1963] 



BOTANY OF THE GUAYANA HIGHLANDS PART V 



259 



alatis, alis brunneis 2.7 mm latis corpusculo ferrugineo 30-35 mm longo 18 mm 

 lato (alto), testa dense conspicue papillata. 



Distribution. Known only from Mount Ayanganna, British Guiana. 



BRITISH GUIANA. Frequent in woodland between Chinowieng and Chi-Chi 

 landing, Mount Ayanganna, Pakaraima Mountains; alt. 1000 m; tree 15-20 m 

 tall with flaking bark ; leaves pale beneath ; 10 Feb 1955, B. Maguire, W. M. C. 

 Bagshaw, and C. K. Maguire 40666 (holotype NY, isotype VEN). 



This species marks the most easterly limit of the genus Platycarpum, and is 

 the only one of them thus far known from British Guiana. In its large capsules 

 and seeds it finds its closest ally in the geographically near P. rugosum Steyerm., 

 but is at once distinguished from that species by the absence of glands on the 

 petiole, being the only instance of such thus far known in the genus, otherwise 

 well-marked by the occurrence of such petiolar glands. The leaves are more 

 prominently pubescent on both surfaces than in P. rugosum, and the lateral pairs 

 of nerves of the leaf-blades are more numerous than in P. rugosum. The two 

 types of pubescence found on the lower surface of the leaf-blades in P. eglandu- 

 losum, expressed by a vestiture of soft dense hairs covering a minute tomentum 

 in the reticulum of the veinlets, are known also in P. orinocense, but the latter 

 species has smaller capsules and seeds, and has paired instead of ternate leaves. 



Schradera Vahl, Eclog. Am. 1 : 35. /. 5. 1796. 



Fuchsia Sw. Prodr. Veg. Ind. Oce. 62. 1788, not Fuchsia L. 1753. 



Urceolaria Willd. in Cothenius, Dispos. Veg. 10. 1790, hyponym ; J. F. Gmel. Syst. Nat. 

 - 2: 390. 1791. 

 Uncariopsis Karst. Linnaea 30: 152. 1859. 



This genus is one of the nomina generica conservanda (See Appendix III. 

 p. 312, International Code of Botanical Nomenclature. 1961. Utrecht, Nether- 

 lands; also see Taxon 9(4) : 118. Apr-May. 1960), and is maintained as such in 

 the present treatment. 



At the time Standley published Schradera surinamensis in 1948 (Bull. Torrey 

 Club 75: 569), he noted that "Until recently few specimens of Schradera have 

 been collected in South America, but those now coming to hand in greater 

 numbers indicate that the genus is represented there by a rather large number 

 of only slightly different but apparently well-marked species." 



A study of recent collections from South America since 1948, especially from 

 the Guayana Highlands and from the Pacific Coast of Colombia, reveals an even 

 greater number of undescribed taxa than was originally suspected. The first of 

 these, S. nilssonii Steyermark, was published in 1962 (Bol. Soc. Ven. Cien. Nat. 

 23(101) : 83), and the remainder are presented in the present paper. Continued 

 exploration of the South American countries will doubtless augment to an even 

 greater extent the total number of distinct taxa. 



The results of the present study are based upon material of the genus existing 

 in the herbaria of the Chicago Natural History Museum, The New York Botanical 

 Garden, and the United States National Museum. 



Key to the Species of Schradera 



1. Flowers solitary, each one subtended by an individual involucre; Peru. S. siibandina. 



1. Flowers capitate, three or more together subtended by a common involucre. 

 2. Involucre 25-35 mm high, nearly concealing the flowers at anthesis. 



3. Involucre 25 mm high; calyx and hypanthium 10-13 mm long; corolla about 



15-20 mm long, the tube somewhat longer than the lobes; Colombia. S. lehmannii. 



