long; cotyledons elliptic, flattened, apically rounded, basally sub- 

 cordate, 8 mm. long, 4.8 mm. wide, 1 mm. thick; radicle 1 .8 mm. 

 long, terete. 



Type: Brazil: State of Rio de Janeiro: City of Rio de 

 Janeiro. Matta do Horto Florcstal. Arvore de 8 12 m. de altura. 

 Matta. 28 Dec 1926 (fr), Pessoal do Horio Florestal s.n., Herha- 

 rio do Servi\o Florestal do Brasil 223 (Holotype, RB 4842; 

 IsoTYPES, RB 4842, 4 sheets; F 1875198, 3 isotypes to be 

 distributed). 



Additional Specimens Examined: BRAZIL: Rio de Ja- 

 neiro: City of Rio de Janeiro, Alto do Boa Vista, Estrada da Vista 

 Chinesa, Centro de Botanica FEEMA-DECAM, cultivated in 

 front of herbarium building, 26 Feb 1983 (st), T. Plowman 12952 

 (F, GUA, RB, 3 duplicates to be distributed). This tree was 

 originally discovered growing in the forest margin at the Parque 

 da Cidade (Parque Federal da Gavea) in the city of Rio de Janeiro 

 by Adelmar Faria Coimbra Filho who collected seeds for propa- 

 gation and distribution at the former Instituto da Conserva^ao da 

 Natureza of the city of Rio de Janeiro. 



Etymology: From Latin "occultus," meaning "hidden, ""con- 

 cealed" or "secret." The name refers to the fact that this species 

 had been overlooked previously by botanists, apparently due to 

 its rarity. 



Distribition: Erythroxylum occultum is known only from 

 the city of Rio de Janeiro. 



Ecology: This species grows in the moist tropical forests that 

 surround the city of Rio de Janeiro. A. F. Coimbra Filho (pers. 

 comm.), who introduced E. occultum into cultivation, asserts 

 that it is an exceedingly rare species which may be in danger of 

 extinction if it is in fact confined to the environs of the city of Rio. 

 However, it may occur elsewhere in the Serra do Mar region and 

 have been overlooked by collectors because of its rather small, 

 inconspicuous flowers and possibly short flowering period. 



Phenology: The only known fertile collection was made in 

 late December. The tree cultivated at the Centro de Botanica in 

 Rio {Plowman 12952) was 6 m. tall in 1983 and at least 15 years 

 old but has never been observed to flower. 



279 



