•26 
FERNS. 
[ Woodsio. 
WOODSIA, Br. HAIR-FERN. 
(Named in honor of Mr. J. Woods, an English Botanist.) 
portion of a frond of Woodsia Ilvensis, natural size. B, ditto enlai yed. 
C, sorus longitudinally divided. D, indusium. E, one portion of ditto. F, 
scale. G, theca. H, spores. 
Mr. Brown first separated from the Polypodiums,8(c., this very distinct genus, 
which contains only two British and four foreign species, all very small plants, 
and natives of mountainous regions. The indusium, if such it can he called, is 
very singular and beautiful : it is attached under the mass of theca;— inclosing 
them at first in a bag, it then becomes split into numerous segments, which look 
like hairs interspersed with the theca, and were so considered until Mr. Brown 
showed their true nature in “ Trans. Linn. Soc.” vol. xi. 
WOODSIA ILVENSIS. 
OBLONG WOODSIA. HAIRY WOODSIA. DOWNY HAIR-FERN. 
(Plate 1, fig. 6, A.) 
Cha. — F rond pinnate, oblong, scaly. Pinnae oblong, blunt, 
deeply cut, crenate. 
Syn. — Woodsia Ilvensis, Brown, Smith, Hook., Spreng. — Polypodium Ilvense, 
Swz., Willd., Schk. — Acrostichum Ilvense, Linn., Huds., Ehrh . — 
Polypodium Arvonicum of With., in description but not in references.* 
Fig. — E. B. Supp. 2G1G.— Flo. Dan. 391 .—Pluk. Phyt. 281, fig. 4, (good.) 
Des. — Root perennial, tufted, black, smooth. Fronds numerous, 
1 to 4 inches high, covered with capillary, brownish-white scales. 
Rachis scaly ; the lower third of it without pinnae, the upper two- 
thirds containing six to eight pairs, placed nearly opposite to each 
other. Larger pinnae cut into from four to six blunt segments on 
each side. Sori scattered, convex, consisting of five or six roundish 
thecae. Cover torn into a few capillary divisions. 
Mr. Sowerby observes, that the capillary segments of the indusium are not 
so numerous as in the next species, and the thecae more spherical. The plant 
cultivated and formerly sold at the London nurseries, under the name of W oodsia 
Ilvensis, is Notholsena distans, a plant in every respect different from ours, which 
is much smaller, and less white and downy than that New Holland species. 
Sit. — On rocks in mountainous countries. 
Has. — Higher parts of the Tees, Mr. J. Hogg. Rocks, (near where Oxytropis 
campestris grows,) between Glen Dole and Glen Phee, in the Clova Mountains, 
* I cannot refer to Withering' s Polypodium Arvonicum and Ilvense with certainty, ns his 
description of these two plants is very obscuro and far from characteristic. 
