GLEICHENIA. 



213 



section, similar to that noted in Eugleichenia^ the Mertensias are, even to the 

 superficial observer, totally distinct. Their stipe (stalk) is forked, branched, 

 and copiously bipinnate (twice divided to the midrib) or, from the develop- 

 ment of an axillary bud, proliferous and pinnate ; the very long leaflets are 

 again pinnate, and frequently their pinnules (leafits) are deeply pinnatifid. 

 The spore masses, stalkless as in the plants of the foregoing section, and 

 disjDosed three or four together, are situated near the middle, or at the 

 forking, of the veinlets, the ultimate leaflets being comb-like and furnished 

 with linear (long and narrow) or oblong segments much longer than in the 

 plants of the preceding section, 



Mthough the genus Gleichenia has no British representatives, it shows 

 a very extensive geographical distribution. Some of its members are native 

 of New Zealand, New South Wales, and Tasmania ; others are of West 

 Indian and South American origin ; while China and Japan, and even South 

 Africa, produce a few distinct species. 



Culture. 



The principal requirements of these singular and beautiful Ferns have 

 already been given at pp. 64 and 65 of Vol. I. ; but it is as well, perhaps, 

 to repeat here that in the majority of cases cool treatment is the most 

 suitable for them, and that with very few exceptions they fare best in 

 a house where during the wdnter the temperature falls as low as 45deg. In 

 fact, most, if not all, of the failures experienced in the early attempts at culti- 

 vating these charming plants may be traced to the pernicious practice of 

 growing them in too much heat — treatment which caused them to make 

 stunted growths, generally full of thrips and scale. Besides the house being 

 at most what is usually called intermediate, it should also be light and well 

 ventilated. Bright hght is indispensable in the culture of Gleichenias ; they 

 will even withstand a little sunshine during the morning and the afternoon, 

 and be benefited by it. Light, in fact, is of such importance that if a plant 

 in perfect health be placed under, say, Tree Ferns, or under any other plant 

 that will permanently shade it, it will soon start on a retrograde march, and 

 show by its spindly growth that it does not at all appreciate the presence 

 of neighbours taller than itself. It is also worthy of note that success 



