TRICHOMANES. 



359 



(2) Plants with fronds entire or slightly lobed, but provided with a 

 central midrib extending from the base to the summit. The North American 

 T. Petersii is perhaps the best illustration of the character of this section. 



(3) Plants with fronds entire below, palmate or digitate (hand -shaped or 

 fingered) above. The pretty little Japanese and Indian T. parvulum is an 

 excellent example of this section. 



(4) Plants with fronds more or less deeply cleft, but not truly pinnate, 

 and with the main rachis (stalk) distinctly winged throughout. T. alatum is 

 the best representative of this section. 



(5) Plants with fronds more or less deeply cleft, but not truly pinnate, 

 and with the main rachis hardly, if at all, winged in the lower part. The 

 most distinct illustration of the character of this section is found in the 

 "Killarney Fern," T. radicans. 



(6) Plants in which the main rachis is quite free or only very slightly 

 winged towards the summit, the fronds are simply pinnate, and their leaflets 

 are not divided. The characters of this section are well shown in T. pinnatum. 



(7) Plants in which the main rachis is quite free or only very slightly 

 winged towards the summit, the fronds are decompound (much-divided), 

 slender, and flaccid, and their ultimate segments are very narrowly linear or 

 filiform (thread-like). T. trichoideum well illustrates this section. 



(8) Plants with decompound fronds, borne on a main rachis of a rigid 

 nature, with their ultimate segments of a somewhat leathery texture, which 

 characters are w r ell shown in T. maximum. 



The genus Trichomanes is represented in Great Britain by a solitary plant, 

 T. radicans, and there are no other species known to be native of Europe. 



Culture. 



With the exception of a few species which undoubtedly require more than 

 greenhouse temperature, the Trichomanes may without danger be submitted to 

 the treatment recommended for Hymenophyllums (see Vol. II., p. 300). When 

 not otherwise stated in the descriptions of the species, they may be considered 

 as thriving under the cool treatment recommended for Filmy Ferns generally. 

 To the particulars which have already appeared in Vol. I. (pp. 73 to 81) 

 respecting the culture of Filmy Ferns we may add that, whereas we do not 



