GENERA AND SPECIES. 99 
PLATE XXXVI. 
ASPIDIUM ACROSTICHOIDES. Swartz. 
WINTER FERN—CHRISTMAS FERN. 
This is undoubtedly the most commonly met with of all 
the Shield Ferns. In fact it is the best known of our native 
ferns, growing every where without any special habitat. 
The best specimens have usually been obtained, however, 
along the banks of streams. It is found as well in ex- 
posed situations upon high rocks, as in ravines or deeply- 
shaded woods. 
The average size of the plant is about twenty inches, 
but some attain a height of over two feet. It has a strong, 
tufted root-stock; the stipe covered very profusely with 
membranaceous, chaffy scales; the frond lanceolate, pin- 
nate; the pinne lanceolate, with a well-marked triangular 
lobe on the upper side. The frond becomes very narrow 
and contracted toward the apex, probably on account of 
the pabulum supplied to the leaf being used up in fruit- 
patches, which cover the entire surface of this constricted 
portion. The plant is very variable, being sometimes 
broad and foliate, when the fronds are generally sterile, 
and not so strongly marked with spines. ‘The fertile 
fronds are much narrower than the sterile, the pinnz be- 
coming crisp and wavy. The Plate represents the frond 
near the middle, with the point bent, showing the fructifi- 
cation beneath. 
This fern is very hardy, and is consequently very suit- 
able for out-door cultivation. 

