746 RUBIACEAE (MADDER FAMILY) 



10. P. aristata Michx. Similar ; loosely hairy and green, or becoming gla. 

 brous ; tlie narrowly linear bracts 2-6 times as long as the flowers. (P. patagon- 

 ica, var. Gray.) — Dry plains and prairies, 111. to La., and westw. ; naturalized 

 in sterile soil eastw. to the Atlantic. 



§ 2. Flowers s2ibdioecious or polygamo-cleistogamous ; the corolla in the fertile 

 {or mainly fertile) plant dosed over the maturing capsule and forming a 

 kind of beak, and anthers not exserted; sterile flowers with spreading corolla 

 and long-exserted filaments ; seeds mostly flat; small annuals or biennials. 

 n. P. virginica L. Hairy or hoary-pubescent, 0.5-4 dm. high; leaves ob- 

 long, varying to obovate and spatulate-lanceolate, 3-5-nerved. slightly or coarsely 

 and sparingly toothed ; spikes mostly dense, 1-9 cm. long ; fruiting calyx 1.5-2.5 

 mm. long ^ mature corolla slender-cylindric ; seeds usually 2, brown or yellow- 

 ish, 0.8-1.5 mm. Zon(/. — Sandy grounds, chiefly near the coast, R. I. to Fla. and 

 Tex.; inland in Miss, basin to s. Mich., 111., Mo., and Kan.; also on the Pacific 

 slope. (Mex.) 



12. P. RHODosPERMA Dcnc. Similar to the preceding; fruiting calyx 3-4 

 mm. long; mature corolla slender-conical; seeds reddish, 2.5-3 nvm. long. — 

 Dry prairies and open woods. La. to Ariz, and n. Mex.; adventive in Mo. 



13. P. elongata Pursh. Minutely pubescent, 3-16 cm. high ; leaves linear 

 to filiform, entire; capsule short-ovoid, 4-seeded, little exceeding the calyx and 

 bract. (P. pusilla Nutt.) — Sandy soil, s. Mass. to Ga.; and from 111. to Assina., 

 La., and westw. Apr.-Aug. 



14. P. heterophylla Nutt. Leaves rather fleshy, acute, entire, or some of 

 them 2-1-lobed or toothed below ; capsule slender-conoidal, 10-28-seeded, nearly 

 twice the length of the calyx and bract. — Low sandy ground, N. J. to Fla., 

 Tex., and Ark. Apr. -June. 



RUBIACEAE (Madder Family) 



Woody or herbaceous plants, with opposite entire leaves connected by inter- 

 posed stipules, or in luhorls without apparent stipules, the calyx adherent to the 

 2-4-celled ovary, the stamens as many as the lobes of the regular corolla (4-5), 

 and inserted on its tube. Flowers perfect, but often dimorphous (as in Mitchella 

 and Houstonia') . Fruit various. Seeds anatropous or amphitropous. Embryo 

 commonly rather large, in copious hard albumen. — A very large family, the 

 greater part, and all its most important plants (such as the Coffee and Peruvian- 

 bark trees), tropical. 



iV. B. — The fig-ures in this family are on a scale of |. 



Subfamily I. COFFEOtDEAE. Ovules solitary in the cells 



* Herbs. 

 +- Leaves in whorls. 



1. Shei-ardia. Corolla funnal-form. Calyx-lobes lanceolate. Flowers subsessile, involucrate. 



2. Asperula. Corolla tubular-campanulate below. Calyx-lobes obsolete. Fruit as in Galium. 



3. Galium. Corolla wheel-shaped, 4 (or rarely 3)-parted. Calyx-teeth obsolete. Fruit twin, 



separating into 2 indehiscent l-seeded carpels. 



+- +- Leaves opposite. 

 ++ Flowers axillary, separate ; fruit dry when ripe. 



4. Spermacoce. Corolla funnel-form or salver-form ; lobes 4. Fruit separating when ripe int* 



2 cai'pels, one or both of them opening. 



5. Diodia. Fruit separating into 2 or 3 closed and indehiscent carpels ; otherwise as no. 4. 



++ ++ Flowers twin ; their ovaries united into 1 ; fruit a 2-eyed berry. 



6. Mitchella. Corolla funnel-form ; its lobes 4. A creeping herb. 



* * Shrubs or trees. 



7. Cephalantlius, Corolla tubular ; lobes 4. Fruit inversely pyramidal, 2-i-Beeded. 



