THE SPLEENWORT FERNS 91 



looks dead and withered. When moistened, however, the leaf 

 expands and again presents its green upper side to the light. 

 This fern grows on walls and ruins, up to about six hundred feet 

 above sea-level, usually on the south side of the wall. The stem 

 is short, stout, scaly, and tufted, the leaf-stalk blackish and 

 scaly, and the frond 4 to 6 inches long and leathery, the lobes 

 about half an inch long. The spore-masses are in lines, hidden by 

 the scales on the under side of the lobes, and the protecting scale 

 is small or absent being rendered unnecessary by the abundant 

 small scales which cover the lobe below. 



The Maiden-hair Spleenwort (A. Trichomanes), on walls and 

 rocks up to 2000 feet, has a crowded rosette of rigid narrow leaves, 

 about six inches long, arising from the short stout creeping stem. 

 The frond consists of paired dark-green rounded or oblong leaflets, 

 with a wiry black stalk representing about half the length of the 

 whole leaf. The leaflets are evergreen ; when they fall off they 

 leave the black stalks bare. This fern is not very easy to grow ; 

 it does best in a mixture of porous loamy soil, bits of sandstone, 

 and lime from old walls, and the soil must be well drained, since 

 the plant cannot endure excess of moisture. 



The little Wall Rue (A. Ruta-muraria) has a short scaleless 

 stem, and grows chiefly on the northern side of walls, mounting 

 up the wall as high as possible. In dry situations it dwells alone, 

 but in moister parts has for companions the maiden-hair and scaly 

 spleenworts. It is a difficult fern to cultivate, requiring a very 

 stony soil and a dry atmosphere. The leaf is very variable in 

 length, being over 6 inches long in sheltered positions, but reduced 

 to an inch in high exposed places, and equally so in amount of 

 lobing. The leaf-stalk is purple, and the leaflets are usually 

 divided into two or three fan-shaped stalked segments. The spore- 

 masses are in lines at first, but later form broad patches. 



The Black Spleenwort (A. Adiantum-nigrum) resembles wall 

 rue in general habit, but the leaf is larger and more divided, deep 

 shining green above and paler below ; the ultimate leaflets are 

 notched and toothed. It is usually very difficult to remove this 

 fern from a wall, for its stem is deeply embedded in the crevices. 

 The leaf is often nearly a foot long, and has a rather long stalk 

 which passes out through the wall crevice, so that the weight of 



