DESCRIPTIONS OF N.Z. FERNS. 63 



is one very distinct and beautiful variety, named by Mr. Colenso " var. hirtum " which 

 has the hairs of a light yellowish brown, particularly when young. It is not uncommon. 



HYMENOPHYLLUM SUBTILISSIMUM. (Hi-men-o-fil-lum sub-ti-lis-sim-um.) 



PLATE XV., No. 2. 

 This is one of the most lovely of our Hymenophylla, its name bespeaking it as 

 " the most delicate." It grows in dense mats among long moss, on tree trunks, rotten 

 logs, and particularly on stems of tree-ferns, in deep damp gullies. It has smooth 

 creeping, slender rhizomes, and very short, stout, downy stipes. The fronds are oval, 

 oblong or lanceolate, and vary from an inch to nearly a foot in length, being usually 

 however about three to four inches long, and bi or tri-pinnate. The pinnae are broad, 

 numerous, pinnatifid, and overlap each other; the secondary ones lanceolate, and 

 deeply cut into narrow lobes. The texture is so thinly membranous as to be almost 

 transparent, and the colour of so yellowish a green that the fern was formerly called 

 " aeruginosum (ae-ru-gin-o-sum)," i.e., brassy. Therachis, costae and veins are thickly 

 studded with short bristles growing in clusters, and similar clusters are found on both 

 surfaces of the frond, and more plentifully round the edges. The sori are very 

 numerous, and placed on the ends of the lobes. The involucres short, very broad, and 

 bristly. The fronds generally hang down. This fern is found all over the Colony, 

 certainly up to a height of 2000 feet above the sea and appears to be particularly 

 luxuriant in Stewart's Island. It also occurs at the Chatham Islands, Chili, Chiloe, 

 Juan Fernandez, and Tristan d'Acunha. Its fronds turn reddish brown when dry. It 

 grows well in a case or under a bell glass, but care is required to keep the moss in 

 which it grows wet enough and yet not saturated with moisture, lest the fern should 

 rot. The air around it cannot be made too moist. The only varieties seem to be 

 those arising from the different size and shape of the fronds in various localities. The 

 fronds are occasionally forked. 



HYMENOPHYLLUM RUFESCENS. (Hi-men-o-fil-lum ru-fes-sens.) 



PLATE XV., No. 6. 

 This is a small fern found growing in mats, on tree-trunks at high levels. It has 

 slender, wiry, creeping rhizomes with few scales, and an extremely long hair-like stipes, 

 far longer than the frond Itself, though the length of the whole seldom, if ever, exceeds 

 three inches. The stipes has a very few short scattered hairs on it, but these gener- 

 ally fall off. The rachis, costae, veins, and whole surfaces of the frond are thickly 

 dotted over with long silky hairs, which grow singly, and there are similar hairs round 

 the margins. Some of the hairs seem deciduous. Frond rather broadly triangular, 

 and upper part of rachis winged. The lower pinnae are stalked and broadly triangular 

 or rhomboidal ; the next also stalked but narrower, and the others sessile and bluntly 



