STUDIES IN THE DEVELOPMENT OF THE PIPERACEAE^ 
I. THE SUPPRESSION AND EXTENSION OF SPOROGENOUS TISSUE 
IN THE FLOWER OF PIPER BETEL L. VAR. MONOICUM C. DC. 
DUNCAN S. JOHNSON 
Professor oj Botany, Johns Hopkins University 
SEVENTY-ONE FIGURES^ 
In an account of the seed development of Heckeria umbellaia 
(L.) Kunth (Piper umbellata C. DC) and of Piper medium Jacq., 
published eight years ago (Johnson, '02), these forms were com- 
pared with other angiosperms, and especially with Peperomia 
pellucida. A study of the plant here described was begun at 
the same time. This species of Piper was chosen because, from 
all species available at my collecting ground, the east end of 
Jamaica, this one was markedly distinguished by its climbing 
habit, its unisexual flowers and its immersed ovaries and seeds. 
The detailed investigation of the present species confirms cer- 
tain conclusions reached in the study of the genus Piper, but also 
shows several important peculiarities, especially in the develop- 
ment of stamens and ovaries. 
The material used was collected in Jamaica by W. C. Coker 
in 1900, by the author in 1903 and 1906, by R. K. Miller in 1905 
and by I. F. Lewis in 1906. A fifth lot of material was collected 
in the East Indies by D. H. Campbell in 1907. Obligation isliere 
acknowledged to the above mentioned gentlemen, and also to 
M. Cassimir de Candolle for identifying the plants from Jamaica, 
^ Investigation prosecuted with the aid of a grant from the Botanical Society 
of America and one from the Bache Fund. 
2 Contribution from the Botanical Laboratory of the Johns Hopkins Univer- 
sity, No. 15. 
