214 
WILLIS ; PODOS'L'KMACBÆ 
from leafy axial cupules of varying depth ; leaves and 
pedicels varying in length, apical leaves dimorphic. 
Thallus frondiform, rootless, closely attached to the rock by root 
hairs to the tips of the growing apices, often reaching 20-35 cm. in 
diameter, spreading in all directions, about 0’5 mm. thick, hard, and 
siliceous, deep crimson or green in colour when alive, much branched, 
with flabelliform or ribbon-like apical lobes ; the branches to 10 mm. 
broad, diverging at a moderate angle from the main stem, closely 
crowded or scattered. Leaves very numerous, both at the growing 
points, where they are borne directly on the thallus, and on the older 
parts of the thallus, where they occur in endogenous rosettes, linear 
to linear-ovate, acute, very thin and delicate, 1-15 mm. long, with 
white mesial line in lower part, attached by broad base. Apical leaves 
dimorphic, the lateral ones distichous on the edges of the thallus, 
broader, the upper linear, more numerous, irregularly arranged on the 
upper surface. Flowers very numerous, closely crowded along the 
edges of the thallus, solitary, emerging from small terminal cupules, 
rarely on upper surface. Cupules ovate, about 0 5-2-0 mm. deep 
and 1‘0-L5 mm. broad at the mouth, axial, densely leafy above and 
on the edges, with thick upper and thin lower wall, free from 
thallus below, more or less ascending, bristly when dry. Peduncle 
from base of cupule about 2-6 mm. long when the flower opens, 
coated with pellucid cellular tissue which falls after flowering. 
Flower erect on the peduncle, often only emerging from the cupule 
when the water falls so as to expose the tip of the latter, which often 
remains closed so long as submerged. Perianth segments united for 
2/3 of their height. Ovary ellipsoid subsessile, stigmas linear. 
Capsule about 2 mm. long, ellipsoid. 
On smooth rocks in rapids, Ceylon, S.-W. India from 
Travancore to Bombay, to 2,500 feet, common. 
This is an extremely variable plant, and specimens from 
many localities have been examined. Each locality seems 
to have its own form, but after close examination of all 
I incline to group them into four varieties, partly geo- 
graphical. 
L, zeylanica Qardneriana ; Tristichaceylanica, — 
Thallus large, with flabelliform apices; leaves 1-3 mm. 
long ; rosettes numerous. Cupules ovate, about l*5-2*0 
mm. deep, shortly bristly in dry specimens. Pedicel 
ultimately about 6 mm., long. Fruit ellipsoid, dark 
brown. 
