RUBIACEAE 1117 



Corolla very villous in the throat. 1. s. glabra. 

 Corolla glabrous or slightly pubescent in the throat. 



Leaf-blades more or less scabro-pubescent : capsule didymous : perennial plant. 2. S. tfnuior. 



Leaf-blades smooth and glabrous : capsule subglobose : annual plant. 3. S. Portoricensis. 



1. Speimacoce gldbra Michx. Perennial, glabrous or sparingly pubescent. Stems 

 simple and erect or difiusely branched, the branches spreading or decumbent, 1-6 dm. 

 long, sometimes creeping : leaf-blades oblong, elliptic or oblong-lanceolate, 2-7 cm. long, 

 acute or acuminate at both ends, short-petioled : clusters subglobose, 5-12 mm. in diam- 

 eter : sepals lanceolate, about as long as the hypanthium : corolla white, as long as the 

 sepals or surpassing them ; tube very villous in the throat ; lobes ovate or oblong-ovate : 

 fruit about 3 mm. long. 



On river banks, Ohio to Florida, Arkansas and Texas. Summer. 



2. Spermacoce tenuior (L. ) Lam. Perennial, glabrous or nearly so. Stems 



simple and erect or more or less diffusely branched from the base, the branches 1-3 dm. 



long, rarely creeping ; leaf-blades oblong, elliptic or oblong-lanceolate, 2-5 cm. long, 



acute or acuminate at both ends, narrowed into short margined petioles : sepals subulate 



or lanceolate-subulate, about 1 mm. long, shorter than the hypanthium : corolla white, twice 



or thrice as long as the sepals ; tube funnelfoim ; lobes oblong or ovate-oblong, rounded : 



fruit about 2 mm. long. 



In dry soil or on river banks, Georgia to Florida and Louisiana. Also in the West Indies and 

 tropical America. Summer. 



3. Speimacoce Portoiic^nsis Balbis. Annual, smooth and glabrous. Stems more 

 or less ditiiisely branched from the base, the branches 0.5-3 dm. long, slender or wire-like : 

 leaf-blades oblong to linear-elliptic, 1-2.5 cm. long, acute or acuminate at both ends, in- 

 conspicuously nerved, slender-petioled : clusters few-Howered, mostly less than 5 mm. thick : 

 sepals subulate-lanceolate, 1-1.5 mm. long: corolla white, glabrous within, 1 mm. long; 

 tube campanulate ; lobes oblong-ovate : fruit subglobose, 1-1.5 mm. long. 



In sandy soil, peninsular Florida and the Keys. Also in the West Indies. 



24. GALIUM L.i 



Annual or perennial low herbs, with 4-angled stems. Leaves apparently whorled, 

 the stipules often as large as the leaves. Flowers in our species perfect, small or minute, 

 on axillary peduncles, often cymose. Sepals usually obsolete. Corolla rotate, white, 

 greenisli or purple : lobes 3-4. Stamens as many as the lobes of the corolla and alternate 

 with them : filaments short. Ovary 2-celled, with a solitary ovule in each cavity : styles 2 : 

 stigmas capitate. Fruit composed of two nearly separate globular 1-seeded indehiscent 

 carpels, either glabrous or uncinate-hispid, dry or fleshy, rarely spherical and hollow. 

 Bedstraw. 



Endosperm of the seed deeply lunate or annular in cross-section : leaves various. 

 Fruit uncinale-hispid. 



Leaves and stipules in 7's, not punctate : annual. 1. G. Aparine. 



Leaves and stipules in 4's, pellucid-punctate beneath. 

 Flowers solitary, axillary and terminal : annual. 



Flowers on slender naked stalks, mostly terminal. 2. G. Texanum. 



Flowers on short leafy bracted stalks, mostly axillary. 3. G. virgatum. 



Flowers cymose. terminal : perennial. 



Fruit pedicelled. 4. G. pilomm. 



Fruit sessile or nearly so. 5. G. circaezans. 



Fruit smooth or nearly so. 



Leaves 3-5 cm. long : corolla purplish : endosperm lunate in section. 



Leaf-blades narrowly lanceolate, 1- (rarely 3-) nerved. 6. G. Arkansanum. 



Leaf-blades broadly lanceolate, 3-nerved. 7. G. latifolmm. 



Leaves 2.8 cm. long or shorter. 



Leaf-blades cuspidate, punctate beneath: fruit baccate: endosperm 

 lunate in cross-section. 

 Leaf-blades oblong-oval, 5-2.3 mm. long. 8. G. hhpidulum. 



Leaf-blades linear, 2,5-28 mm. long. 9. G. unifiorum. 



Leaf-blades obtuse, not punctate : fruit dry : endosperm annular in cross- 

 section. 

 Corolla-lobes 3, obtuse : stem scabrous. 10. G. Claytonii. 



Corolla-lobes 4, acute : stem glabrous or nearly so. 11. G. tinctorium. 



Endosperm shallow-lunate, or flat, sometimes nearly circular in cross-section. 

 Fruit glabrous or nearly so. 



Annual : leaves 5-8 mm. long : fruit papillose. 12. G. Parisieme. 



Perennial : leaves 10-20 mm. long : fruit smooth. 13. G. asprdlum. 



Fruit uncinate-hispid. 14. G. trlfioi-um. 



1. Galltim Aparine L. Annual, weak, reclining. Stems 1-15 dm. long, nearly sim- 

 ple, the angles retrorse-scabrous, or prickly : leaves and stipules mostly in 7's, shorter than 



^Contributed by Dr. Karl M. Wiegand. 



