8 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
Macfad., the “wild soursop” of the West Indies (pl. 7). Very closely allied 
to this are A. sphaerocarpa Splitg., the “bosch-zuurzak,” or wild soursop of Suri- 
nam (pl. 8, B), and A. marcgravii Mart., based upon the Brazilian “aratica 
ponhé” described by Marcgrave in 1648 (pl. 10). These species will be dis- 
cussed later, together with the question as to the identity of Marcgrave’s “aratict 
apé,” a species closely resembling A. muricata. Other species belonging to this 
section are A. coriacea Mart. and the dwarf A. pygmaea Warming (fig. 7). 
The section Euannona differs from the section Guanabani, hitherto accepted 
by botanists, chiefly in the elimination of Annona glabra L., in which the ovaries 
are fused together in the flower, on account of which the writer has made it 
the type of a section Phelloxylon, described below. ‘The African Annona 
Fic. 7.—Annona pygmaca. 8, 8, Surface of soil; A, calyx seen from above; B, outer petal; 
Cc, inner petal; D, stamens; ZH, hairy ovary tipped with fleshy style; F, flower deprived 
of its petals and part of its stamens. Reproduced from Warming. 
senegalensis Pers. and A. stenophylla Engl. & Diels, are also excluded on account 
of their narrow, triquetrous inner petals. 
Section 2. PSAMMOGENIA sect. nov. 
Type species, Annona salzmanni A. DC. (fig. 8; pl. 11). 
The flowers of this section bear a close resemblance to those of Euannona 
and, as in that section, they are sometimes geminate. The leaves, however, 
in their coriaceous texture and their peculiar nerves, which appear to be 
impressed on both surfaces instead of being more or less prominent beneath, 
differ from the leaves of Euannona and from all other sections of the genus. 
