142 Hill. — A Revision of the Geophilous Species of Peperomia. 
examination of Gaudichaud’s specimens from the country round Lima — - 
with which one of Weberbauer’s 1 plants agrees — it is clear that there is at 
least one South American example in which the roots have been carried 
round to the upper surface of the tuber 2 . This species, which I have named 
P. Gaudickandii, has a somewhat different arrangement of its roots in 
old tubers to that seen in the Mexican examples. In the latter case the 
roots arise in a single tuft on one side of the stem-apex 3 , whilst in the 
former (cf. PL XV, Figs. 3 and 4), although the bulb develops at first as in 
P. pedicellctta , yet as it gets older the point of origin of the roots is gradually 
extended round the apex until the leaf rosette is enclosed by a ring of 
roots. These form a mass densely felted together by root hairs, which 
spread over and obscure the small bulb below, so that the leaves and 
inflorescences appear to spring from a dense mass of roots, and the bulb 
may be easily overlooked. Owing to the sharp curving of the central 
cylinder of the hypocotyl in the young tuber, by means of which the 
primary root is carried round to the upper surface 4 , the name campylotropa 
has been given to Kunth’s P. umbilicata from Mexico 5 , which is perhaps 
the best known and most typical species of this group. 
The mode of development of the underground stem in the fourth or 
rhizomatous type is known only in the case of P. macrandra 6 , and 
it is possible that the three or four species, which can be placed in such 
a group, are not really very closely allied. P. mexicana occupies an 
intermediate position between the third and fourth types, since in the 
young plant there is a small warted tuber with a basal root, which appears 
to be carried round slowly to the upper surface ; then by the continued 
growth of the stem-apex a short rhizome is produced, which may produce 
adventitious roots, but retains the old irregular tuber at its base (PL XV, 
Fig* 5 ) 7 * The effect in this case is, on a very small scale, like that produced 
by the rhizome of Cyclamen europaeum 8 . 
The typical rhizome of the group is seen in P. macrandra* , where 
it occurs as a blackish-green, branched organ, creeping probably near the 
surface of the ground. It is some three or more cm. in length, with 
more or less erect branches about 1 cm. long, provided with adventitious 
roots, and marked by large leaf-scars. The mode of development of the 
two other species placed in this group is at present unknown. P. monti- 
cola appears at first to have a campylotropous bulb, which then develops 
1 YVeberbauer, No. 1632 Amancaes, in montibus prope Lima 2-800 m. 
2 Hill in Ann. Bot. xx, footnote (1), p. 396. 3 Ibid., 1 . c., PI. XXX, Fig. 38. 
4 Ibid., 1 . c., PL XXX, Fig. 40. 
5 Kunth in H. B. and K., Nov. Gen., i, p. 59 ; 1 . c., p. 407. 
6 C. DC., in Ann. du Conserv. du Jard. Bot. Geneve, 1878, p. 276. 
7 Hill, 1 . c., p. 41 1, PI. XXX, Figs. 42, 44, 45. 
8 Plildebrand, Die Gattung Cyclamen , p. 22, &c. 
9 Hill, 1 . c., p. 412, PI. XXX, Fig. 46. 
