122 MEMOIRS FEOM THE DEPARTMENT OF BOTANY OF COLUMBIA UNIVERSITY 



Plants generally less than 3 dm. high. 



Hypanthium cupulate ; petals spatulate-oblong. 11. S. cmieata. 



Hypanthium saucer-shaped; petals broadly obovate. 12. H. platypetala. 



§3. CAPITATAE. 



In general habit resembling the preceding group, but the inflorescence more con- 

 tracted, fastigiately corymbose-cymose or subcapitate. Hypanthium deeply cup-shaped ; 

 bractlets linear. Filaments of the outer stamens much broader than those of the inner 

 ones, broadly triangular. Pistils numerous. Petals, except in Nos. 13 and 19, obcordate, 

 unguiculate, white, or often tinged with rose. 



Leaflets merely toothed (except sometimes iu the first species). 



Plants less than 2 dm. high ; cyme fastigate-corymbose ; pubescence dense. 



Pubescence densely silky-canescent. 13. H. Render sonii. 



Pubescence densely glandular puberulent. 14. H. parviflora. 



Plants generally over 2 dm. high. 



Pubescence of both leaves and stem more or less villous. 15. H. pseudocapUata. 



Pubescence rather scant, on the leaves scarcely any, on the upper part of the stem glandular. 



Leaflets obovate or oval, 2-3 cm. long ; bracts generally exceeding the inflorescence. 



16. H. capitata. 

 Leaflets obovate or cuneate, . 75-2 cm . long ; bracts shorter than the inflorescence. 



17. S. fusea. 

 Leaflets divided more than half way to the mid vein into linear or linear-oblong segments. 



Stem glandular above; petals cuneate, emarginate. 18. H. tenella. 



Stem hirsute-villous, not glandular ; petals oblong. 19. S. tenuiloba. 



§4. TRIDENTATAE. 



Stems slender and ascending ; leaves pinnate with 2-4 pairs of cuneate leaflets, which 

 are 2-3- (seldom 5-) toothed at the apex. Hypanthium cupulate or campanulate. 

 Petals oblanceolate or spatulate, unguiculate, white or yellowish. Stamens JO; fila- 

 ments often linear-lanceolate. Pistils few, 5-15. 



The group approaches Ivesia in several characters, viz., the narroAV filaments, few 

 pistils and the form of the petals. It is, however very nearly related to the following 

 one, with which H. congc^fa connects it ; in tliat species the lower stipules are occasion- 

 ally pinnately dissected. 



Petals white, oblanceolate ; fllaments linear-lanceolate ; cyme rather fastigiate. 20. H. tridentata. 

 Petals yellowish, at least in dry specimens. 



Cyme subcapitate ; outer filaments triangular to lanceolate. 2I. ff. flavescens. 



Cj-me few-flowered and open; filaments all linear-lanceolate. 22. H. congesta. 



