





COtflFER^ 



261 

















Sometimes leaves of a similar character to the true primordial 

 leaves occur on the adult plant, either universally, as in some of 

 the Retinosporas before alluded to, or in association with leaves 

 of the ordinary appearance, when the foliage becomes in conse- 

 quence dimorphic. Thus, in Juni 



*erus sinensis. Uunressus 



carpa, Metinospora leptoclada (hort.), &c, it is very common to 

 find on some shoots small ap pressed leaves and others spreading^ 

 relatively long and awl-shaped*. The two forms of leaves 

 sometimes occur on the same branchlet, and the degree of con- 

 crescence is relatively small. A similar thing occurs in some 

 species of Frenela f. In these cases the long awl-shaped leaves 

 are of the same form and have the general appearance of the 

 primordial or protomorphic leaves, as is clearly seen in seedling 

 plants of Juniperus phcenicea, in which in the adult state the 

 four-cornered branches are covered with densely crowded, ap- 

 pressed, 4-ranked leaves, while the seedling: plant has linear 















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 ■ 



r 



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r- 







spreading leaves. 



In some species of Dacrydium, as in D. elatum, Colensoi, and 



Kirkii 



remarkable differences between the young 





leaves, which are spreading and more or less elongate, and the 

 mature foliage, which is short and appressed J. Kirk, in his 

 monograph of Dacrydium §, makes two divisions of this genus. 

 In the one, the young leaves are terete and spreading, and 

 pass by gradual transitions into the mature imbricating state, 

 while in the other the young leaves are linear, flat, and pass 

 abruptly into those characteristic of the adult condition. 



The genus Podocarpus presents illustrations of similar diversity ; 

 thus, in P. cupressina and P. dacrydioides, &c. ||, the leaves on 

 the younger branches are spreading, broadly linear and falcate, 

 while in the more mature state they are polystichous, small and 

 appressed. 



It is interesting to notice that Dioscorides, lib. 1, cap. 88, recognized the 

 two forms :— " Sabina duorum generum est, una foliis cupresso similis spinis 



norridinr o-mvifo*. /-vi~« a .,™.;~ ~* 4Vx«.-~ ftna »~u^~ oaf nnnotiv, hrpvitatis aute sese 

















tamarisci 



W •**v«v*4vtlli^iU J1AUV11U •••••• tliWld UC*A**C*l *» v * »w~— v 



Chabraeus, Stirpium Icon. p. 72, where both forms are figured. 



t See Pasquale, loc. ante cit, and Brongniart et Gris in Bull. So 

 France, xvi. p. 327. 



t Hooker, Icones Plantarum, tab. 1219. 



§ Kirk in Transact. N.-Zealand Institute, xi. (1877) p. 883 ; also 

 • Forest Flora of New Zealand ' (1889), with many illustrations. 

 I Brown and Bennett. Plant. Java, 1. 10. 



See also 



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