Laing. — The Norfolk Island Species of Pteiis. 



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Art. XXVI. — The Norfolk Island Species of Pteris.* 



By R. M. Laing, M.A., B.Sc. 



[Bead before the Philosophical Institute of Canterbury, 7th July, 1915.] 



Since drawing up the list of ferns for my paper on the flora of Norfolk 

 Island (Trans. N.Z. Inst., vol. 47, p. 1) I have received a large number 

 of additional specimens from my father, Mr. W. Laing, resident on the 

 island. These necessitate a reconsideration of the species of the genus 

 Pteris. This revision need not include the common Pteridium esculentum 

 (Forst. f.) Cockayne and P. commis, as to whose occurrence on the island 

 all are agreed. The following table shows roughly how Bndlicher's species 

 have been viewed in recent literature : — 



Now, it is probably impossible without direct reference to the type 

 specimens at Vienna to determine with certainty the identity of Bndlicher's 

 plants ; but I think that it can be done more accurately than has yet been 

 done, if fairly full material is available. 



The first important point to consider is the question of the venation, 

 whether forking or anastomosing ; and an examination of Bndlicher's 

 descriptions . gives the following results: Veins forked — P. Baueriana, 

 P. Kingiana, P. Trattinickiana; veins anastomosing — P. Brunoniana, 

 P. comans, P. Zahlbruckneriana. It is true that no mention is made in 

 the case of P. Baueriana as to whether the veins are free or anastomose ; 

 but as the plant is said by Bndlicher to be very near P. tremula, in which 

 the veins are free, we may consider both the same in this respect. 



A. Species with Forked Venation. 

 (a.) Pteris tremula R. Br. = Pteris Baueriana Dies., Bndl., No. 37. 

 Let us consider the forms with forked venation first. I have three 

 of these which agree well with Bndlicher's descriptions of P. Baueriana, 

 P. Kingiana, and P. Trattinickiana. I have little doubt that they 

 are distinct species. Bndlicher's diagnosis scarcely serves to separate 

 P. Baueriana from P. Kingiana, but his detailed description enables this 

 to be done with a fair amount of accuracy, and there seems to be but 

 little doubt that P. Baueriana Dies. = P. tremula R. Br. In this I 

 foUow Maiden, though Bndlicher himself admits that P. Baueriana is 

 " Pteridi tremtdae R. Br. proxime afi&nis." Hooker and Baker do not 

 mention this species. 



A comparison of specimens from Norfolk Island of this plant with the 

 New Zealand Pteris tremula shows that the two forms are almost indis- 

 tinguishable. 



* Specimens of these and other Norfolk Island, plants collected by me will be found 

 in the Canterbury Museum. 



