146 PROTEACEAE 



points, hence the more vivid glittering of the silver trees 

 in summer when the South wind ruffles their leaves. 



The female inflorescence of Lcucac/ctu/ro/i develops 

 into a cone. In most species the nuts are winged, while 

 in the others the persistent perianth assists in their 

 distribution. 



Winged fruits are frequent in various families, but 

 the mode of dispersal of Leuca(/e7i(/ro?i argcjiteum^ 

 L. plumosum and a few others is unique. 



While the cones of pines and firs become pendulous 

 during their development, those of Leucadendron remain 

 upright, hence the seeds cannot leave the cones unless the 

 branches are shaken by a strong wind. When this takes 

 place they do not, however, drop straight to the ground, 

 like the seeds of the stone pine, for the modified perianth- 

 segments support them. In the flower the lower part of 

 the perianth is tubular, but during the growth of the nut 

 this portion has developed into a membranous coat, while 

 the segments have been changed into large feathery wings. 



The cones ripen late in autumn (April, May); during 

 dry and windy weather their scales curve back and allow 

 the nuts to escape. In doing so the membranous coat 

 splits from below and glides to the end of the persistent 

 style (Fig. 76, A, 1). Here, however, it is retained by the 

 knobbed stigma, and as on leaving the cone the calyx 

 spreads its feathery segments horizontally, the nut remains 

 suspended between the four wings like an aeronaut from 

 his parachute, to be carried away by the wind to colonise 

 new ground. 



Plate 28. 



Leucadendron argenteum (L.) R. Br. 



Male- flower-heads, one with buds and the other with open flowers. October. 

 1/2 nat. size. 



