THE EUROPEAN BRISTLE FERN. 291 
TRICHOMANES SPECIOSUM, v. ANDREWSII, Newman, Hist. Brit. Ferns, 2 ed. 315. 
TRICHOMANES ANDREWSI, Newman, Hist. Brit. Ferns, 2 ed. 14. 
TRICHOMANES BREVISETUM, B. ANDREWSII, Henfrey, Francis Anal. Brit. Ferns, 
5 ed. 67. 
Caudex black, creeping, elongated, tomentose, covered with small 
thick-set articulated dark-coloured jointed hairs. Fibres black, stout, 
branched, densely tomentose. 
Vernation circinate. 
Stipes variable in length, from one-fourth to one-half the entire 
length of the frond, terete, margined above with a narrow mem- 
branaceous wing, which is sometimes continued nearly to the base, 
where it is clothed with articulated hairs; lateral, adherent to the 
rhizome. Rachis everywhere margined with a narrow membran- 
aceous wing. 
Fronds six to twelve inches or more in length, pellucid-membran- 
aceous, dark olive-green becoming darker when dry, quite smooth, 
ovate-lanceolate or triangular-ovate, more or less attenuated at the 
apex, tripinnatifid or quadripinnatifid. Primary divisions (pinne- 
like segments) ovate-lanceolate ; secondary ones ovate, obtuse, cune- 
ate at the base; tertiary ones oblique oblong ; the ultimate lobes or 
segments oblong, toothed, the teeth short, linear, entire emarginate 
or bifid. In highly developed fronds of the triangular form the 
secondary divisions are often longer and comparatively narrower, 
and the ultimate divisions are more distant. The teeth at the apex 
of each series of divisions are frequently more elongated. 
Venation consisting of a series of forked ramifications (veins) of the 
wiry ribs which issue alternately from the main rachis and enter 
the primary divisions; these are everywhere bordered with a pellucid 
wing of the same loosely cellular texture as the frond itself. The 
lowest anterior branch of these veins (veinlet) in the ultimate seg- 
ments is, in the fertile fronds, continued beyond the margin, and 
forms the receptacle ; but in the barren ius the apices of the 
veinlets do not quite reach the margin. 
Fructification scattered over the fronds, extra-marginal, /. e. the 
tubular involucres are projected outwards from the margin, the 
opening being exterior. Sori consisting of sessile spore-cases, 
v2 : 

