496 NOTES ON HYBRIDISATION IN THE GENUS EUCALYPTUS, 



of the species in the neighbourhood. For example, it is some- 

 times difficult to say whether a certain tree is E. affinis {sider- 

 oxylon X hemiphloia var. albens), or E. sideroxylon x melliodora, 

 but the matter might be settled effectively if the surrounding 

 Box were noted to be E. hemiphloia var. albens or E. melliodora. 



E. sideroxylon is a species which readily hybridises, with the 

 Boxes, at any rate. Some of the hybrids are so like E. sider- 

 oxylon that it is difficult to distinguish them unless the trees be 

 seen, or a complete suite of specimens, including juvenile foliage, 

 be available. E. sideroxylon has narrow juvenile foliage, and 

 hence is readily seen to be different from a number of broad- 

 foliaged trees more or less related to it. 



E. SIDEROXYLON A. Cunn , and E. leucoxylon F.v.M. 



As I had seen specimens which, in my view, showed 

 hybridism between E . sideroxylon A. Cunn., and E. leucoxylon 

 F.V.M., I wrote to Mr. J. Blackburne, then Secretary of the 

 National Forest League of Maryborough, Victoria, drawing his 

 attention to the subject. In a few weeks he sent me four speci- 

 mens from the Maryborough district. 



No. 1 is typical E. sideroxylon A. Cunn., " Red Ironbark." 

 Timber red, bark furrowed. 



No. 4 is typical E. leucoxylon F.v.M., called by Mr. Blackburne 

 " Smooth-barked Ironbark." Timber pale, bark smooth. I 

 wrote to Mr. Blackburne in regard to his use of the term " Iron- 

 bark " for this species, it being often termed " White Ironbark " 

 in Victoria, although there is often little or no "iron" bark. To 

 this he replied, " I think Victorian writers in speaking of ^^ White 

 Ironbark " undoubtedly referred to E. leiicoxylon. I know that 

 Howitt did so. Another tree, E. Sieberiana, is sometimes 

 alluded to as White or White-topped Ironbark, but I think you 

 can rest assured that E. leucoxylon is the tree generally meant. 

 E. leucoxylon is not altogether a white wood, although the heart 

 wood is much paler in colour than sideroxylon." 



His Nos. 2 and 3 he described in the following words : — 



