292 THE BRITISH FERNS. 
clustered around the base of the filiform receptacle, which is free 
within the involucre, with its apex more or less projected beyond it. 
ASTER D A ED 
Involuere cylindrical cup-shaped or urn-shaped, somewhat tapering 
below, open exteriorly, supra-axillary, that is, produced in the upper 
axils of the (ultimate) lobes, more or less sunk in the apex of one of 
the lobes or teeth, the mouth sometimes slightly spreading, or shortly 
two-lipped.. Spore-cases sessile, oblique, latero-vertically compressed, 
roundish or obovate. Spores irregularly roundish or oblong, some- 
times three-cornered, minutely papillose. 
Duration. The rhizome is perennial. The fronds are also per- 
sistent, enduring for many years if not injured; they are stated to 
be about three years arriving at maturity, full development being 
obtained in the second year, and fructification produced in the third, 
after which they often show symptoms of decay. The sterile fronds 
however retain their freshness for many years when placed under 
SSE men menu 
ee 
congenial conditions. 
The pellueid much divided, yet not pinnated fronds of this species, 
produced from a creeping caudex, the extra-marginal urn-shaped or 
tubular involucres, the columnar filiform receptacle, and the oblique 
ring which girts the obliquely compressed sessile spore-cases, serve 
together to distinguish this plant from all other British Ferns. 
There are at least three forms or states of it met with in Ireland. 
One of these is the var. Andrewsii noticed below. Another with 
the fronds ovate-lanceolate, and the segments broader, most nearly 
accords with T. radicans of Swartz, as illustrated by Hedwig ; while 
a third, more triangular in outline, with the segments apparently 
narrower, seems to represent the T. speciosum of Willdenow. 
The Trichomanes 1s not now found in England, though it formerly 
grew in Yorkshire, in a small dark cavern, under a dripping rock a 
little below the spring of Elm Cragg Well, in Bellbank, scarce half 
a mile from Bingley. “Here, in 1758," Bolton writes, “I saw it in 
plenty,” but some alterations were made, the cavern was destroyed, 
and the plant perished. In 1782, however, being then engaged in 
publishing his.work on British Ferns, he was again fortunate in 
finding it in the same neighbourhood: “after several researches in 

