AUG. 1899. STUDIES IN THE HERBARIUM. I. ULINE. 415 



column. Members of the section Monadelpha Uline, of the 

 genus Dioscorea, occurring in southern Brazil, Paraguay, Argen- 

 tina and Bolivia, are variously inclined to coalescent filaments, 

 but their seeds are of the Helmia type, /. e. , winged only in one 

 direction, instead of all around. Although the coalescence of 

 the Monadelpha section is characteristically different from that 

 of our plant, it does not follow that the character of filament 

 coalescence may in the above-described plant be interpreted as a 

 generic character. For throughout the genus Dioscorea, species 

 showing closest relationship in the character of the female flow- 

 ers were found often to differ widely in their staminate flowers. 

 Hence it is not improbable that a second species displaying 12 

 ovules in the capsule, should such ever be found, might display 

 an entirely different set of characters in its male form from that 

 below described. Furthermore, there are certain characters in 

 our plant, which, while not found in any known Dioscorea species, 

 nevertheless do not differ more widely from known Dioscoreas* 

 than numerous sections of the genus Dioscorea differ among one 

 another. Such characters are : the presence of staminodia car- 

 ried up to the apex of the column with the anthers (members of 

 the section Monadelpha having no staminodia) ; the very long 

 rachides of the pistillate flowers (often over 2 feet) ; and the very 

 minute embryo with the obscure plumule at the base. (This 

 plumular structure required hours of manipulation to discover, 

 while in other members of the family it is always easily seen 

 under | to \ objective comp. micr.). In view of these con- 

 ditions the writer is therefore compelled to present the genus 

 tentatively, offering the 4-ovuled feature as the only positive 

 generic character. To what extent certain of the above-men- 

 tioned characters may be ultimately found to be generic or spe- 

 cific, must remain an open question until more is known about 

 generic relations in the group. 



Higinbothamia synandra Uline, n. sp. (Plate XXII.) 



Planta glabra, scandens, caulibus crassis, sinistrorsum tortis ; 

 foliis membranaceis, y-nerviis, orbiculari-cordatis, subtus ad 

 basin glandulis sparsis adspcrsis ; racemis solitariis, gracilli- 

 mis, folia superantibus ; floribus solitariis brevipedicellatis, 

 ad racemos laxiter dispositis ; antheris tribus sordido-purpu- 

 riis, ad apicin columnar androecialis gracilis extrorsum inser- 

 tis, et cum tribus rudimentis similiter sitis perbrevibus sim- 

 plicibus obtusis crassiusculis albis obsolete papillosis alter- 



