Hudson’s spleenwort. 
253 
The roots are black, very long, slender and penetrating ; in 
the fissures of rocks they often run to a great depth, and the 
plant becomes so completely and firmly wedged that it is a 
task of great difficulty to obtain a living plant from such situ- 
ations. The rhizoma is brown, tufted, and densely covered with 
bristle-like scales ; similar scales are also scattered here and there 
on the stem. The young fronds make their appearance in May, 
arrive at maturity in August, and remain uninjured throughout 
the winter ; except in seedling plants they are always fertile. 
The form of the frond is various ; in some situations it is of 
erect growth, nearly linear and simply pinnafe, the pinnae being 
stalked and lobed : in this state seed is abundantly produced, 
and the masses when full grown are perfectly circular. Of the 
three entire fronds represented in the illustration at page 249, 
that to the right-hand is intended for this variety, and the por- 
tions of fronds to the right and left show the situation of the 
veins, and the mode of fructification ; every part of the plant is 
perfectly flat, and the entire plant rigid. A second variety, of 
pendant growth and larger size, is lanceolate in form : the pin- 
nae are pinnate ; the pinnules stalked, serrated, and somewhat 
quadrate. The fronds often measure a foot in length, and some- 
times fifteen and even eighteen inches ; they usually issue from 
dark holes or crevices, or depend from the roofs of sea-caves ; 
and the lower pair of pinnae are often bleached, of small size, 
weak and imperfect : the surface of the frond is generally flat : 
the middle frond of the three represents this form, and the de- 
tached pinnule immediately adjoining it shows the veins and 
incipient involucres. A third variety is of nearly erect growth, 
but bends over at the extremity ; and the entire frond, together 
with each individual pinnule, possesses such a rigid and inflex- 
ible convexity, that it is next to impossible to flatten it by pres- 
sure : the frond to the left is intended to represent this variety, 
but the convexity is not expressed. 
The lateral veins are branched, a branch running to the ex- 
treipity of each serrature ; the clusters of capsules are attached 
near the extremity of the veins, and somewhat alternately, one 
branch bearing a mass and the next being without one : each 
cluster is at first elongate and linear, and covered by a linear, 
