 

 horny; cotyledons foliaceous; embryo straight. [Greek, thoroughfare, where the species 

 are frequently found.] 



About 35 species, mostly American. Besides the following, another occurs in the southern States. 

 Leaves linear-lanceolate; style entire; stigmas capitate. 1. D. teres. 



Leaves lanceolate or oval; style 2-cleft; stigmas filiform. 2. D. Virginiana. 



i. Diodia teres Walt. Rough Button-weed. 

 (Fig. 3406.) 



Diodia teres Walt. Fl. Car. 87. 1788. 

 Spermacoce diodina Michx. Fl. Bor. Am. 1: 82. 1803. 



Rigid, usually rough, much branched from near the 

 base, the branches prostrate or ascending, 4-sided 

 above, 4 / ~30 / long. Leaves linear or linear-lanceo- 

 late, very rough, Yi'-iYz' long, l%"-2f f wide, acute, 

 the margins revolute when dry; flowers lilac or pur- 

 ple, 2 // -3 // long, usually solitary in the axils; style 

 entire; stigmas capitate; fruit obovoid or top-shaped, 

 hispid, about 1" high, the usually 4 persistent calyx- 

 lobes ovate to lanceolate. 



In dry or sandy soil, Connecticut to Florida, west to 

 Illinois, Missouri, Texas, New Mexico and Sonora. 

 July-Sept. 



