The Morphology and Seedling Structure of the Geo- 
philous Species of Peperomia, together with some 
Views on the Origin of Monocotyledons '. 
BY 
ARTHUR W. HILL, M.A. 
Fellow of Kings College , Cambridge , and University Lecturer in Botany. 
With Plates XXIX and XXX and three Diagrams in the Text. 
"VIONGST the numerous species of the genus Peperomia which are 
JL\. found in South and Central America, a few peculiar species have 
been discovered which are more or less geophilous in habit, having either 
an underground corm or tuber, or a tuberous rhizome. The possession of 
more or less peltate leaves also appears to be correlated with the tuberous 
habit. De Candolle 2 has grouped these species together by means of this 
character, and they form the first subdivision in his arrangement of the 
genus. Dahlstedt 3 , in his recent monograph of the South and Central 
American Piperaceae, follows on the lines of Miquel’s arrangement, and 
places these species in the section Eutildenia of the subgenus Tildenia , 
Miq. 4 The first group of this section, which includes eleven species, is 
distinguished as having £ tuber hypogaeum rhizoma tuberosum,’ and nearly 
all these species, together with some others as yet undescribed, form the 
subject of this paper. 
In the course of my travels in the Andes of Bolivia and Peru from 
January to March, 1903, I found three or four different species of small 
bulbous Peperomias growing, either on the exposed hillsides or in clefts of 
the rocks, at about 13,000 feet above sea-level, and it was partly owing 
to the difficulty of determining the species, and partly to the discovery of 
1 Read in part before the Botanical Section of the York Meeting of the British Association, 
August, 1906. 
2 De Candolle, Prod. XVI, i, p. 393. 
3 Dahlstedt, Stud, iiber Slid- und Cent.-Amer.,^Peperomien, Kgl. Svenska Vet. Akad. Hand- 
lingar, Bd. xxxiii, No. 2, Stockholm, 1900. 
4 Miquel, Syst. Pip., p. 69. 
[Annals of Botany, Vol. XX. No. LXXX. October, 1906.] 
