176 RUBIACE^E. (MADDER FAMILY.) 



and slender ; fruit ovoid, strongly ribbed, crowned with the 2 (rarely 4) linear 

 or lanceolate calyx-teeth. (D. tetragona, Walt. D. hirsuta, Pursh.) Wet 

 places, Florida to North Carolina, and westward. June - Sept. Stem 1 - 4 

 long. Flowers white or purplish. 



2. D. teres, Walt. Annual ; stem erect, widely branched from the base, 

 terete, bristly or hairy ; leaves linear or lanceolate, acute, rough ; flowers soli- 

 tary or 2 - 3 together ; corolla funnel-shaped ; fruit obovate, even, crowned with 

 the 4 short calyx-teeth. (Spermacoce diodina, Michx.) Dry sandy soil, Flor- 

 ida to Mississippi, and northward. July -Sept. Stem 6' -12' high, some- 

 times prostrate. Flowers purplish. 



5. ERNODEA, Swartz. 



Calyx ovate ; the limb 4 - 6-parted, persistent. Corolla salver-shaped, slender ; 

 the lobes 4-6, re volute. Stamens exserted; anthers linear, erect Style slen- 

 der, longer than the stamens. Fruit obovate, somewhat fleshy, the two separa- 

 ble horny carpels closed. Seeds furrowed on the inner face. A somewhat 

 shrubby prostrate and smooth plant, with rigid 3-nerved lanceolate leaves, and 

 solitary sessile axillary flowers. 



1. E. littoralis, Swartz. South Florida, along the coast. March and 

 April. Stems straight, rigid, 4-angled, smooth. Branches short, alternate. 

 Leaves sessile, smooth, acute, the upper ones crowded. Flowers sessile in the 

 upper axils, yellow. Fruit roundish. 



6. CEPHALANTHUS, L. BUTTON-BUSH. 



Calyx obconical, 4-toothed. Corolla tubular, 4-clcft, imbricated in the bud. 

 Stamens 4. Style slender, exserted. Stigma capitate. Fruit diy, obconical, 

 separating from the base into 2-4 one-seeded carpels. Seeds pendulous. Albu- 

 men horny. Aquatic shrubs, with oval or lanceolate leaves, short entire sti- 

 pules, and white flowers collected into a globose long-peduncled head. Recep- 

 tacle hairy. 



1. C. OCCidentalis, L. Smooth, or the young branches and lower sur- 

 face of the ovate-oblong acute leaves pubescent ; peduncles terminal, and in the 

 upper axils. Ponds and marshes, Florida, and northward. July and August. 

 Stem 4 -12 high. Leaves petioled, 3' - 5' long, sometimes 3 in a whorl. 

 Heads 1' in diameter. 



7. MITCHELLA, L. 



Flowers by pairs, with their ovaries united. Calyx 4-toothed. Corolla fun- 

 nel-shaped, 4-lobed, hairy within, valvate in the bud. Stamens 4. Style slen- 

 der. Stigmas 4. Fruit composed of two 4-seeded fleshy drupes united, crowned 

 with the 4-toothed calyx. A smooth creeping evergreen shrub, with small 

 broadly-ovate leaves, minute stipules, and fragrant white terminal flowers. 



1. M. repens, L. Shady woods, Florida to Mississippi, and northward. 

 March and April. Stem l-2 long. Leaves 6" -10" long, mostly some- 

 what cordate, shining above, on slender petioles. Corolla ^' long. Fruit red. 



