Etymology: From Greek, "hypoleukos," meaning "white 

 beneath," referring to the conspicuously white lower surface of 

 the leaves. 



Distribution: Known only from the upper Rio Negro region 

 of southern Venezuela and the Rio Uaupes of neighboring Brazil. 

 One disjunct population is known from the summit of Cerro 

 Guaiquinima in the State of Bolivar, Venezuela, some 550 km. to 

 the northeast of the nearest populations in the Rio Negro area. 



Ecology: Erythroxylwn hypoleucum grows primarily in savanna- 

 woodland formations on white sand soils known as "Amazonian 

 caatinga" in Brazil and as "bana" in Venezuela; This area is 

 classified according to the Holdrige Life Zone system as "tropical 

 moist forest'' and receives an average of 3400-3600 mm. of rain- 

 fall per year. However, because of the relatively poor white sand 

 soils, the "caatinga" supports only a dwarf forest or savanna 

 vegetation. 



Pufnology: Erythroxylum hypoleucum flowers between April 

 and September; the fruits appear between August and December. 



Common Names and Uses: At San Carlos de Rio Negro, E. 

 hypoleucum is known as "palo de maguari" or "maguari's tree." 

 "Maguari" refers to a malevolent spirit known to local witch 

 doctors, who apparently use the plant for medicinal or magical 

 purposes (H. L. Clark, pers. comm.). The species also is called 

 "cachito" or "palo gallineta" at San Carlos. "Gallineta'' is a 

 Venezuelan name for tinamous who probably eat the fruits of this 

 tree. On the Rio Uaupes in Brazil, E. hypoleucum is called "turi." 



Relationships: Erythroxylum hypoleucum Is closely related 

 to E. lineolatum DC, and probably has been derived from it. 

 Erythroxylum lineolatum is an uncommon species with a scat- 

 tered distribution across northern South America. It is known 

 from the Cauca Valley in northwestern Colombia east to Tri- 

 nidad and grows in a variety of habitats including dry scrublands, 

 bush islands in savannas and moist cloud forest. Erythroxylum 

 hypoleucum may be distinguished from E. lineolatum in having 

 thicker branchlets (2 4 mm. vs. 1.5 2.0 mm. in diameter), more 

 coriaceous leaves, and much thickened, shorter (0.3-0.8 vs. 

 2.0-5.0 mm. long) pedicels. 



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