1108 RUBIACEAE 



as the sepals or slightly longer ; lobes oblong or elliptic, as long as the tube or longer : 

 capsules 3-4 ram. broad. 



On dry hillsides, Missouri to Arkansas and Texas. Spring. 



5. Houstonia subviscosa (C. Wright) A. Gray. Annual, finely glandular-pubes- 

 cent. Stems simple or usually branched at the base, the branches erect or ascending, 5-15 

 cm. long, commonly forking : leaf-blades narrowly linear or some of the basal ones linear- 

 spatulate, 1-3 cm. long, acute : peduncles from the first fork and at the succeeding nodes, 

 shorter than the subtending leaves, spreading, or at maturity reflexed : hypanthinm glan- 

 dular, becoming 2 rnm. high : sepals linear, longer than the hypanthium : corolla white, 

 about 2.5-3.5 mm. long: capsules didymous, 3-3.5 mm. broad. 



On plains or prairies, Texas. Spring and summer. 



6. Houstonia humifusa A. Gray. Annual, depressed, glandular-puberulent. 

 Stems much branched, the branches finally forking and forming dense tufts : leaf-blades 

 linear or linear-spatulate, 0.5-2 cm. long, cuspidate, somewhat fleshy : flowers peduncled : 

 peduncles in all the forks and all the nodes, several mm. long, finally recurved : hypan- 

 thium minutely glandular, flat, barely 1 mm. long at maturity : sepals setaceous-subulate, 

 several times longer than the hypanthium : corolla pale purple or whitish ; tube open- 

 funnelform, about 6 mm. long ; lobes oblong, puberulent within : capsules didymous, 

 plump, 2.5-3 mm. broad. 



On sandy or gravelly hills, Texas. Spring. 



7. Houstonia Cioftiae Britt. & Rusby. Annual, depressed, very sparingly pubes- 

 cent. Stems branched at the base, the branches spreading, 1-2.5 cm. long, simple or fork- 

 ing : leaf-blades spatulate-oblanceolate, 5-10 mm. long, obtuse, revolute, tapering into 

 short petioles : flowers sessile : hypanthium becoming about 1 mm. high, flattish : sepals 

 triangular or triangular-lanceolate, acute : corolla white, about 3 mm. long ; tube funnel- 

 form, thrice as long as the sepals ; lobes oblong-ovate or ovate-lanceolate : capsules didy- 

 mous, 2 mm. broad, pubescent. 



In dry soil, Texas. Spring. 



8. Houstonia rotundifolia Michx. Perennial, hispidulous or glabrate. Stems 

 prostrate, usually creeping, 5-40 cm. long, more or less branched: leaf-blades somewhat 

 fleshy, oval to suborbicular, 5-18 mm. long, obtuse or acutish, ciliate, narrowed into short 

 petioles : pedicels 5-11 mm. long : hypanthium becoming 1-1.5 mm. high : sepals oblong, 

 obtuse : corolla white, about 1 cm. long ; tube slender ; lobes oval to ovate, obtuse or 

 acutish, shorter than the tube : cleistogamous flowers numerous, with well developed but 

 closed corollas : capsules didymous, 3-4 mm. broad. 



In low sandy soil, South Carolina to Florida and Louisiana. Spring to fall. 



9. Houstonia lanceolata (Poir. ) Britton. Perennial, sparingly rough-pubescent. 

 Stems more or less densely tufted, erect or ascending, 1-3 dm. tall, commonly branching 

 above, pubescent in the angles especially near the nodes : leaves thickish ; basal with 

 oblong or spatulate blades and ciliate petioles ; cauline sessile, lanceolate to oblong-lanceo- 

 late, ciliate, acute : pedicels 3-10 mm. long : hypanthium becoming 1.5-2 mm. long : 

 sepals linear, 4-8 mm. long, the tips becoming recurved : corolla lilac or bluish, about 6 

 mm. long ; lobes ovate or nearly so : capsules subglobose, 3-3.5 mm. in diameter. 



In woods, Illinois to Tennessee, Alabama and Arkansas. Spring. 



10. Houstonia purpurea L. Perennial, glabrous or somewhat pubescent. Stems 

 tufted, 0.5-4 dm. tall, simple or sparingly branched : leaf-blades ovate to broadly lanceo- 

 late, or the lower ones oval, oblong or spatulate-ovate, obtuse or acute, ciliate, 1-6 cm. 

 long, the upper one sessile, the lower, or basal ones petioled : pedicels slender, 1-6 mm. 

 long : hypanthium becoming 1.5-2 mm. high : sepals subulate or linear-lanceolate, 2-3 

 mm. long, about as long as the hypanthium at maturity: corolla lilac, light purple or 

 white, 6-7 mm. long ; lobes ovate or oblong-lanceolate : capsules subglobose, obscurely 

 didymous, 2-2.5 mm. in diameter. 



In moist or dry soil, especially on or near the mountains, Maryland to Kentucky, Arkansas, 

 Georgia and Alabama. Spring to fall. 



11. Houstonia ciliolata Torr. Perennial, deep green. Stems usually tufted, erect 

 or ascending, 0.5-2 dm. tall, mostly branched : leaves mainly basal, 1-3 cm. long ; blades 

 oblong or elliptic to spatulate, obtuse or acutish, ciliate, short-petioled or the cauline 

 sessile : pedicels 1-5 mm. long : hypanthium usually sparingly pubescent, becoming 2 mm. 

 high : sepals oblong or oblong-lanceolate, 2-3 mm. long, rather foliaceous : corolla blue, 

 7-9 mm. long ; tube funnelform ; lobes oblong-lanceolate, about twice as long as the tube : 

 capsules subglobose, nearly 3 mm. long, about i free. 



In rocky soil or open woods, Maine to Ontario, Michigan, Pennsylvania and Arkansas. Spring 

 and summer. 



