378 



THE BOOK OF CHOICE FERNS. 



River Country Cliffs. It was found in every instance on the under-side of 

 an overhanging rock, generally considerably withdrawn from the light, never 

 reached by the direct rays of the sun. It does best on a moist rock, where 

 it is bedewed by spray from falling water or where the clear, trickling water 

 keeps the fronds constantly moist. Each frond of this Fern has an interesting 

 history ; from first to last they live many years. The whole under-surface 

 of the rock is one matted mass of roots and stems, covered with innumerable 

 translucent fronds in all stages of growth and maturity. The young frond 

 gradually expands and slowly attains full size. In two or three years perhaps 

 the fruit begins to develop on the edges of the fronds, at the tips of the 

 veins. This fruit is clustered in a cup around a fine hair which comes from 

 its centre. The hair, or bristle, continues to grow in length, and the fruit to 

 develop at its base around it. As the bristle grows in length — sometimes 

 it is found lin. long — the ripe fruit is shed, so that there remains about the 

 same quantity of fruit always at the base of the hair. The whole life of the 

 frond may be half-a-dozen years." The dimensions of the fronds, given as 



from 3in. to 7in. long and less, sometimes 

 much less, than 2in. broad, as well as their 

 being produced from a creeping rhizome 1ft. 

 long, but less than a line thick, and their 

 being borne on short stalks winged from the 

 very base to the top of the fronds, unmistak- 

 ably point out that this is the T. alabamense 

 of gardens. 



T. r. Andrewsii — An-drew'-si-i (Andrews'), 

 Newman. 



This variety, found in 1842 at Iveragh, 

 Ireland, by Mr. Wm. Andrews, of Dublin, is 

 very distinct. It differs from the species in 

 having narrower, more spear-shaped fronds, in their leaflets being more distant 

 and distinct (Fig. 106), in the stalk being more elongated and less winged, 

 and in the involucre being quite sunk in the margin of the frond. — Lowe, Our 

 Native Ferns, ii., fig. 859 ; Ferns British and Exotic, viii., p. 43. Moore, 

 Nature-printed British Ferns, t. 48c. 



Fig. 106. Portion of Frond of Trichomanes 

 radicans Andrewsii 



(i nat. size). 



