306 WILLIS : MOEPHOLOGY OF THE PODOSTEMACEÆ 
development of flowers all at one season, and absence of 
intercellular spaces ; the plant is finally destroyed by ex- 
posure to the air, leaving only the seeds and perhaps a few 
submerged thalli to tide it over the dry season. 
LA WIÄ. 
[(TERNIOLA), Tul. ; Willis, Rev. Podost. Ind., Ann. Perad. L, p. 209.] 
This peculiar little genus is confined to Ceylon and 
Western India, where it is extremely common in suitable 
localities. In Hooker’s flora seven species are recognized on 
Weddell’s authority ; of these, I have transferred L. 
ramosissima to the genus Tristicha, while of the remaining 
six, three proved to be completely identical with forms 
described under other names, thus reducing the genus to 
Tulasne’s original three species, zeylanica, pulchella, and 
iongipes. I hardly consider these latter two separable, as 
the length of leaves and pedicels are, as we shall see below, 
extremely variable characters ; I have therefore united 
them, and have also united the Indian forms to the Ceylon 
ones to form the one species L. zeylanica, of which there 
are many varieties and sub-varieties. As a temporary 
measure, pending detailed knowledge of material from 
many sources, I have divided the species into two Ceylon 
and two Indian varieties, Gardneriana, Parkiniana, malaba- 
rica, and konkanica, respectively. 
The morphology of the vegetative organs has not been 
accurately described in this genus. The accounts of 
Gardner (12), who first discovered it, and of Tulasne, though 
accurate as far as they go, are very little more than descrip- 
tions of the flowers. The thallus adheres so closely to the 
rock that it is very difficult to detach more than minute 
fragments for herbarium specimens, and as the flowers are 
usually most numerous on the older parts, it so happens 
that practically none of the existing specimens show the 
growing points or the mode of growth of the thallus. 
Tulasne, indeed, noticed that not all the leaves were in the 
rosettes that are the most conspicuous feature of the upper 
