THE ANGIOSPERMAE 



1555 



Plume formation displays the same kind of variation that is shown by 

 wing formation and the two often occur together, supplementing one 

 another. The style itself is often beset with long silky hairs which form a 

 plume, as in Clematis (Fig. 141 6) and some species of Anemone, where the 

 hairs grow greatly in length as the akenes ripen. Some other species of 

 Anemone of tall habit have hairs on the carpel itself, which form little 

 woolly plumes around the minute akenes and are effective over fairly short 

 ranges (Fig. 141 7). Grass fruits are not only distributed with the aid of 

 the glumes but also form plumes of hairs, either attached to the glume 



Fig. 1417. — Aiiewotie japoriica. Mass of akenes from a single 

 flower, each surrounded with flurtV plumes. 



itself or coming from the rachilla below the glume and growing much longer 

 than the latter. Good examples of plumed grasses are Phragmites, Saccharum, 

 Calamagrostis, all with small fruits. In Stipa it is the long awn which bears 

 the plumes and, in addition, the awn is twisted at the base and serves for 

 seed burial by its hygroscopic movements. Plumes of axial hairs also 

 surround the fruit in Platanus and Typha. Their hygroscopic movements 

 prise apart the massed akenes and then act as parachutes. 



