294 



AFFINITIES. 



This is another of the few species which flower in the opposite-leaved or juvenile 

 stage (See Journ. Roy. Soc. N.S.W., xlviii, 424 (1914) ). If described from the type 

 only, it might have been looked upon as homoblastic species, but the additional 

 material I have quoted shows that, like E. praecox {loc. cit.), it is heteroblastic, like 

 the vast majority of species of this genus. We can only say that it is an example of 

 retarded heteroblasty. 



Other instances of retarded heteroblasty in Eucalyptus are :— 

 E. Risdoni Hook, f . See Plate 32 of the present work. 

 E. Gillii Maiden. • See Plate 67, op. cit. 

 E. cinerea, F.v.M. See Plate 89, op. ciL 

 E. cinerea F.v.M., var. multiflora. Plate 90, op. cit. 

 E. melanophloia F.v.M. 



In the absence of a complete suite of specimens and full data as regards 

 E. Houseana, I am only able to suggest relationships to the following species at 

 present :— 



1. With E. alba Reinw. 



The flower-buds of E. Houseana may resemble those of E. alba a good deal. 

 Exceptionally the leaf -blade may resemble that of E. Houseana in shape and venation, 

 but that of E. alba is not sessile at any stage, not cordate at the base, and is often gross 

 in size. Speaking generally, the foliage of E. alba is not pale-coloured, whether arising 

 from glaucousness or not. Both species flourish in moist, low-lying localities. 



2. With E. elavigera A. Cunn. 



It differs from this species in the hairiness of the leaves (particularly) in young 

 specimens, so common in E. elavigera, in the numerous flowers, in the great length of 

 the peduncles and pedicels, and in the clavate shape of the buds of E. elavigera. The 

 shape of the leaves and the venation may, exceptionally, be a good deal similar in the 

 two species. (Original description, p. 321.) 



3. With E. fceeunda Schauer, according to Mr. Fitzgerald himself. 



E. fceeunda is figured and described in Part IV. I arn not able to indicate close 

 affinities, and leave the matter for further enquiry. 



