PITTTER PLANTS FROM COLOMBIA AND CENTRAL AMERICA. 115 



All Central American specimens contained in the U. S. National Herbarium are here 

 included under the name of 0. cordi/olium (Vent.) Schlechter, but there are certainly 

 striking differences in their minor details, and were it not for a decided reluctance 



a b c 



Fig. 20.— Translator^ of Oxypetalum cordifolium. a, From no. 10862, Institute ffs.-geog. Costa KIca; b, 

 from no. 12388, herb, cit.; c, no. 4000, Donnell Smith Herbarium, a, b, c, Scale 32. 



to founding new species on scanty material and the impossibility of comparing 

 these at present with the types existing in other collections, one would feel 

 inclined to separate them. Thus there 

 is no Bmall divergence in the form of 

 the leaves, these being typically heart- 

 shaped and large in nos. 577308 (Costa 

 Rica) and 207252 (Guatemala), and 

 rather cordiform-lanceolate and small 

 in nos. 243231 (Guatemala) and 577583 

 (Costa Rica). While the calyx and 

 the corolla show little variation, the 

 leaflets of the corona differ widely in 

 form and size from one specimen to the 

 other, as shown in fig. 19, the only con- 

 stant feature being the inside finger- 

 like appendage with bituberculate base. 

 There is, furthermore, a general and 

 seemingly constant difference in the 

 dimensions of all floral organs, the San 

 Pedro plant showing maxima, the Guate- 

 malan one minima, while the Atenas 

 plant comes between them. 



Fig. 21.— Flower parts of Oxypetalum huilcnse. a, Fo- 

 liole of corona; 6, stamen; c, translatorium. a, b, 

 Scale 9; c, scale 32. 



Oxypetalum huilense Pittier, ap. nov. Figure 21. 



A voluble, milky vine, with subligneous, slender, sparsely ramified stems, smooth 

 and finely striate on the older part, pubescent in the younger ones. 



Leaves opposite, petiolate, rather small. Petioles slender, 1.5 to 2 cm. long, pubes- 

 cent Leaf blades 4 to 6 cm. long, 1.8 to 2.5 cm. broad, lanceolate or narrowly ovate- 



