THE BRAZIL NUT* 
Wy. YOUNG 
(WITH PLATE VIII AND ONE FIGURE) 
The genus Bertholletia, to which is assigned the Brazil nut of 
commerce, was established in 1808 by HumBotpt and BONPLAND, 
who placed in it a single species, B. excelsa. A translation of 
BONPLAND’s description of the fruit of this species is as follows: 
Fruit a spherical, compound nut the size of a child’s head and often 
larger, divided internally into four cells, each of which encloses several nuts; 
covered on its exterior with a husk of a green color, smooth and shining. 
Main nut very solid, rough and marked by branching furrows on its outer 
surface, 6 lines (1 cm.) thick, divided internally into four cells by as many 
membranous dissepiments which become obliterated in part or entirely after 
the maturity of the fruit, but of which there always remain traces. 
The tree is described as 33 m. high, with a trunk 9 dm. in 
diameter. Leaves alternate, oblong, subcoriaceous, 1 dm. broad 
and 6 dm. sea borne on short petioles. Type locality, Rio 
Orinoco. 
On account of the great height of the trees, these botanists 
were unable to obtain the flowers, although it is said that they 
offered in vain an ounce of gold for specimens. On this account, 
they were uncertain as to the position which the genus Berthol- 
letia should occupy. More recent investigations have established 
it next to Lecythis among Lecythidaceae, an arrangement now 
universally accepted. It is worthy of note, also, that BONPLAND 
failed to describe either the operculum or the opercular opening 
of the fruit, although the latter is shown in his drawing as becom- 
ing decidedly narrower at the inner edge. 
For more than half a century after the publication of Bon- 
PLAND’S description of B. excelsa, the genus was accepted as mono- 
typic. Evidence was being gradually accumulated, however, 
which led to the recognition of a second species. Among the 
* Published by permission of the Secretary of Agriculture. 
2 BONPLAND in HUMBOLDT and BonpLanp, Plantes equinoxiales 1: 110, 
3 Spruce, RIcHARD, Notes of a botanist on the Amazon and Andes. Edited by 
A. R, WALLACE. Esa56. 5 
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