Plate 243.— ASPLENiUM HOOKEHIANUM. 



Family FILICES] [Genus ASFLENIUM, Linn. 



Asplenium Hookeriaiium, Cul. in Tu;sin. Jour. Aal. ^sct. (iCi-iOj 109 ; (Jluxsem. Man. A'.Z. Ft. 

 992. 



The discovery of Asplenium Hoo/reria7ium is vividly recoiinled by 

 Mr. Colenso in liis " Excursion made in the Nortliern Island of New Zea- 

 land," published in 1S46 in tiie second volume of the " Tasmanian Journal of 

 Natural Science." In this fascinating memoir he describes a three-months 

 journey from the East Cape and Lake Waikare-moana to Kotorua and Tau- 

 ranga, returning to the Bay of Islands via the Thames Valley, the Waikato 

 River, and the Kaipara. Giving an account of his journey up the Thames 

 Valley after leaving Matamata, he says, " We entered a romantic valley, called 

 by the Maoris Hinuera. This valley has on either side high and perpendicular 

 volcanic rocks, composed of a conglomerate of pumice, scoria, obsidian, &c. 

 . . . At 2 p.m. we halted to dine under a large and pensile crag, which, 

 jutting out from the rocks on the north side, overhung our path. Here 

 beneath this rock I discovered an elegant Asplenium {A. Hookerianum, 

 n. sp.). I did myself the honour and pleasure of naming this graceful fern 

 in memorial of my much-respected and talented friend J. D. Hooker, Esq." 

 The remarkable hat-bottomed valley mentioned by Mr. Colenso leads directly 

 to the Thames River from the valley of the Waikato about eight miles above 

 Cambridge, and is supposed by many geologists to indicate the bed of the Wai- 

 kato when it discharged into the Hauraki Gulf instead of following its present 

 course to the west side of the Island. 



Attention having once been directed to Asplenium Huoherianum it was 

 soon found to have a fairly wide distribution, ranging from Kaitaia to the 

 south of Otago, although it is sometimes absent from areas of considerable 

 size. It is usually found on the faces of inland cliffs, or on steep shaded 

 banks, and does not, as a rule, occur in dense forests. Like all its allies, 

 it is exceedingly variable, and manv diverse views have been held as to its 

 limits and systematic position. A finely cut variety with linear segments 

 to the pinnae has been described by Sir J. D. Hooker as a distinct species 

 under the name of A. Colensoi; but, as Mr. Field has pointed out ("New 

 Zealand Ferns," p. 120), not onlv do the two varieties grow iutcrmixed, but 

 sometimes fronds of both varieties occur on the same plant. 



According to Mr. Bentham, Aspleninm Hooherinnum is found in both 

 New South Wales and Victoria as well as New Zealand. T have had no 

 opportunity of examining Australian specimens. 



Plate 243. Asplenium Hookerianum, drawn from specimens collpcted in the Wangapeka Valley, 

 Nelson. Fig. 1, under-surface of pinnule : 2, under-surface nf another pinnule ; 3, small portion of a 

 pinnule, showing a sorus with its indusium ; 4, a single sporangium. (.\11 enlarged.) 



