Flora of the Ceylon Littoral. 5 
tropics, very largely inland, but particularly on the sea-coast where 
it flourishes specially well. 
1. Pes-caprae-For/nation. This, as we have said, extends to 
within a few feet of high tide-mark. The dominant plant along 
great stretches of coast is Ipomcea biloba (Pes-caprae), the great 
characteristic cosmopolitan plant of tropical sandy shores. It is a 
plant of creeping habit with richly branched stems lying on or just 
buried in the sand, rooting freely and strongly at the nodes, but 
seldom till lateral branches have developed, and with isolated 
petioled leaves, dark-green and glossy, which stand up two or three 
inches above the creeping stems (Fig. 2a), and when the plant is 
growing thickly form a thick verdure covering the sand. The 
leaves are typically deeply two-cleft like a goat’s hoof—whence the 
Fig. 2. Ipomcea biloba (Pes-caprae). A. Normal shoot, the main axis and 
laterals lying flat on the sand, ^nat. size. B. Vorlauferspitz, £ nat. size. 
name. The two lobes diverge at an angle and stand obliquely up like 
the half-closed wings of a butterfly. This constant oblique position is 
no doubt an adaptation to the very strong light to which the plant 
is exposed. Like most pioneer sand-plants, Ipomcea biloba by 
means of its creeping and freely rooting habit binds the loose sand. 
Its apical growth is very rapid, the young stems often running out 
over the bare sand towards high tide-mark in long “ Vorlauferspitze,” 
i.e. quickly growing young shoots with very long internodes and 
rudimentary leaves (Fig. 2b). The covering of the sand with a 
network of unrooted shoots alone tends to check its movement by 
the wind, and very soon the new shoots firmly establish themselves 
