DiODiA. RUBIACE^. ^ 29 



fleshy, crowned with the teeth of the calyx, 2- (rarely 3-) celled ; the 2 (or 3) 

 one-seeded carpels separating from the apex downwards, both indehiscent. 

 Seeds oval, peltate, flattish, marked with a shallow furrow on the face. — 

 Herbaceous or rarely suffrutescent plants (American, but chiefly tropical), 

 with the habit of Spermacoce. Leaves often fascicled in the axils, so as to 

 appear verticillate. Stipules usually fringed with bristles. Flowers small, 

 white, axillary, solitary or several together. 



* Corolla somewhat hypocrateriform, toitk a long and very slender tube : style deeply 2- 

 cleft ; fruit crowned with 2 {or 4 alternately smaller') calyx-teeth. 



1. T>. Virginiana (Linn.) : perennial, herbaceous ; stem procumbent ; 

 leaves varying from lanceolate-linear to oblong-lanceolate, sessile ; bristles of 

 the stipules longer than the sheaths ; flowers solitar}^ opposite ; tube of the 

 corolla 3 or 4 times the length of the calyx-teeth, tubular, the liinb abruptly 

 expanded; stamens exserted ; lobes of the deeply 2-cleft style filiform ; fruit 

 ovoid or oblong, coriaceous, crowned with 2 (rarely 4 alternately smaller) 

 lanceolate calyx-teeth. 



a. Linnrei : nearly glabrous ; leaves lanceolate ; fruit oblong, somewhat 

 glabrous. — D. Virginiana, Linn. spec. 1. p. 104; Lam. ill. t. 63. D. Vir- 

 ginica, Willd. spec. 1. p. 58 (excl. syn. Walt.) ; Pursh, fl. I. p. 105 ; Ell. 

 sk. 1. p. 190 ; DC. prodr. 4. p. 562. Spermacoce Virginiana, A. Rich. 

 mem. I. c. t. 4,/. 3. 



(i. latifolia : somewhat pubescent ; leaves ovate-lanceolate ; fruit ovate, 

 hairy. — D. Virginica, Michx.lji. \. p. 81. D. tetragona, Walt. Car. p. 

 87 ; Ell. sk. l.V- 190 ; DC. I. c. 



y. hirsuta : whole plant very hairy ; leaves linear-lanceolate, very acute ; 

 fruit oblong— D. hirsuta, Pursh, f. l- p- 106 ; Ell sk. I. p. 191 ,• DC I. c. 



Damp soil, particularly along rivers, a. Sf li. Virginia I to East Florida! 

 Alabama and Louisiana ! y. South Carolina, Elliott. Georgia, Pursh, 

 Middle Florida, Dr. Chapman! May-Oct. — Stem 1-2 feet long, somewhat 

 quadrangular. Leaves 1-2 inches long: in /3. those of the branches much 

 shorter and broader in proportion than the lower cauline ones ; in y. nearly 

 all of equal length. Flowers nearly half an inch long. Corolla white ; the 

 segments lanceolate-oblong, more or less hairy inside. Anthers linear. 

 Capsule 2-3 lines long in a. and ji., 4-5 lines in y., marked with several 

 strong longitudinal ridges. Seed oblong, plano-convex. Embryo nearly as 

 long as the albumen : colyledons oblong : radicle inferior, slender. — We find 

 so many intermediate forms between D. Virginica, tetragona, and hirsuta of 

 authors, that we can scarcely distinguish them even as varieties. 



* * Corolla infundibuliform, vnth a loicle tube : style undivided : stigma capitate or 2- 

 lobed : fruit crowiied loith 4 (^rarely 5) calyx-teeth. 



2. D. teres (Walt.) : annual, ascending or procumbent ; stems pubescent 

 or hairy ; leaves linear or linear-lanceolate ; bristles of the stipules much 

 longer than the fruit ; flowers solitary or 2-3 in each axil ; corolla much 

 longer than the minutely serrulate-ciliate calyx-teeth; the stamens shorter 

 than its lobes ; stigma large, 2-lobed ; fruit somewhat hairy, ovoid-turbinato 

 and somewhat quadrangular, separating into 2 crustaceous carpels. — Walt. 

 Car. p. 87; DC.! prodr. 4. j}- 562 ; Darlingt.fl. Cest. p. 104. Spermacoce 

 diodina, Michx. ! fl. I. p. 82 ; Pursh, fl. I. p. 85 ; Ell. sk. 1. p. 189 ; Torr. t 

 fl.l.p.170. 



Sandy fields. New Jersey! to Florida! and Louisiana! and west to Illi- 

 nois! and the sources of the Cantidian River, Dr. James ! Aug.-Sept . 



Stem nearly terete, 4-16 inches high, much branched, clothed with a short 



