106 THE BOOK OF CHOICE FERNS. 



covered, but it may also be due to the intense golden colour of the under- side 

 of its fertile fronds, which is produced by the presence of the enormous 

 quantity of spore masses, disposed irregularly in one, two, or three series, 

 and from which, when ripe, a most profuse, fine, bright yellow powder escapes 

 and covers the upper surface of the fronds that are beneath them. — Hooker., 

 Species Filicum, v., p. 16. Nicholson, Dictionary of Gardening, iii., p. 187. 

 Lowe, Ferns British and Exotic, ii., t. 5. Eaton, Ferns of North America, 

 i.., t. 16. 



There are in commerce and extensively grown three plants so closely 

 related to P. aureum that, although usually considered in gardens as distinct 

 species, the authors of " Synopsis Filicum " acknowledge them only as 

 varieties. These are : 



P. a. areolatum — ar-e-ol-a'-tum (areolate), Humholdt, Bonpland, and 

 Kunth. 

 A very interesting plant, native of South America and Mexico, with 

 fronds smaller and of a more leathery texture than those of the species, 

 and deeply pinnatifid ; their leaflets, narrowly spear-shaped, somewhat sharp- 

 pointed, and with moderately refiexed edges, being cut nearly to the midrib. 

 The fronds, Ift. to 2ft. long, are glaucous underneath, and the sori (spore 

 masses) are disposed in a single row. — Hooker, Synopsis Filicum, p. 347. 

 Nicholson, Dictionary of Gardening, iii., p. 187. Lowe, Ferns British and 

 Exotic, ii., t. 12. 



P. a. pulYinatum — pul-vi-na'-tum (cushion-like), Link. 



This variety, native of Brazil, was, according to Lowe, introduced into the 

 Eoyal Gardens, Kew, in the year 1841. Its fronds, which are of about 

 the same dimensions as those of the species, are deeply pinnatifid, their leaflets 

 being less wavy but more deeply cut towards the midrib ; they, however, lack 

 the beautiful colour of those of the species, being pale green and hardly at all 

 glaucous. P. a. pidvinatum is nevertheless a distinct and pretty plant, the 

 most attractive part of it being undoubtedly the under-surface of its fronds, 

 which is copiously furnished with beautiful orange-yellow sori (spore masses). 

 — Hooker, Synopsis Filicum, p. 347. Nicholson, Dictionary of Gardening, iii., 

 p. 187. Lowe, Ferns British and Exotic, ii., t. 56. 



