New Species of Sotjth American Plants 7 



Dioscorea Herbert- Smithii. 



Inflorescence and veins of lower surfaces of young leaves 

 minutely puberulent. Branchlets slender, terete, the inter- 

 nodes about 7 cm. long. Petioles of full-grown leaves 5 cm. 

 long, narrowly channelled above and sulcata on the sides, the 

 blades 7 to 12 cm. long, 4 to 10 cm. broad, regularly ovate and 

 cordate, the basal lobes regularly rounded, broader than the 

 sinus, which is also rounded, the summit abruptly short-acumin- 

 ate and very acute; 5-ribbed, the 2 outer pair basal only, the 

 next pair running almost to the summit where they approach 

 the midrib, the venation dark, broad and flat, crooked. Leaf 

 very thin. The inflorescence leaves of the staminate plant are 

 small and the base is very shallowly cordate, or sub-truncate. 

 Staminate inflorescence sessile, branching at the base into about 

 5 to 7 racemes which are 5 to 7 cm. long, slender, rather densely 

 flowered, and bearing many small, ovate, scarious bracts at 

 the base. Staminate flowers sessile or sub-sessile, 3 mm. broad, 

 the base 3-bracteolate, the bracts scarious, broadly ovate, 

 obtuse, half as long as the perigone, which is divided half way, 

 its lobes ovate, obtusish. Stamens 6, the broad filaments con- 

 nate in a short saucer-shaped tube, the anther-cells contiguous. 

 Pistillate flowers similarly bracteolate, the ovary oblong, 3 

 mm. long, the lobes of the perigone erect, about half as long as 

 the ovary, broadly ovate, obtuse. Staminodia none. Style 

 branches entire. 



"Twining to 15 feet in a thicket, border of woods, 6 miles 

 from Mamatoca, 500 feet, April 10. Flowering earlier than 

 2302." (Herbert Smith, Colombia, No. 2301.) 



Dioscorea hastatissima. 



(Staminate Plant.) 

 Inflorescence puberulent. Branchlets elongated and very- 

 slender, strongly sulcate, the ridges obtuse, the internodes 

 about I dm. long. Petioles 4 to 6 cm. long, sulcate like the 

 branchlets. Blades 7 to 12 cm. long and somewhat broader, 

 3-lobed nearly to the base, the lateral lobes divaricate, one or 

 both sometimes wanting, the middle lobe 6 to 10 cm. long, 2.5 

 to 6 cm. broad, regularly ovate, the base little contracted, the 

 summit acuminate and acute, 3-ribbed, the lateral lobes in- 

 equilaterally -lanceolate, 2-ribbed or with 2 additional lighter 

 oaes, acuminate and acute, the coarsely reticulate venation not 

 conspicuous. Axillary inflorescence very loosely paniculate, 

 the racemes 6 to 12 cm. long, very slender, loosely flowered, 

 subtended by thin, weak, lanceolate attenuate bracts about 

 3 mm. long. Pedicels very slender, 2 to 3 mm. long, their bracts 

 about half as long. Flowers 3 mm. broad, lobed nearly to the 

 base, the lobes oblong, obtusish, with a slender greenish middle 



