THE SPLEEN WORT. 59 
var. assimile: pinne elongate linear-oblong, truncate-auricled, narrowed 
upwards, with large, distant, toothed lobes. 
var. sub-bipinnatum : pinne sub-pinnate at the base, pinnatifid throughout, 
with elongate serrated lobes. 
+t Rachis not winged. 
t Rachis ebeneous throughout, blumtly keeled behind. 
5. A. Trichomanes: fronds pinnate, herbaceous; pinne small, oblong, de- 
ciduous, entire or crenate, obliquely cuneate at the base, attached by the 
lower angle. 
(a) Fronds normal. 
var. incisum: pinne deeply pinnatifid, the segments inciso-serrate. 
var. subequale: pinne oblong, crenated or sinuate, nearly equal. sided, 
attached at or near the centre of their base. 
(b) Fronds abnormal or monstrous. 
var. cristatum: fronds symmetrically multifid-crisped at the apex; rachis 
undivided below. 
var. multifidum: rachis bi-tri-chotomously divided below, the apices of 
the branches multifid-crisped. 
var. ramosum: rachis bi-tri-chotomously divided below, the branches flat 
and tapering to the point. 
tt Rachis green above, compressed. 
6. A. viride: fronds pinnate, herbaceous ; pinn® roundish-ovate or rhomboidal, 
crenated, stalked, persistent. 
$ Acropteris.—Sori linear, usually elongate ; veins (in the British 
species) flabellately-forked, without a costa. 
* Fronds bipinnate. 
7. A, Ruta-muraria: fronds deltoid; pinnules obovate or cuneate-rhomboidal, 
the anterior margin equally toothed ; indusium crenulate. 
var. cuneatum: pinnules wedge-shaped, the larger ones three-lobed. 
var. cristatum: apex of the fronds and pinne dilated and crisped. 
** Fronds pinnate. 
8. A. germanicum: fronds linear (rarely bipinnately divided) ; pinne alternate 
narrow oblong wedge-shaped, unequally toothed at the apex; indusium 
entire. 
*** Fronds rachiform, pinnatifidly cleft. 
9. A. septentrionale: fronds simple or divided into 2-3 rachiform segments, 
which have distant linear marginal teeth ; indusium entire. 

