RUBIACEAE (MADDER FAMI;.y) 751 



ters or heads. (Name compounded of airipiia^ 

 seed, and ukuik-^, a point, probably from the pointed 

 calyx-teeth on the fruit.) 



1. S. glabra Michx, Glabrous perennial; 

 stems spreading, 2-5 dm. long ; leaves oblong- 

 lanceolate ; heads many-flowered ; corolla little 

 glabra. exceeding the calyx, bearded in the throat, 



bearing the anthers at its base ; filaments and 



style hardly any. — River-banks, s. O. to 111., Ark., Tex., and Fla. Aug. 



Fig. 911. 



5. DI6dIA [Gronov.] L. Buttonweed 



Calyx-teeth 2-5, often unequal. Fruit 2(rarely 3)-celled, the crustaceous 

 carpels into which it splits all closed and indehi.scent. Flowers l-;3 in each 

 axil. — Resembling Spermacoce. Flowering all summer. (Name from 5to5os, 

 a thoroughfare; the species often growing by the wayside.) 



1. D. virginiana L. Smooth or hairy perennial; stems spreading, 3-6 dm. 

 long ; leaves lanceolate or oblong-lanceolate, sessile ; corolla white, 1 cm. long, 

 the slender tube abruptly expanded into the 



large limb ; style 2-parted ; fruit ellipsoid, 

 strongly furrowed^ crowned mostly with 

 2 slender cal} x-teeth. — Low grounds along 

 streams, s. N. J. to Fla., w. to Mo., Ark., 

 and Tex. Fig. 912. 



2. D. teres Walt. Hairy or minutely 

 pubescent annual ; stem spreading, 1-8 dm. 

 long, nearly terete ; leaves linear-lance- 912. D. virginiana. 

 olate, closely sessile, rigid ; corolla funnel- 

 form, 4-6 mm. long, whitish, with short lobes, not exceeding the long bristles 

 of the stipules; style undivided; fruit ohovold-tuThinditt, not furrowed, crowned 

 with -4 short calyx-teeth. — Sandy shores and barrens, Ct. to Fla.; and from O. 

 to Kan., and south w. (Mex.. W. I.) 



6. MITCHELLA L. Partridge Berry 



Flowers in pairs, with their ovaries united. Calyx 4-toothed. Corolla-lobes 

 spreading, densely bearded inside, valvate in the bud. Style 1 ; stigmas 4, 

 linear. Fruit a berry-like double drupe, crowned with the calyx-teeth of the two 

 flowers, with 4 small seed-like bony nutlets to each flower. — A smooth and 

 trailing small evergreen herb, with round-ovate and shining petioled leaves, 

 minute stipules, white fragrant flowers often tinged with purple, and scarlet 

 (rarely whitish) edible (but nearly tasteless) berries, which remain over winter. 

 Flowers occasionally 3-6-merous, always dimorphous ; all those of some indi- 

 viduals having exserted stamens and included stigmas ; of others, included 

 stamens and exserted style. (This very pretty plant commemorates Dr. John 

 Mitchell, an early correspondent of Linnaeus, and an excellent botanist, who 

 resided in Virginia.) 



1. M. ripens L. — Dry woods, creeping about the bases of trees, especially 

 Coniferae, throughout our range, and southw. June, July. — Leaves often 

 variegated with whitish lines. Rarely the two flowers completely confluent into 

 one, with a 10-lobed corolla. 



7. CEPHALANTHUS L. Buttonbush 



Calyx-tube inversely pyramidal, the limb 4-toothed. Corolla-teeth imbricated 

 in the bud. Style thread-form, much protruded. Stigma capitate. Fruit small, 

 at length splitting from the base upward into 2-4 closed 1-seeded portions. — 

 Shrubs or small trees, with the white flowers densely aggregated in spherical 

 peduncled heads. (Name composed of /ce^oX??, a head, and 6.vdo%, ajiower.) 



