112 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



II. B. K., and 0. Undenianum Turcz., the first two names being 

 generally considered as synonyms. In addition to these, one species 

 from Colombia is here described for the first time and probably two 

 more have been confounded under one of the former names. All 

 these species belong to the subgenus Euoxypetalum (Decaisne) 

 Malme, characterized by broad, almost horizontal caudicles and by 

 each caudicle being provided with a lateral, more or less excurved 

 hornlet. 



The first difficulty in classifying these species is as to their place 

 in the five sections established by Malme. The fundamental charac- 

 ters made use of here are the dimensions and form of the retinaculum, 

 the form and coherence of the crown leaflets, and the presence or 

 absence of a horn-like appendage on the inner face of the latter. 



So far as the first two groups of these characters are concerned, we 

 are very well satisfied that the enumerated species all belong to the 

 section Odontostemma Malme. We remain in doubt, however, when 

 it comes to the last, which may be the fundamental, distinction on 

 which the section is based, viz, the presence on the. inner face of each 

 crown leaflet of a more or less free, horn-like appendage. 



This appendage is clearly indicated in Ventenat's description of his 

 Gothofreda cordifolia a and in figure 6 of the accompanying plate. 

 No appendage is mentioned in Kunth's description of the corona 

 of Oxypetalum riparium H. B. K., 6 whence most of the later authors 

 have concluded to its absence. Turczaninow is silent as to this 

 detail in describing his O. Undenianum. All the Costa Kican and 

 Guatemalan specimens and my own from Colombia, are appendicu- 

 late, while the Cuban ones are not so. 



With reference then to the presence or absence of the appendage 

 on the leaflets of the corona, 0. cordifolium, together with the plant 

 collected by me in the. Paez Valley and with the Central American 

 species, would belong to section 3, Odontostemma Malme, while 

 0. riparium and the Cuban specimens should be placed in section 4, 

 lihipidostemma Malme. The place of 0. Undenianum remains 

 doubtful. 



Notwithstanding the opinion of several authors, beginning with 

 Roemer and Schultes/ as to the identity of Oxypetalum riparium and 

 0. cordifolium, I believe that they are distinct species. First of all, 

 as above stated, they belong to different sections by one of the essen- 

 tial characters upon which the subdivisions of the genus are founded. 



^ a Ecailles . . . munies vera leur base interne de deux glandes entre lesquelles 

 s'eleve un corps cylindrique et corn-be" en dedans. Ventenat, Choix PI Cela 60 (au 

 re vers). 1803. 



b Corona pentaphylla . . . ; foliolis cum laciniis corollae alternantibus, cuneatis, 

 apice dilatatis, obliquis et emarginatis aut bilobis, crenulatis, carnosis, margine 



tenuioribus.basiadutrumquelatusgibbosisjgibbisrotundatis.— H B K Nov Gen 

 &Sp. 3: 198. 1818. 



c Syst. Veg. 6: 92. 1820. 



