314 



la. Stem-clasping and Crowded. 

 This sub-head may prove convenient for purposes of rough classification. 



E. aspera. E. pruinosa. 



E. maerocarpa. E. vernicosa. 



E. Muelleri. 



Connate or Perfoliate. 



This is a question of fusion of two leaves by their bases, around a common axis 



or stem, not petiole. 



It even happens in a small number of Eucalypts, that these opposite (i.e., sessile and opposite 

 during a long period of the youth of the tree) leaves unite by their base and become what is called connate, 

 forming then a single piece, which is traversed through its centre by the stem or the branch. This new 

 disposition of the foliage is sometimes transitory, as in E. Risdoni, sometimes permanent as in E. gamophylla, 

 E. perfoliata, and perhaps some others. (Naudin, 1st Mem., 347.) 



Mueller in " Eucalyptographia '"' under E. cjamophylla has a note on E. perfoliata. 



The concrescence of the leaves by pairs in all stages of growth occurs, so far as known, only in 

 E. perfoliata, if even in that rare and little known congener this coalescence should prove also exceptional. 



If Plate 180, Part XLIV of the present work be referred to, it will be seen that 

 this species is not perfoliate throughout life. 



Besides those species mentioned by Naudin as showing perfoliation, we may 

 include E. pulvenilenta, E. Perriniana. A figure of a perfoliate leaf (E. Perriniana) 

 may be seen at fig. 11, Plate 83, Part XIX (erroneously as E. cordata). 



See fig. la, Plate 32, Part VI, for the connate leaves of E. Risdoni encircling the 

 stem. This particular twig shows flowers and fruits, the leaves still exhibiting juvenility. 

 Perfoliate leaves of E. gapiophylla will be found figured on Plate 147, Part XXXV. 



Scars on branches and trunks. — As growth proceeds, the rachises increase in 

 diameter, and stretch the bases of the perfoliate leaves. The leaves are persistent for 

 a long time, and leave circular ragged scars or fragments on the branches and on the 

 main trunk, even when the latter attain several inches in diameter. This character 

 seems rare in Eucalyptus. I have seen it in E. pulverulenta (see Part XXI, p. 15), 

 but only in a very marked manner in E. Perriniana. It, however, probably occurs in 

 all perfoliate species. 



Fusion of leaves by margins. 



We have already spoken of fusion of leaves by their bases, but we may have 

 fusion taking place at other parts of their margins. 



This is an unusual occurrence in Eucalypts; the following are the only cases 

 known to me. Additional instances should be searched for : — 



1. E. numerosa, Bega district (James Taylor, May, 1918). 



2. E. maculosa, Blackheath (E. H. Cambage). 



3. E. cordata. In specimens groAving in the Botanic Gardens, Sydney, the laminfe 

 are sometimes fused both basally and laterally. 



At Part XLIX, p. 279, we have already spoken of Cohesion of Branches. This 

 fusion may be referred to as " Cohesion of Leaves." 



