146 Hill.— A Revision of the Geophilous Species of Peperoniicc . 
Seedlings. 
A few additional facts have come to light about the seedlings of two 
of the geophilous species. A fairly complete series of young plants of 
P. Gaudichaudii was found amongst Weberbauer’s material, and seedlings 
and young plants of P. macrandra — the rhizomatous species — were found 
in the Boissier and De Lessert Herbaria. 
In P. Gaudichaudii the development appears to be exactly similar 
to that described for P. pedicellata , although the youngest stages have 
not been seen. The roots, however, are much more numerous than in 
that species, and are freely branched, so that with their close felt of 
root hairs they form a dense mat over the surface of the tiny bulb (PI. XV, 
Figs. 3 and 4). As the plant gets older the roots are gradually developed 
in a ring-like manner round the top of the tuber, and so encircle the stem- 
apex. The young seedling of P. macrandra has already been described 1 ; 
the older stages now found are of interest, since they show that the rhizome 
is formed directly from the plumule by the slow upward growth of the 
stem-apex, and no curvature of the hypocotyl takes place as in P.pedicel- 
lata , &c. (cf. PI. XV, Fig. 1). The figures of the young plants show the 
radicle at the base of the obovoid tuber with some secondary basal roots, 
and in the older stage two plumular leaves have developed from between 
the cotyledons at the apex of the tuber (Fig. 2). 
Systematic Arrangement. 
Turning now to the systematic arrangement of the various species, 
it is clear, in the first place, that they may be separated into two geo- 
graphical groups, which have no species in common between them, although 
similar biological adaptations may occur in both areas. The following 
is a list of the species from the South American and Mexican regions, 
which, though in some cases imperfectly known, appear to belong to the 
geophilous subsection of the genus. 
South American Species. 
P. macrorhiza 
P. scutellaefolia 
P. umbilicata 
P. Gaudichaudii 
P. peruviana 
P. falsa 
P. parvifolia 
P. verrucidosa 
P. minuta 
P. cyclaminoides 
P. rupiceda 
P. cotyledon 
1 Hill in Ann. Bot. xx, p. 412, PI. XXX, Fig. 48. 
