-14 
FERNS. 
[Aspidium. 
Hab. — This is one of the rarest Ferns, not only here but on the Continent. 
The only recorded habitats of it in this country, were the Lows, in Holt Heath, 
Norfolk, Rev. R. B. Francis. On bogs among alder bushes, at Westleton, 
Suffolk, Mr. Davy. Oxton Bogs, Notts, Dr. Hoiuitt and Mr. T. Cooper. But 
it has been lately discovered in various other parts of Suffolk and Norfolk, and 
also in Staffordshire and Cheshire. One of these habitats may, perhaps, be now 
expunged, as Mr. Domes informs me it is thirty years since it was last found at 
the Lows in Holt Heath. It was stated on page 7 0, of the first edition, that I 
had reason to believe that this plant grew on Wimbledon Common ; this was 
an error of judgment or of memory in my informant. It does not grow there, 
but the A. spinulosum does. Mr. Mackay admits it into the Irish Flora, as growing 
in the grounds of Viscount Gough, at Rathronan, near Clonmel, found there by 
Mr. G. S. Gough, in 1835 ; he says that the Irish plant is acutely serrate. 
Geo. — Oldenburgli, Bremen, Mecklenburgli, Hanover, and other parts of 
Germany. New York to Virginia. 
8.— ASPIDIUM RIGIDUM. 
RIGID SHIELD-FERN. 
(Plate III, fig. 5.) 
Cha. — Leaf lanceolate, bipinnate. Pinnae alternate. Pinnules 
narrow, oblong, obtuse, slightly pinnatifid. Segments broad, with 
2 to 5 (mostly 3) teeth, without bristles. Leaf-stalk scaly. 
Syn. — Aspidium rigidum, / look, in Bri. Flo., ed. 3 and 4, Swz. , Schk . — 
Aspidium spinulosum, Hook, in Bri. Flo., ed. 1. — Polypodium rigidum, 
Hoffm. — Polystichum rigidum, Decan. — Polysticlium strigosum, Roth . — 
Lastaea rigida, Presl, Newm. — Lophodium rigidum, Newm. 1854. 
Fio. — E.B. Sapp. 2724. — Schk.Jil. t. 38. — Newm. page 175 (1854), Moore, 112 
(1853). 
Des. — Rootstock tufted. Leaf-stalk thick, rigid, very scaly all 
the way up. Leaf lanceolate, not contracted below, erect, from one 
to two feet higlit. Pinnae tapering, alternate, very close together, 
from thirty to forty pairs, their stalks very much thickened at their 
union with the main stalk. Pinnules distinct, decurrent, oblong, 
blunt, slightly pinnatifid, with the segments obtuse, mostly tri- 
dentate, but not spinulose, their midrib waved. Sori large and 
abundant, chiefly on the upper part of the frond. Indusium round, 
reniform, persistent, with a glandular margin, white at first, lead- 
coloured afterwards, covering the whole mass of thecae, &c. 
Much diversity of opinion has existed respecting the identity of this very distinct 
plant, a small state of the spinulosum being very 7 often sent for it. Its generally 
alternate pinnae would be perhaps sufficient to distinguish the two, but in other 
respects it differs essentially from that more common species. The leaf-stalk of 
the rigidum is very scaly and very much thicker than in the spinulosum, its 
pinna; much more numerous and nearer together, the lower pair not broader 
than the rest, the pinnules of all quite decurrent, and not by any means spinulose, 
besides which theindusia 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 
