smith’s fern. 
135 
from P. Dryopteris, the form of the un expanded fronds being 
characteristic of that species only. 
The roots are fibrous, and in all respects resemble those of 
P. Dryopteris : the rhizoma, described as the root by Smith, in 
the passage previously cited, is dark brown, creeping, and some- 
what stouter than in P. Dryopteris. The fronds make their ap- 
pearance in May, and their habit and mode of unfolding differs 
from that of P. Dryopteris ; the three 
portions of the frond never assume the 
appearance of three little balls, which 
I have noticed as an excellent diag- 
nostic of P. Dryopteris^ but all the 
pinnules appear somewhat globular, 
the first pair of pinnae differing from 
the second in little else than magnitude. 
I have taken great pains to give a faith- 
ful representation of some young fronds : 
I divided the stem of each on account of 
its inconvenient length, and laying them 
on the block before me, made an accu- 
rate copy both as regards size and figure 
(p. 131). The stems are much stouter 
and more succulent than those of P. 
Dryopteris, and I think also more scaly; 
they are of the same dull green as the 
frond, whereas those of P. Dryopteris are frequently purple or 
blackish, and have a more wiry appearance. The frond attains 
its full development in July, and matures its seed in August. 
The form of the expanded frond is nearly triangular, the base 
being shorter than the sides, and altogether not unlike that of 
the common Brakes ; the pinnas are opposite, the first pair always 
have a short naked stem ; the second pair frequently have this, 
but not invariably ; and the naked stem of the first pair of pin- 
nae is always much shorter and more slender than the main stem 
between the first and second pair, whereas in P. Dryopteris 
these three stems are of nearly equal length and thickness ; the 
pinnae are pinnate, the pinnules deeply pinnatifid ; all parts of 
the frond are covered with the mealy pubescence described by 
