DESCRIPTIONS OF N.Z. FERNS. 57 



HYMENOPHYLLUM RARUM. (Hi-men-o-fil-lum ra-rum.) 



PLATE v., No. 5. 

 This fern is of a very light bluish green colour, growing in dense mats on the 

 trunks of trees, usually on those which have astringent bark, such as hinau or tawhero, 

 but sometimes on tree-ferns. Rhizomes black, smooth, and threadlike or wiry. The 

 fronds vary from one inch to eight or nine inches in length, but the stipes is very long 

 and slender in proportion to the frond itself, in fa£t quite hairlike. Frond, usually 

 bipinnatifidly and deeply lobed, and oblong in form. Pinnae numerous, and overlapping 

 each other, the lower ones sometimes stalked. Lobes short and broad. Texture very 

 thin. Sori terminal and covered by very large, broad, flattened involucres with entire 

 edges and sunk in the ends of the lobes. This fern only occurs in very damp shady 

 places, usually beside streams in the bottoms of gullies, and at all levels up to about 

 3000 feet above the sea. The fronds hang downwards, and the only way to grow this 

 fern is to get a piece of the stem or bark on which it is seen, and place it upright in a 

 case, or under a bell glass, in a shady place, standing the pot in a saucer of water, to 

 keep the atmosphere cool and moist. A widely-spread fern, extending from Japan to 

 the Auckland Islands, and from Africa to South America, but nowhere very plentiful. 

 Mr. Colenso's " Hymenophyllum imbricatum " is a fortn with very overlapping pinnae 

 and edges slightly wavy. It is not uncommon. 



HYMENOPHYLLUM FLABELLATUM. (Hi-men-o-fil-lum fla-bel-la-tum.) 



PIATE XIX., No. 6. 

 This fern is usually found in the same situations as the last, and often on the same 

 tree. It, however, more frequently occurs on the roots than the trunks of trees ; and 

 is occasionally met with on rotten logs. Its rhizome is creeping, and thickly covered 

 with light brown downy scales. It is also less densely matted than the last. Stipes 

 and rachis black and shining. Frond oval, usually from one to two inches long, but 

 occasionally as much as fifteen or eighteen inches. The pinnae are stalked, and so 

 numerous and closely set as to overlap. They are fan-shaped, whence the name, and 

 divided into broad lobes, radiating more or less from the stalk, and generally 

 pretty equal in length. In large fronds, however, the middle ones are often consider- 

 ably elongated, and it is sometimes not easy to distinguish between them and those of 

 long oval examples of Hymenophyllum demissum, till the rhizome is examined. The 

 smell of dried fronds, however, is different. Sori numerous, enclosed in small oval 

 involucres, with entire edges, sunk in the ends of the lobes, but less so than in the last- 

 described species. Texture thin. This fern is also called " Hymenophyllum nitens," 

 on account of its shining glossy appearance. The fronds always hang downwards and 

 it requires to be grown in the same manner as "Hymenophyllum rarum " for this 

 reason. It also occurs in Australia and the Auckland Islands. 



