







THE BRITISH FERNS. 
Vernation circinate. 
Stipes short, usually about a third the length of the frond, some- 
times longer, dark chestnut-coloured below, the dark colour extend- 
ing more or less along the back of the rachis, sparingly scaly; 
terminal and adherent to the caudex. Rachis flat, with slight 
elevated margins in front, rounded behind, furnished sparingly with 
slender jointed hair-seales; partial rachides winged, and furnished 
with similar hair-scales. 
Fronds from three or four inches to a foot, or occasionally eighteen 
inches in length, rigid, bright green, “erectish, smooth except on 
the rachides, lanceolate, bipinnate. Pinne broadest at the base, 
narrowing to the point, usually horizontal, sometimes deflexed, 
scarcely more than half an inch in the smaller, two inches long in 
the larger fronds, all even the lowest scarcely stalked, sub-opposite 
or alternate; the lower more distant and somewhat shorter. Pin- 
nules obovate, obliquely-ovate, or dimidiately sub-quadrate, the 
anterior side being most developed, always more or less cuneate at 
the base. In the larger fronds the pinnules are pinnatifid below, 
with obovate sharply-toothed lobes, and coarsely toothed above, the 
teeth being mucronate; whilst in the smaller fronds the lobes are 
scarcely developed, the margin being coarsely mucronately-toothed. 
Occasionally the lower pinne are longer; sometimes the fronds are 
narrow and only pinnate with lobed pinn®; and in other instances 
they are membranaceous. 
Venation of the pinnules consisting of a flexuous costa or midvein, 
alternately branched, the lowest anterior vein directed to the prin- 
cipal lobe, and developing as many venules as there are marginal 
teeth, one venule extending into each tooth, but not quite reaching 
the margin ; the other veins are forked or simple, and correspond in 
number with the teeth. The termination of the veins is marked 
on the upper side of the fronds, by a depression of the surface. 
Fructification on the back of the frond and scattered over the 
whole surface. Sori indusiate, oblong, produced along the anterior 
sides of the venules, that is, above the fork of the veins, occupying 
rather the centre of the lobes than the centre of the pinnules, and 
therefore, sub-marginal in appearance; at first distinct, but becom- 
ing confluent in irregular masses on the lobes, and sometimes so 

