FERNS. 



65 



these require shade and shelter from direct sunlight 

 and dry currents of air, and unlimited atmospheric 

 moisture. No ferns are more easily grown if the 

 necessary conditions obtain, and none make more 

 beautiful objects. A house with a north aspect 

 seems to suit them best ; at any rate, given such a 

 structure, they require far less attention than in the 

 ordinary green-house or conservatory. A mixture 

 of broken potsherds and sphagnum, with a little 

 fibrous peat, from which all the finer portions have 

 been removed by beating, suits them admirably ; 

 even this, however, is not necessary, as we have seen 



rienced no ill results. Nothing could exceed tha 

 beauty of a house full of the species just named in 

 one of the loading London nurseries, as we saw it 

 a year or two ago. The cemented floor had a 

 raised rim round the under side of the staging, 

 and this was kept constantly filled with water ; the 

 plants, too, were watered overhead daily during the 

 summer months. T, hymenophylloides, and the last- 

 named species too, thrive in the open air with but 

 little care and attention in many parts of England. 

 There are sheltered nooks in many an out-door 

 fernery where both would succeed well enough, with 



TODEA SUPEKBA, 



plants thriving without potting material of any 

 kind. Imported plants have been wedged into pots 

 — of course, attended to in the matter of moisture, 

 atmospheric and otherwise — and'^ in a short time 

 have clothed themselves with a mass of splendid 

 dark green plume-like fronds. Sometimes thrips 

 infest the delicate film-like fronds, and, unless these 

 are got rid of, the plants soon become unsightly. 

 The best way, and one which does not damage the 

 tender fronds in the slightest degree, is to submerge 

 the entire plants for, say, twelve hours or more in 

 water, the same temperature as that of the structure 

 in which they grow. 



We have seen T. superba growing splendidly in 

 absolutely unheated houses, where, during severe 

 winters, the plants have been literally coated with 

 ice for days at a time, and yet they have expe- 

 29 



a hand-glass or some similar contiivance to insure 

 constant atmospheric moisture. 



The Acrostiehums. — In the somewhat com- 

 prehensive sense in which the genus Acrostichum is 

 understood by the authors of the " Synopsis Filicum," 

 it contains above one hundred and seventy species, 

 and embraces no less than a dozen genera which, 

 by various other authorities, have been regarded as 

 distinct. Indeed, in the work just mentioned, 

 Acrostic/mm includes the whole group of polypodia- 

 ceous ferns belonging to the tribe Acrostichea;, with 

 the single excex)tion of that remarkable and in- 

 teresting genus, Platycerium, the various species of 

 which are generally known in gardens as Stag's- 

 horn Ferns. 



The Acrostiehums are widely distributed through- 



