FERNS. 



287 



long their cultivation will extend considerably. A 

 large collection can he grown in a comparatively 

 small structure, and will thrive with very little 

 attention, provided that the essential conditions 

 obtain, viz., continuous shade and moisture. 



HymenophyUums are found in all temperate and 

 tropical climates, and, according to the "Synopsis 

 Filiciun," there are about eighty species. Various 

 authors, however, with very different views as 

 to the limitation of genera and species, consider 

 that Hymenophyllum. and Trichomanes — as under- 

 stood here — comprise no less than some two dozen 

 genera ; the eighty species of Hymenophyllum, too, 

 are by the same writers multiplied into more than 

 five times that number. Many of the species are 

 almost ubiquitous — the two representatives of the 

 genus in the British flora may be cited as exam- 

 ples — and, as is almost sure to be the case, they 

 exhibit a very considerable range of variation in 

 size, habit, &c., according to the widely-different 

 conditions as to temperature, &c., under which they 

 exist. These purely geographical forms are regarded 

 as distinct species by many botanists. 



The principal character by which Hymenophyl- 

 lum may be distinguished from Trichomanes, resides 

 in the involucre ; that of the first-named genus being 

 two-valved, whilst in the latter it is united into a 

 cup. Both affect moist, shady places, near water- 

 falls, trunks of trees, and dripping rocks. 



The following selection comprises some of the 

 best and most distinct species in cultivation. 



S. aruginosum is a rare species, a native of the 

 island of Tristan d'Acunha; the tripannitifid, co- 

 piously hairy fronds measure some two or three 

 inches in length, by an inch or less in breadth ; in 

 outline they are lanceolate or ovate-pointed. 



H. asplmiioides, from tropical America, is easily 

 recognisable by its peculiar habit of growth; it has 

 rather large pendulous fronds, oblong in general 

 outline, and pinnatifid to within a short distance of 

 the rachis ; the stipe is from one to two inches 

 long, and the frond from two to four inches long, by 

 half an inch to an inch broad. 



S. ciliatum is very widely distributed throughout 

 the tropical regions of both hemispheres, and has 

 lately been foimd in New Zealand ; it is a free- 

 growing, handsome species, with fringed and 

 winged stipes, one or two inches long, and oblong- 

 acuminate, tripinnatifid fronds, two to six inches 

 long, and one to two inches broad at the centre ; a 

 magnificent variety of this, spUndidum, which occurs 

 in Guatemala, Ecuador, and west tropical Africa, 

 has fronds a foot in length. 



S. demissum is one of the most beautiful species 

 of the genus, as well as one of the easiest to manage ; 

 the firm, erect, wingless stipes are from four to six 



inches long, and the finely cut ovate-triangular 

 fronds, which are light green when young and a 

 very dark glossy green when mature, measure from 

 four to twelve inches or more in length, by three or 

 four inches in breadth. It is a native of New 

 Zealand, Fiji, Java, the Philippines, and adjacent 

 Polynesian Islands. 



S. flahellatum, from Australia, New Zealand, and 

 Lord Auckland Isles, is a near ally of the last- 

 named. It has glistening, glossy green, ovate- 

 pointed, thrice-cut fronds, from four to twelve 

 inches long, by two to four inches broad. 



S. fuciforme is a strikingly distinct species, from 

 South Chili and Juan Fernandez. It has strong, 

 erect stipes, four to eight inches long, narrowly 

 winged above; and beautiful, bluish-green, wavy, 

 triangular lance-shaped, thi'ice-cut fronds, one to 

 two feet in length, by four to six inches in breadth. 



S. hirautum, a native of tropical America and 

 Madagascar, &c., has once-cut, hairy, linear-oblong 

 fronds, two to six inches long, by half an inch 

 broad. It forms a dense, compact carpet of delicate 

 fronds, of a peculiar brownish-green hue. 



S. lineare has flaccid, pendulous, long, narrow 

 fronds, and forms densely interlaced masses on rocks 

 and trees. It is a native of tropical America, from 

 Jamaica and Mexico, southward to Brazil and 

 Peru, ascending on the Andes of Ecuador to 12,000 

 feet, and also occurs in the Mauritius. 



H. polyanthemos has slender, wingless stipes, two 

 or three inches long, and thrice-cut, ovate-oblong, 

 smooth, dark green fronds two to eight inches long, 

 by one to three inches broad. It is found every- 

 where throughout the tropics. 



S. pulcherrimum is a very handsome New Zea- 

 land species, with ample, finely-cut, firm, bright 

 green, glossy fronds, ovate-triangular in outline, 

 and measuring from six to twelve inches or more in 

 length, by four to six inches in breadth. 



S. iunbridgense, once abundant at Tunbridge 

 Wells, is widely distributed throughout the British 

 Islands; the extra-British distribution is Belgium, 

 France, Germany, Italy, Canaries, and south tem- 

 perate regions. It has an ovate frond, pinnate 

 below and pinnatifid above, with spreading spinulose- 

 serrate pinnae, and toothed involucre. 



The other British species, H. unilaterale, has more 

 rigid, darker green fronds, which are oblong in out- 

 line, pinnate below or throughout, with decurved 

 spinulose-serrate pinnules, and entire involucre. It 

 occupies about the same geographical area as the 

 last-named. 



Cultivation. — Undoubtedly the essential require- 

 ments of filmy ferns are a fair amount of light with 

 continuous and absolute protection from every ray 

 of direct sunshine, and an atmosphere constantly at 



