4 Campbell.-—Studies on the Araceae. 
as in Anthurium and Lysichiton, or more commonly they are 
unisexual, in which case they may be more or less inter¬ 
mingled, e. g. Spathicarpa , or more frequently with the 
female flowers at the base of the spadix and the male 
occupying the upper portion. Dioecism is rare, but may 
occur in a few forms, e. g. Arisaema triphyllum. 
Dieffenbachia Seguine, Schott. 
Dieffenbachia seguine is one of the commonest of the native 
West Indian Araceae, and a good supply of the early stages 
of the flower was secured, but unfortunately it was too early 
to procure the developing fruits, so that for the present the 
development of the embryo must remain unstudied. 
Owing to the delicate character of the tissues of the young 
flowers they are easily sectioned, and their development can 
be readily followed. The large spadix is enclosed in the 
rolled-up spathe, and is characterized by having the basal 
part occupied by the female flowers, completely adherent to 
the base of the spathe, so that they are developed on one 
side only of the spadix. Each pistillate flower is composed 
of two nearly separate carpels, each containing a single large 
basal ovule. Scattered between the carpels are white, club- 
shaped staminodia. No trace of a perianth is to be seen in 
either male or female flowers. The upper part of the spadix 
projects partly out of the spathe, and is completely covered 
with the crowded male flowers, each of which consists of 
a stalked synangium, recalling in form the peltate sporophylls 
of Equisetum. As is usually the case among Aroids, the 
inflorescence is decidedly proterogynous. 
In sections through the base of a very young spadix, the 
young female flower appears as a hemispherical protuberance 
with a carpel arising on either side (Fig. i). The staminodia 
(st.) are already very evident. The central prominence may 
be considered as the apex of a lateral shoot bearing the 
two carpellary leaves, one of which may perhaps develop 
der Araceae, Nova Acta Acad. Leopold.-Car. xxxix, 1876. Beitr'age zur Kenntniss 
der Araceae, Bot. Jahrbucher fiir Systematik und Pflanzengeographie, v., 1884. 
