•59 



NOTES ON THE FERTILISATION OF SOME 

 AUSTRALIAN AND OTHER PLANTS. 



By a. G. Hamilton. 



(Plate XXVI.) 



PITTOSPOR£.a:. 



PiTTOSPORUM UXDULATUM, Atidr. — I have (3) given an account 

 of the two forms of flowers noticed in this plant — 1st, those 

 with perfect stamens and pistils; 2nd, those with perfect pistils, 

 but having stamens very short and converted into nectaries, and 

 not functional as pollen-bearers. Since then, I have seen a tree 

 in Dr. Lee's garden in Wollongong which sprang up as a seedling 

 among ferns transplanted from the bush. In this tree the 

 stamens are perfect but the pistil is imperfect and never sets 

 seed. This completes the series of forms. 



T. Kirk (2, p. 81) says of Pittosporum eugenioides, A. Cunn., 

 *' In this species the flowers are in many specimens practically 

 unisexual : although both stamens and pistil are invariably 

 present, one or other is abortive. The perfect stamens have 

 longer and more slender filaments, and produce abundance of 

 pollen : the imperfect stamens are carried on shorter, less slender 

 filaments, and produce but little pollen. The pistil exhibits but 

 little variation. Flowers with "perfect and imperfect stamens 

 may be produced on different trees, or both forms may be found 

 on the same tree associated with perfect flowers : in the former 

 case the trees are practically dioecious. Other New Zealand 

 species of Pittosporum exhibit the same phenomenon." 



Pittosporum undulatum has manifestly reached a farther stage 

 of differentiation, as the various forms are never found on one 

 tree, so far as my experience extends; the anthers in the second 



