BOTANY OF THE CEYLON PATANAS. 331 
variable in size on the same plant, and on comparatively long 
petioles. In bright sunlight the leaflets move into a profile posi- 
tion, though the mauner of doing this is not the same in all the 
leaves belonging to the same plant. The petiole appears to rise in 
all cases : the leaflet in some cases merely twists on its pulvinulis, 
so as to present an edge to the sky; in other cases the leaflet 
assumes a vertieally hanging position; or, again, it may become 
erect on the top of the nearly erect petiole. 
Andropogon zeylanicus.—This grass is very plentiful on the 
patanas at about 5000 feet. In bright sunlight the erect leaf 
closes on the midrib as a hinge, so that the ventral surfaces of 
the two halves come into contact. 
(4) Leaves which show sleep-movements, but were not 
observed to move into a sun-position. 
Pycnospora hedysaroides and Atylosia Candollei show sleep- 
movements of the leaves, of the same nature as those so well 
known in Ozalis Acetosella, etc. (52). 
A plant deserving special notice by reason of its remarkable 
habit is Hedyotis verticillaris (Rubiacem), which occurs abundantly 
at 6000 feet and higher elevations. This species grows grega- 
riously, and eovers wide patches in wet places on the patanas; its 
aloe-like habit distinguishes it from all other members of its 
natural order. Its leaves are all radical and erect, or nearly so, 
forming a hollow rosette, in the concavity of which water to a 
considerable amount is retained by the close-fitting bases of the 
leaves. The stipules are lanceolate structures, from 1 to 2 inches 
in length, and bear numerous shortly-stalked glands on their 
margins; they are immersed in the water which the cup contains, 
a position which suggests that they may have an absorptive 
function. The fibrous remains of old leaves persist round the base 
of each plant and retain a considerable amount of water. A similar 
persistence of the remains of dead vegetative parts is found 
in several of the grasses—'' Tunika-Grüser" (53)—Cyperacea, 
Eriocaulonacez, ete. 
Shrubby plants growing in certain situations on the patanas 
are considerably affected by the S. W. wind, which is often very 
strong, and always more or less constant for six months in 
the year. This is particularly the case in the valley in which 
the Sita Eliya and Hakgala patanas are situated, which has 
an east and west trend, falling rapidly to the east. Here 
we find a much greater devolopment of foliage and flower-buds 
LINN. JOURN.— BOTANY, VOL. XXXIV. 2A 
