678 Campbell. — Studies on the Araceae. 
Spathicarpa sagittaefolia. 
The genus Spathicarpa 1 includes four very characteristic 
South American Aroids. The flowers, which are of the 
simplest possible structure, are borne directly upon the upper 
surface of the green leaf-like spathe, no spadix being de- 
veloped. The flowers are arranged, in rows, staminate and 
pistillate flowers being intermingled. The staminate flower 
consists of a peltate synangium borne upon a stalk, and 
closely resembles the peltate sporophyll of Equisetum. The 
pistillate flower (Fig. 35) consists of a single peg-shaped 
carpel, terminating in a small stigma. No perianth is present, 
but between the flowers are numerous small nearly sessile 
staminodia. 
The great simplicity of the flowers suggested that the 
embryo-sac might possibly show correspondingly primitive 
characters, but this was not found to be the case, although 
there were some interesting peculiarities which will be con- 
sidered presently. 
The material used, like that of Aglaonema , was collected 
at Kew, and all belonged to one species, vS. sagittaefolia. 
A brief reference to the structure of the embryo-sac in this 
species has already been published 2 , but a mistake was made 
in the interpretation of certain structures, which has since 
been corrected. 
The peg-shaped carpel of the exceedingly simple flower 
is tipped by a small stigma composed of the usual papillate 
cells. The short style merges gradually into the ovary, which 
is completely filled by the single basal orthotropous ovule 
(Fig. 35). Both integuments are well developed, and, as 
in Aglaonema , the young embryo-sac soon destroys the 
lateral tissue of the nucellus, and thus comes into direct 
contact with the inner integument. 
The earliest stages of the embryo-sac were not seen, but 
from the youngest ones which could be found it is evident 
1 Engler and Prantl, 1. c., p. 145. 
2 Campbell, American Naturalist, Oct. 1902. 
