48 DESCRIPTIONS OF N.Z. FERNS. 



a vein or in fork of a vein. Receptacle mostly elevated, and frequently hairy. 

 Generally has the arborescent habit of Cyathea and Hemitelia, but is destitute 

 of involucres. Veins simple or forked, free. Our only recognised species is 



ALSOPHILA COLENSOI. (Al-soph-il-a Co-len-so-i.) 



PLATE III., No. 4. 



So called after its discoverer, the Rev. W. Colenso, of Napier, and confined to 

 New Zealand. The fern usually thus called is only found near the snow line, in the 

 North Island, but occurs at lower levels in the Middle one, descending to 1500 feet in 

 Otago. Though classed as a tree-fern, it is not truly so, as the caudex lies on the 

 ground, with only its end, which is much thinner and softer than the rest, turned 

 upwards. As this end thickens (it apparently never exceeds one and a half inches 

 thick), and hardens, it lies down, and produces long hard wiry root-fibres, which point 

 towards the crown, instead of away from it, as the root-fibres of ordinary caudices do. 

 These root-fibres enter the ground, and hold the caudex fast. If, in travelling along, 

 the end of the caudex encounters a fallen log or other obstacle, it climbs over it, and 

 descends to the ground again on the other side to continue its course. Thus the 

 crown of the plant is often some distance from the original root. It is said that the 

 caudex occasionally becomes erect ; but though I have seen thousands of acres of the 

 fern, I never could find a plant with a naturally erect caudex, and have tried for years 

 to compel a cultivated specimen to produce one. Of course when climbing over an 

 obstacle, or when jammed in an angle of rock, a caudex may be forced to ascend for 

 a time, but this is under unnatural conditions. Mr. G. M. Thomson, of Dunedin, 

 told me he had once seen a caudex growing erect ; but the plant was situated in a 

 dense low mass of bramble, and had had to struggle upwards for light and air, so was 

 not a fair example. The Rev. W. Colenso assures me that the ferns found by him on 

 the Ruahine mountains had caudices sometimes yft. high ; and Professor Kirk and 

 Mr. T. F. Cheeseman also mention having seen plants with caudices. I conclude, 

 therefore, that either there are actually, in different places, two ferns with similar 

 foliage called by the one name ; or else the one plant has curiously reverted to the 

 arborescent type in certain localities. The crown of the plant consists of but few 

 fronds, which are never more than 2ft. to 3ft. long, and very broadly lanceolate. The 

 stipes is very short, almost wanting, in fact ; and in the North Island plant both it 

 and the rachis and the costae of the pinnae are of a light brown colour, smooth, with 

 a few darker brown scales below, and slightly velvety above. The pinnae are 

 arranged alternately, and are so close together as to overlap considerably. The lower 

 ones are very short, and so deflexed as to lie flat against the face of the stipes, and 

 hide it. The pinnules are numerous, and deeply cut into broad sub-falcate lobes, with 

 their edges entire or nearly so. The colour is a soft bright yellowish green, turning 



