the yoco which the Indians of the upper Caqueta utilize 
medicinally as a febrifugal tonic. 
The Indians of the Caqueta and Putumayo apparently 
distinguish between different “*kinds’’ of yoco, but I am 
unable to account for the differences. Nearly forty years 
ago, Ratael Zerda Bayon (‘‘Informe del jefe de la ex- 
pedicion cientifica del ano de 1905 a 1906. Lista de las 
muestras de productos del Caquetéa y que podran ser ar- 
ticulos de exportacién.”” (1906) Bogota), writing briefly 
on yoco in his report on a scientific expedition to the Ca- 
queta in 1905-06, stated that the natives distinguished 
four ‘‘kinds’’ of yoco and also reported (translated): 
There is a yoco blanco |“‘ white yoco’’] and a yoco colorado [‘‘red 
yoco’’ ]. 
His specimens have long since been lost, and he does not 
explain the exact nature of the differences between the 
kinds of yoco. 
During my ethnobotanical studies in the Putumayo, 
Lrepeatedly questioned natives concerning the differences 
between yoco blanco and yoco colorado with conflicting 
replies. While it is true that the sap expressed from some 
stems makes a light chocolate-brown mixture when added 
to cold water, that from other stems makes a whitish 
milky mixture. Both taste the same, and both are equally 
effective as a stimulant. he Indians do not prefer one 
to the other. I find that it is impossible to distinguish 
botanically the liana which gives yoco blanco from that 
which yields yoco colorado, but the natives can distinguish 
them immediately by slashing the bark with a machete. 
I have noted that yoco colorado nearly always is a much 
stouter and apparently older plant than yoco blanco, It is 
possible that there is a chemical difference due to age. It 
seems hardly probable that the differences are due to 
seasonal or soil conditions, for yoco blanco and yoco colorado 
grow side by side and can be collected at the same time. 
| SIF | 
