AUG. 1899. STUDIES IN THE HERBARIUM. I. ULINE. 417 



The general appearance of this plant, the disposition of its 

 minute sessile flowers on the rachis, and especially the presence 

 of minute spatulate rudimentary stamens, alternating with the 

 short extrorse fertile stamens, all point unmistakably to a real 

 relationship to D. polygonoides H. & B.; but it is at once distin- 

 guished in general by its delicate slender habit. It probably 

 does not attain a length of more than 4 or 5 feet, for it was found 

 growing on Capraria biflora, not spreading from plant to plant, 

 but attaining its growth largely on a single individual. The 

 staminate plant is readily distinguished from D. polygonoides by 

 solitary flowers. The latter species always has its staminate 

 flowers more or less densely bunched at irregular distances on 

 the rachis. It will be seen also that the anthers are not discrete 

 as in D. polygonoides, but irregularly introrse. The oblong 

 perianth-lobe, in contrast to the usually orbicular form present 

 in D. polygonoides, also serves to confirm the distinctness of the 

 species. Though no mature capsules have been seen, yet the 

 short few-flowered rachides of the pistillate specimen, and its 

 short ovaries, some of them already as broad as long, suggest a 

 very different plant from D. polygonoides, with its long rigid 

 rachis and large capsules. 



Dioscorea Matagalpensis Uline in Engl. Jahrb. xxii, 3: 432. 



Forma staminata nova : Facies ut in planta supra citata, in 

 sicconigrescens, floribusin glomerulos 3 4floros inaequidistantes 

 dispositis ; perianthii lobis ovato-oblongis, obtusis, aequalibus ; 

 staminibus fertilibus tribus cum tribus sterilibus spatulatis inae- 

 qualiter bidentatis obscuro papillatis alternantibus omnibus in 

 tubo supra basin insertis; antheris parvis, surso-extrorsis, loculis 

 vix discretis; rudimento stylino nullo. 



Caulis gracillimus, sinistrorsum volubilis. Folia usque ad 3 cm. 

 longa lataque. Spica 10 cm. longae, simplices vel ramosiusculae. 

 Perianthium 1.5 mm. latum, segmentis basi nunquam auriculatis. 

 Stamina fertilia brevia, segmentis perianthii fere dimidio breviora, 

 sterilia paullo superantia. 



Yucatan, GAUMER, 1391, staminate form. Specimen in Field 

 Col. Mus. Herb. cat. no. 57320. 



From the entire appearance of the plant and, as was to be 

 expected, the presence of staminodia alternating with the fertile 

 stamens, there can be no doubt that this is the hitherto unknown 

 male form of D. Matagalpensis. Its discovery is especially for- 

 tunate, for it is now possible to determine the affinities of D. 



