SYNOPSIS OF THE SPECIES OF DIOSCOREA. 



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3. Dioscorea paiiiculata Michx. Rhizomes long and slender, simple 

 or rarely forked, less than 1 cm. in diameter, with a few short lateral 

 branches of less diameter. Stem 1 to 4 m. long, flexucns, glabrous. 

 Leaves all alternate, or two or three of the lowest subapproximate, 

 pubescent or puberulous beneath. Petioles glabrous at the insertion 

 of the blade, or, if pubescent, less densely so than the blades. Stami- 

 nate inflorescences solitary, borne only in the leaf axils of the upper 

 half of the stem, the three or four lowest less branched than those 

 higher up. Pistillate inflorescences densely many fruited. Capsules 

 2 cm. long or less. 



Fig. 3. — Map of the eastern portion of the United States, showing the distribution of 

 Dioscorea paniculata (liy dots) and its variety glabrifolia (l\v crosses). 



Var. glabrifolia Bartlett.*^ Leaves altogether glabrous. This va- 

 riety replaces the typical form of the species in the southwestern part 

 of the range. Various northeastern specimens are indistinguishable 

 from the southwestern plant, but may be genetically distinct from it. 

 In the distribution map (fig. 3) the range of the variety is shown by 

 crosses. 



"• Dioscorea paniculata glabrifolia var. nov. Foliis glabris exceptis, forniae 

 specie! typicae omnino siniilis. A. 8. Hitchcock, 830 (pro parte) "Woods, 

 Cherokee Co., Kansas, 1896." 

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