KUBIACEAE 1109 



12. Houstonia longifolia Gaertn. Perennial, slender, puberulent or sometimes 

 minutely hispid below. Stems usually tufted, erect or ascending, 2-4 dm. tall, simple or 

 branched, 4-angled and often narrowly winged : leaf -blades linear or linear-oblong, 1-3 cm. 

 long, acute or obtusish, slightly revolute, sessile, ciliolate, dark green above, pale beneath : 

 hypanthium becoming 1.5-2 mm. high : sepals linear-subulate, 2 mm. long at maturity, 

 acute : corolla 8-9 mm. long, pinkish ; tube funnelform, striped with lilac within ; lobes 

 ovate or ovate-lanceolate, acutish, as long as the tube : capsules subglobose, 2.5-3 mm. 

 high. 



In rocky or sandy soil, Maine to Ontario, Manitoba, Georgia and Missouri. Spring to fall. 



13. Houstonia tenuiffclia Nutt. Perennial, glabrous or nearly so. Stems tufted, 

 diffusely branched, slender, often wiry : leaves 1-5 cm. long ; blades varying from ovate to 

 spatulate at the base of the stem to narrowly linear or linear-filiform by the revolute mar- 

 gins above, acute: pedicels filiform, 5-10 mm. long : hypanthium glabrate, becoming 1-1.5 

 mm. high : sepals lanceolate, 1-1.5 mm. long, slightly longer than the hypanthium : corolla 

 pale blue or whitish, 4-5.5 mm. long; lobes lanceolate or oblong-lanceolate: capsules 

 subglobose, about 2 mm. long. 



In poor dry soil, Ohio to Virginia, Georgia and Alabama. Spring and summer. 



14. Houstonia angustifolia Michx. Perennial, glabrous or nearly so. Stems 

 much branched at the base, the branches diffuse, 1-6 dm. long, stoutish : leaves numer- 

 ous ; blades narrowly linear or the lower ones linear-spatulate, 1-4 cm. long, commonly 

 clustered : pedicels 1-4 mm. long : hypanthium turbinate at least during anthesis, becom- 

 ing fully 2 mm. high : sepals lanceolate, about as long as the hypanthium during anthesis : 

 corolla rather salverform, 4-6 mm. long ; lobes oblong or ovate-oblong, pubescent within : 

 capsules oblong except the slightly contracted base, fully 2 mm. thick. 



In dry soil or on prairies, Illinois to Kansas, Florida and Texas. Spring and summer. 



15. Houstonia t6nuis Small. Perennial, glabrous or essentially so. Sterns branched 

 at the base, the branches spreading, 1-2.5 dm. long, slender or wiry : leaves rather numer- 

 ous ; blades filiform or those of the lower leaves narrowly linear-filiform, 1-2 cm. long : 

 pedicels filiform or capillary, 4-11 mm. long: hypanthium turbinate, becoming 2mm. 

 nigh : sepals lanceolate, as long as the hypanthium during anthesis : corolla 3-4 mm. long ; 

 tube very slender ; lobes lanceolate : capsules oblong-turbinate, less than 2 mm. thick. 



In dry soil, Texas. Spring and summer. 



16. Houstonia filifolia (A. Gray) Small. Perennial, glabrous. Sterns diffusely 

 branched at the base, the branches wiry, 0.5-2 dm. long, commonly much branched : leaf- 

 blades narrowly linear or subulate by the revolute margins, 0.5-1.5 cm. long: pedicels 

 2-10 mm. long, capillary : hypanthium turbinate, becoming 1 mm. high : sepals lanceolate, 

 about as long as the hypanthium : corolla white or purplish, 4-5 mm. long ; tube slender, 

 somewhat expanded at the top ; lobes oblong-lanceolate : capsules globose-obovoid, 1-1.5 

 mm. long. [JT. angustifolia var. filifolia A. Gray.] 



In sand, southern peninsular Florida and the Keys. 



17. Houstonia pulviuata Small. Perennial, glabrous, the foliage turning black in 

 drying. Stems branched at the base, the branches 8-12 cm. long, angled, densely tufted, 

 forming cushion-like masses : leaves numerous ; blades linear, 1-1.5 cm. long, acute, revo- 

 lute, more or less curved, sessile : peduncles 1 cm. long or usually shorter : pedicels 1 mm. 

 long or usually shorter, or somewhat longer at maturity, the cymes thus relatively dense : 

 bracts minute, acute: hypanthium broadly turbinate, becoming 1.5 mm. long: sepals 

 triangular-ovate, acute: corolla bluish, 3.5-4 mm. long; tube gradually enlarged; lobes 

 oblong-ovate, about 1.5 mm. long, obtuse, pubescent within : capsules obovoid, fully 2 mm. 

 long, slightly notched. 



In sand, peninsular Florida. Summer. 



18. Houstonia salina Heller. Perennial, glabrous. Stems branched at the base, the 

 branches prostrate, 1-2 dm. long, branching, more or less strongly winged : leaf-blades 

 rather leathery, oblong or linear-oblong, 1-2 cm. long, acutish, revolute, sometimes re- 

 flexed or curved : pedicels 1 mm. long or wanting : hypanthium turbinate during anthesis, 

 becoming 2.5 mm. high : sepals triangular-ovate or ovate-lanceolate, shorter than the hypan- 

 thium : corolla white or pink, 3-4 mm. high, funnelform ; lobes lanceolate or oblong-lan- 

 ceolate, pubescent or glandular within, especially near the margins : capsules oblong-obo- 

 void, 3-3.5 mm. long. 



In sand on the coast, Texas. Spring. 



4. PENTODON Hochst. 



Annual caulescent herbs, with glabrous foliage. Leaves opposite : blades flat, entire ; 

 stipules entire, or 2-3-toothed, adnate to the petioles or leaf-bases. Flowers perfect, in 



