GENERA AND SPECIES. gl 
TEATS 2 ox 1t. 
ASPIDIUM SPINULOSUM. V.Intermedium. Willd. 
SPRING SHIELD FERN. 
Of the three varieties of A. spinulosum, this is the only 
ane which I have found in Kentucky. It is the A. interme- 
dium of Willdenow, not of Muhlenberg, the fern described 
by the latter being the A. spinulosum, which I have not been 
able to find in this State, though Riddell attributes it to the 
low, damp forests of Central and Northeastern Ohio.* The 
variety intermedium, however, is by no means uncommon 
in Kentucky, though I have seldom found it in Jefferson, 
Oldham, or Bullitt counties; but it grows in the greatest 
perfection at Big Clifty, Grayson County, as well as in 
Laurel, Rockcastle, Edmonson and Hardin counties. 
It is a very graceful fern, which collectors may readily 
mistake for the Lady Fern, but the round fruit-dots, the 
minute spiny teeth of the lobes, and the coarseness of its 
general appearance will serve to distinguish it from the 
*See Synopsis of the Flora of the Western States, by John L. 
Riddell, A. M., Cincinnati, 1835, p. 106; also Supplementary Cata- 
logue of Ohio Plants, Cincinnati, 1836, p. 21. It is difficult to deter- 
mine with certainty, from his descriptions, whether the latter of the 
two ferns described by Riddell is identical with our var. interme- 
dium, Willdenow (Eaton ?); but the forms are so variable that it 
may be questionable whether the A. spinulosum should be digni- 
fied with any varieties whatever, the Swartzian species being suffh- 
ciently comprehensive to include all its variations. From a careful 
comparison of the Kentucky specimens, which seem to belong to 
the var. intermedium, with Hooker’s typical A. spinulosum, kindly 
sent me by Mr. Davenport, I am convinced that the differentiation 
is so variable, the forms passing so imperceptibly into each other, 
that no particular type can be said to be wholly persistent. On this 
point see Hooker and Arnott’s British Flora, p. 570, note. 

