Specei nomen professorem rerum herbarum demortu- 
um Oakes Ames Universitatis Harvardianae, quis studia 
mea plantarum somnificarum inter indigenas americanos 
excitavit, honorat. 
Methysticodendron is here described as a genus of the 
Solanaceae with some hesitation, for the concept shows 
several characters which are not easily accommodated in 
that family. 
In habit, Methysticodendron A mesianum is a small tree 
quite suggestive of some of the larger tree-species of 
Datura, i.e., D. arborea L., D. suaveolens HBK. and 
D. Rosei Safford. Like these members of the Brugman- 
sia section of Datura, the new concept is characterized 
by large, pendulous flowers. The intoxication which a 
decoction of the leaves of Methysticodendron A mesianum 
induces bespeaks the presence of similar alkaloids: hyos- 
cyamine and scopolamine. There are also strong similari- 
ties in the branching, as well as in the structure of the 
calyx and stamens. 
The pollen grains of the type plant of Methysticoden- 
dron have been studied by Dr. Thomas van der Hamen, 
palynologist to the Servicio Geolégico Nacional of Co- 
lombia and by Professor Elso S. Barghoorn of the Botan- 
ical Museum of Harvard University. Dr. Barghoorn’s 
description of the grains follows: 
Pollen grains spherical, chiefly inaperturate, occasionally tricolpo- 
rate or triporate with very weakly developed short furrows. Size rang- 
ing from 45p/ to 63/4, averaging about 53» (after acetylation), Sculp- 
turing of the exine striate, and of the ‘‘finger print’’ pattern of stri- 
ation. Striae converging at the poles and commonly anastomising be- 
tween the poles. Polar areas reticulate-foveolate. A feeble punctate 
or reticulate texture may be detected between the striae or along their 
sides. Equatorial costae conspicuous. 
In basic morphology the grains are a modified bipolar, tricolpate 
type, in which both pores and furrows have been greatly reduced. 
