120 PODOSTEMACEAE [CH. 



"These plants bear very pretty flowers at this season of the 

 year [September] as soon as they are left uncovered by the 

 subsiding of the waters after the rainy season, but still kept 

 moist by the wash of the water's edge. One small-leaved 

 species has a little white star-shaped flower, on a short delicate 

 stem, which has a slight perfume and proves an attraction to 

 numerous species of wild bees." Im Thurn 1 , again, in his 

 account of the same regions, mentions Mourera fluviatilis and 

 Lads alata as growing "on the half-submerged rocks in most 

 of the falls. As the water decreases in the dry season, the tall 

 spikes of bright pink flowers of the former plant rise from their 

 large leaves, the edges of which are cut and curled into the like- 

 ness of moss, which lie flat on the rocks ; and at the same time 

 and place innumerable tiny pink stars rise an inch or two over 

 the equally moss-like leaves of the Lads." 



The vegetative parts of the Podostemads die very quickly 

 when out of their element, and the flowering and seed-setting, 

 both of which take place with the utmost rapidity when the 

 plants are exposed to the air, represent, as it were, their swan- 

 song. In Lawia zeylanica, Willis 2 has observed that the enor- 

 mous amount of starch stored up in the flowering shoots 

 accounts for the great rapidity with which anthesis and seeding 

 take place. In the case vfRhyncolads macrocarpa, Goebel 3 points 

 out that each inflorescence-bud is enclosed in a cavity formed 

 by the connate union of two leaves. These cavities are full of 

 water, so that the life of the flower-stalks is passed in an environ- 

 ment resembling that of ordinary aquatics inhabiting still 

 water; it is thus not surprising that these stalks differ from the 

 other vegetative organs in developing an aerating system, such 

 as is characteristic of water plants in general. 



Both entomophily and anemophily occur among the Podo- 

 stemads. According to Willis, we can trace a series from certain 

 American Tristichaceae with conspicuous, entomophilous 



1 Im Thurn, E. F. (1883). 2 Willis, J. C. (1902). 



3 Goebel, K. (1891-1893). 



