THE MOUNTAIN POLYPODY. 71 
few lanceolate acuminate pale-brown deciduous scales, and on the 
upper part with a few scattered subulate ones, clothed along the 
whole length with minute reversed hairs; distant and lateral on the 
caudex. 
Fronds from four to eighteen or twenty inches in length, including 
the stipes, adherent to the rhizome, membranaceo-herbaceous, of 
a dull pale-green, hairy, ovate-triangular, much acuminate, pin- 
nate below, the apical portion pinnatifid. Pinne deeply pinnatifid, 
linear-acuminate, nearly or quite opposite; the lower pair lanceo- 
late, deflexed, distant from the upper, sessile, but attached only by 
their rachis; upper pinns sessile and broadly attached, and, except 
occasionally the second pair, confluent, so that the two basal lobules 
of the bases of the opposite pairs, unite to form a cruciform figure. 
The upper pinne have their points directed towards the apex of the 
frond, and their decurrent bases are continuous along the rachis. | 
Lobules oblong-obtuse, entire, or slightly crenato-dentate, directed 
towards the apex of the pinne. 
Venation of the lobules consisting of a slender flexuous midvein, 
from which proceed alternate or sometimes opposite veins ; these 
veins extend to the margin of the lobule, and are either simple, or 
become once forked about half-way their length; the veins when 
simple, or when divided, the anterior venules, bear a sorus at a short 
distance from. the edge of the lobule. 
Fructification on the back of the frond, scattered almost equally 
over the whole surface. Sori circular, small, quite destitute of 
' covering, arranged in a series near the margin of the lobules, and 
often becoming confluent in lines. Where 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. 
Spore-cases small, numerous, pale-brown. Spores ovate, smooth. 
Duration. The rhizome is perennial. The fronds are annual ; 
produced about May, and destroyed by the early frosts of autumn. 
This Fern is readily known from its congeners by its outline, which 
` is ovate-triangular with an elongated narrow point; by the pinnato- 
pinnatifid mode in which its fronds are divided; by the hairiness of 
its surface ; and by the direction of its pinne. 

