Manchester Memoirs, Vol. Iviii. (1914), No. 14. 



XIV. Juvenile Flowering in Eucalyphis globulus. 

 By Professor F. E. WEISS, D.Sc, F.L.S. 



(Read October jth, igrj. Received fo7- publication, September i2:h, igi4) 



It is a well known fact that the young plants of the 

 Blue Gum {^EncalyptJis glolndus) have very different foliage 

 from that which is characteristic of the mature plants. 

 In the former the leaves are arranged in pairs opposite 

 each other, they possess no leaf stalks and their blade is 

 horizontally expanded. The foliage is covered with a 

 waxy bloom which gives it the peculiar greyish tinge. 

 This immature foliage persists for many years. Under 

 cultivation in the greenhouse, particularly when pruned 

 back, plants may grow for fifteen or more years without 

 showing any trace of the characteristic foliage of the 

 mature plant. When this latter stage has been reached 

 the leaves are found to be inserted alternately on the 

 branches ; they are pendant, owing to the possession of a 

 distinct and slender leaf stalk, and the leaf is sickle- 

 shaped instead of possessing the bilateral symmetry of 

 the juvenile foliage. The mature foliage, owing to the 

 pendant position of the leaves, is undoubtedly better 

 adapted to resist drought and intense insolation than is 

 the foliage of the juvenile plant, which probably grows 

 for a considerable time in the shade and shelter of taller 

 trees. Such differences in the foliage of immature and 

 mature plants are not at all uncommon and among 

 Australian plants belonging to a widely different natural 

 order the Acacias ma)' be cited as another example, 



October 2isl, 1Q14. 



