ide prominenti et faciebus satis amplis. In terris saxosis, 
semi-xerophyticis, in plantarum societate quae in lingua 
brasiliense ‘‘caatinga’’ nominatur, in locis usque ad circa 
mille pedes altitudine crescit. Nomen vulgare ‘‘serin- 
gueira’’ vel ‘‘seringueira da serra’’ est. 
CoLLECTIONES EXAMINATAE: 
Brazit: Estado do Amazonas, prope Panuré [Ipanoré] ad Rio 
Uaupés, Oct. 1852-Jan. 1853, Richard Spruce 2527 (Typr cotiection). 
Brazit: Estado do Amazonas, Jauareté, Uaupés, Rio Negro. ‘‘Ar- 
vore de 9 m., 25 cm. [diam.]; folhas coriaceas, um tanto pendentes. 
“*Seringueira.’? Oct. 22, 1945, Ricardo de Lemos Frées 21258. 
Brazit: Estado do Amazonas, Iraruca, Rio Igana. ‘*Arvore, 7m., 
15 cm. [diam. |. Casca fina, latex branco, abundante, coagulavel. Fol- 
has pendentes, coriaceas.’’ Nov. 16, 1945, Ricardo de Lemos Frées 
21394, 
Brazit: Estado do Amazonas, adjacencias da serra de Tunuhy, 
estando-se até a $08 metros dealtitude. *“Rica em latex branco, coagu- 
lavel.’’ Nov. 14, 1945, Ricardo de Lemos Frées 21401, 
Brazit: Estado do Amazonas, Serra Tunuhy, [Rio] Icana, Rio 
Negro. May 5, 1947, Ricardo de Lemos Frées 22303. 
Brazit: Estado do Pard, Belém do Parad. “*Seedling cultivated in 
Instituto Agrondédmico do Norte, collected by J.T. Baldwin, Jr., at 
Montepelago, Rio Uaupés, Estado do Amazonas, March 1944. Ster- 
ile.’’ August, 1947, Richard Evans Schultes 8663. 
The distribution of Hevea rigidifolia 
The small number of stations now known for Hevea 
rigidifola indicate that it is, with all probability, a highly 
restricted endemic, for the rather extensive collections 
of Hevea which have been made in other regions® in the 
Amazon Valley have never yielded this species. 
Hevea rigidifola appears to be centered near the con- 
fluence of the Rio Negro with the Rio Vaupés, or, more 
precisely, in the triangular sector formed by the lower 
course of the Rio Vaupés, the Rio Negro above its con- 
® Hevea rigidjfolia is erroneously attributed ‘‘am mittleren Orinoko’’ 
in Planzenr. IV. 147 (Heft 42) (1910) 124, 
[ 106 | 
