114 WaTsON: THE GENUS HELIOCARPUS 
is very variable. The fruit and flowers are practically identical. 
Hochreutiner also points out that H. Nelsoni Rose is the same 
as a plant that was originally incorrectly placed in the genus 
Grewia under the specific name of ferebinthinaceus. To quote 
Hochreutiner, ‘‘nous avons 4 l’'Herb. Delessert un original du 
jardin de Montpellier, déterminé par de Candolle et en outre, 
le no. 1064 de Berlandier, cité par Rose sur l’apui de son H. 
Nelsoni, et ces deux plantes sont identiques.” Hochreutiner’s 
conclusion seems tenable. 
I have not seen the type of H. stipulatus, Poeppig 3 102, nor 
any plant of the genus that answers to his description. Botteri 
1110, Gray Herbarium, does, indeed, fulfil the requirements of 
the description, but, unfortunately, does not belong to the 
genus. The inflorescence is, as Hochreutiner says in his de- 
scription, “divaricata, ramosa plus minus corymbiformis,” 
which is not characteristic of this genus, and the structure of the 
flower is less so. 
Concerning the characters of the genus Heliocarpus, it is to 
be noted that the knowledge acquired by the examination of a 
large amount of material renders inadequate the diagnoses of 
Engler and Prantl and of Bentham and Hooker. In T riumfetta, 
a closely allied genus, the apex of the receptacle, above the sepals 
and petals, is crowned by a saucer-shaped structure with ciliate 
rim in which repose the ovary and stamens. This structure is 
not found in any of the undisputed species of Heliocarpus but is 
present in all the species of Triumfetta that I have examined. 
Also, in Triumfetia, the sepals are usually, if not always, long- 
appendaged, while in Helocarpus, the appendages, if any, are 
short. In Triumfetta, the style is usually long and more or less 
capitate, while in Heliocarpus it is invariably bifid with spreading 
lobes. Seemann 96 and Pittier 5017, both from Panama; Lan- 
glassé 708, from Guerrero, type of H. tigrinus; and Botteri III0, 
from Vera Cruz, all have these characters of 7 riumfetta and 
are accordingly considered as not to belonging to the genus | 
eliocarpus. , 
An effort has been made to render the appended key available 
for herbarium use. Its artificiality is made necessary by the 
fact that many specimens will lack either fruits or flowers. I 
have followed Rose in the division of the group into those with 
stipitate and those with sessile fruits, but this character must be 
