FERN TRIBE 107 
Sub-Order I. PouyPopraceé. 
* Capsules with a vertical elastic marginal ring, which bursts irregularly. 
1. Potypopy (Polypédiwm).—Capsules seated on the back of the frond in 
circular clusters, without an indusium ; veins in the British species, simple or 
forked. Name from the Greek polus, many’; and pous, a foot ; either from 
the shape of the frond, or from the branching rootstocks of some species. 
2. GYMNOGRAM (Gymnogrémme).—Capsules seated on the back of the frond, 
in linear clusters, without an indusium ; veins in the British species, simple or 
forked. Name from the Greek gymnos, naked ; and gramme, a line or letter, 
from the fancied resemblance of the forked veins to alphabetical letters. 
3. ROCK-BRAKE . (Allosérus).—Capsules on the back of the frond, the 
edges of its lobes rolling under, and forming an indusium. Fronds of two 
forms ; the barren frond leaf-like; the fertile contracted, and bearing the 
fructification at its margin. Name from the Greek allos, various, and _soros, 
amass. Also known as Cryptogramme. 
4, Woops!A (Woddsia).—Capsules at the back of the frond, covered by a 
roundish or kidney-shaped indusium, attached beneath the clusters, and cut 
at the edges into many thread-like segments. Name in memory of Joseph 
Woods, author of ‘The Tourist’s Flora,” etc. 
5. Buckner FERN (Lastréa).—Clusters at the back of the frond, nearly 
circular, covered by a kidney-shaped indusium, attached at the notched side ; 
veins distinct after leaving the mid-rib, not uniting with the adjoining lobe. 
Name from M. De Lastre, of Chatellerault. Generally known as Nephrodium, 
but the British species are all members of the sub-genus Lastrea. 
6. SHIELD FERN (Poljstichum).—Clusters seated at the back of the frond, 
covered by a circular indusium, attached at its centre. Name from the 
Greek polus, many ; and stichos, a row ; from the regular lines formed by the 
clusters of fructification. This is a sub-genus of the genus Aspidium. 
7. BuaDDER FERN (Cystépteris).—Clusters of fructification roundish ; 
indusium hooded, and attached by its broad base. Name from the Greek 
kystos, a bladder ; and pileris, a fern, in allusion to its hollow indusium. 
8. SPLEENWoRT (Aspléniwm).—Clusters at the back of the frond, oblong 
or linear, attached along the upper or inner side of the veins; indusium 
opening towards the mid-vein, or inwardly. Name from the Greek asplenon, 
given by the ancients to some fern which they believed to affect the spleen. 
9. LaDy FERN (4 thyrium).—Clusters at the back of the frond, covered with 
a kidney-shaped or crescent-shaped indusium, attached along the upper side 
of the lateral veins, opening towards the mid-vein, its margin fringed with 
slender hair-like segments. Name from the Greek athyros, open ; because the 
indusium stands out separated from the frond, and is at length turned back 
open from it. This is a sub-genus of Aspleniwm. 
10. ScALy SPLEENWORT (Céterach).—Clusters of capsules at the back of the 
frond, placed on netted veins, and lying among thick masses of dark brown 
chaffy scales, which cover the whole back of the frond ; indusium obsolete. 
Name supposed to be the C%etherak of the. Arabian physicians. This is a 
sub-genus of Aspleniwm. 
14—2 
