DESCRIPTIONS OF N.Z. FERVS. 45 



though I do not know which, is reported from Westland. The latter form is plenti- 

 ful near Dunedin, where it is regarded as a form of Hemitelia Smithii. There is also 

 there a form of it which exa6lly resembles C. medullaris, with rather slenderer stipes 

 and rachis than usual, but with white scales instead of black, apparently a connecting 

 link. All forms of this fern can be easily cultivated, but require more shade and 

 shelter than C. medullaris. 



CYATHEA DEALBATA. (Si-a-the-a de-al-ba-ta). 



THE "SILVER TREE-FERN." MAORI NAME, " PONGA." 



PLATE X., No. 2; and PLATE XXIX., No. 3. 



This plant may generally be at once identified by the white undersurface of the 

 fronds, though this is occasionally wanting. The caudex is often forty to fifty feet high, 

 stout, and covered all over with the light brown ends of old stipites, which stand out at 

 an angle to a length of about six or eight inches, and retain their place till they are 

 buried among the aerial root-fibres. The fronds are occasionally ten or twelve feet 

 long in young plants and sheltered situations, but are mu^h shorter in crowns that rise 

 above the general vegetation in a forest. Stipes short and only moderately stout, 

 usually white below and green above. Rachis and costae the same, but getting 

 gradually darker towards the top of the frond, where the latter are often almost black 

 on their upper surface. When they first appear in spring, the stipes rachis and costae 

 are covered with dense brown scales which give the young fronds a dirty and unattrac- 

 tive appearance ; but these soon drop off and only leave a slight roughness in their 

 place. Towards the upper part of the frond, however, the upper surface of the rachis 

 and costae is often covered with a yellowish down, which is easily rubbed off. Frond 

 broadly lanceolate, and often narrowing to a longish point. Pinnae shortly stalked, 

 and often narrowed into a sort of point towards the end. Secondary pinnae also shortly 

 stalked, and very generally terminating In long points. Pinnules broadly sessile 

 throughout, or only the very bottom ones narrowly so, or partially stalked, i.e., cut 

 down to the mid-rib on one side, while still broadly sessile on the other. Edges entire 

 or only very faintly indented, and curving over as sori develop, as shown in enlarged 

 pinnule. Colour generally silvery white below (whence the name " dealbata," 

 whitened), and dull green above. There are no hairs. The sori are small and nearly 

 black, but so thin that they soon burst, and show the yellow capsules intermixed with 

 the hairs of the receptacle which is club-shaped. This fern occurs as far south as 

 Canterbury and Westland, but beyond that it seems absent, or nearly so. It is also 

 reported from Penang and Lord Howe's Island. This fern is a favourite one with the 

 Maoris, who prefer its fronds to any others to spread on the floors of their huts for 

 bedding. This is no doubt partly owing to their thin texture, and partly to the 



