O NO CLE A. 15 



towards the summit. These barren fronds sometimes reach l^ft. in length, 

 especially when the plants are well established in a naturally and constantly 

 moist part of the rockery, and, as they are borne on stalks of about the same 

 length, they attain about 3ft. in height, a result never attained under pot- 

 culture. The texture is herbaceous (soft and papery), the surfaces are perfectly 

 smooth, and the under- side is slightly bluish. The fronds do not last long 

 when cut, even when put in water, but shrivel almost immediately, showing 

 a disposition to fold their leaflets face to face, for which reason, Eaton says, 

 the plant has received the popular name of " Sensitive Fern." The fohage of 

 this Fern is also very sensitive to a cold temperature, for the first autumn 

 frosts always destroy it, and the late spring frosts which we sometimes 

 experience in May and June have the same injurious effects. These remarks 

 apply to barren fronds only, which are by far the handsomer and the more 

 numerous. Fertile fronds are not very common, and are so unlike the barren 

 ones that no one unacquainted with the plant would suppose them to be 

 related to each other. Both kinds are produced from a thick, fleshy rhizome 

 which runs underground ; the fertile ones stand about half the height of 

 the barren ones, and are perfectly rigid and nearly black when fully 

 developed. Another peculiarity is that they dry up in winter, but remain erect 

 during the following summer, so that a fruiting plant often bears fertile fronds 

 of two years' growth. The involucre with which the sori (spore masses) are 

 covered is globose, and bursts at the summit. — Hooker^ Species Filicum, iv., 

 p. 160. Nicholson, Dictionary of Gardening, ii., p. 497. Lowe, Ferns British 

 and Exotic, vi., t. 1. Eaton, Ferns of North America, ii., t. 72. 



O. S. obtusilobata — ob-tu-sil-ob-a'-ta (having blunt lobes), Schkuhr. 



A rare, abnormal form, in which the leaflets of some of the barren fronds 

 become again pinnatifid and more or less contracted, but when grown side by 

 side with the species this variety frequently resumes its normal characters. — 

 Nicholson, Dictionary of Gardening, ii., p. 497. Lowe, Ferns British and 

 Exotic, vi., p. 7. Eat07i, Ferns of North America, ii., p. 199. 



