Aspidium.] 
FERNS. 
33 
less numerous, and their covers persistent, not hidden by the capsules. It 
very nearly resembles the American Aspidium goldianum. 
Hab. — This is one of the rarest Ferns, not only here but on the Continent. 
The only recorded habitats of it in this country are the Lows in Holt-heath, 
Norfolk, Rev. R. B. Francis ; on bogs among alder bushes, at Westleton, 
Suffolk, Mr. Davy; Coxton Bogs Notts, Dr. Howitt and Mr. T. Cooper. Mr. 
Mackay admits it into the Irish Flora, as growing in the grounds of Sir H. 
Gough, at Rathronan, near Clonmel, found there by Mr. G. S. Gough, in 1835 ; 
he says that the Irish plant is acutely serrate. 
Geo. — Oldenburgh, Bremen, Mecklenburg, Hanover, and other parts of 
Germany, New York to Virginia. 
9.— ASPIDIUM BIGIDUM. 
RIGID SHIELD FERN. 
(Plate 2, fig. 10.) 
Cha. — F rond bipinnate. PinntE alternate. Lobes oblong, de- 
current, doubly toothed. Bachis scaly. 
Syn. — Aspidium rigidum Hook, in Bri. Flo., eel. 3., Swz., Schk. — Aspidium 
spinulosum, Hook, in Bri. Flo., ed. 1. — Polypodium rigidum, Hoffrn , — 
Polystichum rigidum, Decan. — Polystichum strigosum, Roth. 
Fig. — E. B. sapp. 2724. — Schk. fil. t. 38. 
Des. — Boot tufted. Bachis thick, rigid, very scaly all the way 
up. Frond lanceolate, not contracted below, dark green, erect, 
from one to two feet high. Pinnae tapering, alternate, very close 
together, from 30 to 40 pairs, their stipes very much thickened at 
their union with the rachis. Lobes distinct, decurrent, oblong, 
blunt, doubly toothed, but not spinulose, their midrib waved. Sori 
large and abundant, chiefly on the upper part of the frond. Inclu- 
sium round-reniform, persistent, white at first, lead-coloured after- 
wards, covering the whole mass of capsules. 
Much diversity of opinion has existed respecting the identity of this very 
distinct plant, a small state of the Spinulosum being very often sent for it. Its 
alternate pinnae would be amply sufficient to distinguish the two, but in other 
respects it is essentially different from that more common species. The rachis 
of the Rigidum is very scaly and very much thicker than in the Spinulosum, 
its pinnae much more numerous and nearer together, the lower pair not broader 
than the rest, the lobes of all quite decurrent, and not by any means spinu- 
lose, besides which the indusia are very large, and so different, as at once 
to distinguish the two plants ; in addition to which it may be remarked, that 
Aspidium rigidum is much darker in color than the spinulosum, as it is also 
than the cristatum. It is intermediate between the last and next species in 
the number of its divisions, but does not resemble either of them in habit or 
appearance. 
Hab.— Found by Rev. W. Bree, in 1815, on Inglcborougli, near the foot of 
the mountain, towards the neighbouring village. 
Geo.— Switzerland, Prussia, Germany, &c. 
