26 
THE BEECH FERN. 
The pinnae (or leaflets) have an acutely lance- shaped 
outline and are deeply pinnatifid, usually standing in 
pairs, opposite to each other, the lowest pair drooping 
toward the root and set on at a short distance from 
the rest. The united bases of the pairs of the other 
pinnae — when they happen to stand exactly opposite 
to each other — exhibit more or less distinctly a cruci- 
form figure, by which, regard being had also to the 
general triangular outline and sub-pinnate division, 
this species may be known from the other Polypodies. 
The venation consists of a slender flexuous midvein 
(or rib), from which proceed alternate or sometimes 
opposite veins extending to the margins of the lobes 
or lobules, — either simple or once forked at about 
half their length. The veins when simple, or the 
anterior venules when divided, bear a sorus at a short 
distance from the edge of the lobule. This almost 
marginal fructification extends nearly over the whole 
frond, the sori being small and circular, arranged in 
series, and often becoming confluent in lines. When 
the fructification is but partially developed only one 
or two of the lowermost veins are fertile, in which 
case the marginal series of sori is not very manifest. 
The spore-cases are small, numerous, and of a pale 
brown hue ; the spores ovate and smooth. The fronds 
in this species become lateral and distant from each 
other on the underground stem, in consequence of its 
rapid elongation ; and they are adherent, that is to 
say, the stipes is not furnished with a natural point 
of spontaneous separation. 
For cultivation in pots or cases it requires good 
