160 THE ROCK SPLEENWORTS. 
the backs of the ordinary fronds in a single row near the 
edge of each pinnule, the individual sori oblique to the 
rachis. 
In size, shape and habitat, this species seems to stand 
halfway between the maidenhair and ebony spleenworts. 
It was once considered a variety of the latter and is 
sometimes called the little ebony spleenwort. The points 
by which it may be distinguished from the maidenhair 
spleenwort have been mentioned. It may be well, also, to 
contrast it with the ebony spleenwort. For all their re- 
semblances, it will be found upon comparing the two that 
they have very little in common. 
In parvulum the fronds are small, thick, stiff, with en- 
tire, deflexed pinnae. Fertile and sterile fronds are of the 
same size. 
In ebeneum the fronds are larger, thin, flexible, with 
serrate horizontal pinne and the fertile fronds are much 
the taller. 
Asplenium parvulum is found from Virginia and Kan- 
sas south and southwestward to the tropics. In the 
mountains of Jamaica it frequently grows on wayside 
banks and old stone walls, often in full sun. 
The Ebony Spleenwort. 
The ebony spleenwort (Asplentum ebencum) loves the 
rock as much as any of its kin, but only rarely is it 
found on the shelving sides of cliffs. I have found it 
thus along the Palisades of the Hudson, but it had evi- 
dently strayed down from its home at the top. It espe 
cially delights in thin stony soil and comes to its best in 
half wooded lands in a tangle of small bushes, brambles 
and clumps of the New York and boulder ferns. It also 
