602 



THE BOOK OF CHOICE FERNS. 



India, &c. They are easily recognised by their sori (spore masses) being 

 marginal, oblong or roundish at first, but soon becoming confluent into 

 a continuous, marginal line, and by the total absence of involucre (covering 

 of spore masses), although the frequently inflexed nature of the edge of their 

 fronds gives them an appearance of being involucrate. There are no British 

 representatives. 



Culture. 



Some of the members of this genus require stove temperature all the 

 year round, while others succeed best under greenhouse treatment. In that 

 respect they are hke Gymnogrammes and Cheilanthes, which, on account of 

 either the woolly or the golden or silvery nature of the under- side of their 

 foliage, they also resemble in general appearance. It is not even unusual to 

 find on the same plant fronds the under -sides of which are adorned with quite 

 different colours — white, creamy, pale or deep yellow. In a Natal species the 

 under-side is wholly covered with a pinkish- coloured meal, but, unfortunately, 

 up to the present time this singular and interesting plant is only known 

 through dried specimens (Eaton, " Ferns of ISTorth America," i., p. 67). A 

 few of them, through their slender, ebony-back, shining stalks and small 

 pinnules (leafits), have much the appearance of certain Adiantums ; and one 

 often finds that inquiries respecting Gold and Silver Maidenhairs, although 

 such things exist, usually apply to N. flavens and N. nivea. 



Most of the plants belonging to this genus are of a somewhat delicate 

 nature, requiring more than usual care, especially during the winter, to 

 preserve their foliage, which, from its constitution, in many cases possesses 

 the property of retaining moisture and is therefore apt to decay. An important 

 fact to notice is that, from whatever part of the globe they come, all the 

 Nothochleenas are invariably found on rocks much exposed to the sun, but so 

 situated that the plants get a good supply of moisture at the roots. The 

 majority of the species are of erect or semi-erect habit, although a few 

 are particularly well adapted for growing in baskets of small or medium 

 dimensions, in which they display their elegant fronds to advantage. In any 

 case they should not be kept in a close or moist place, a somewhat airy 

 situation being indispensable to all of them. If grown in pots, a mixture of 



