710 Aspidium spinulosum and its Varieties. [November, 
1. As to color. In characteristic specimens the typical form may 
be readily recognized by the peculiar shade of light-green that 
distinguishes it from the darker green of the variety. But as we 
soon find the former growing darker in color and blending with 
that of intermedium, especially as it approaches the so-called var. 
dilatatum, which as we have it in Eastern Massachusetts appears 
to be only a large, or higher developed state of spinulosum, we 
perceive that the color is not always to be depended upon as a 
specific character. 
2. As to form. The terms ovate-lanceolate, oblong-lanceolate 
and triangular-ovate may be applied to particular fronds of either 
form, and therefore can only be considered in connection with a 
series of characters as a whole. In good specimens of what is 
here recognized as typical spinulosum, the fronds will vary from 
ovate-lanceolate to triangular-ovate. In ordinary forms the two 
lowest pair of pinne are about of an equal length and set 
obliquely on the rachis; the two or three pairs of pinna imme- 
diately above are longer, more spreading, though still retaining a 
somewhat oblique arrangement on the rachis, and give an 
abruptly dilated appearance to that part of the frond; above, the 
more or less obliquely-set pinne gradually decrease toward the 
apex, and this comes as near as SRS to Swartz’s description 
of “ ovato-triangularis.” 
In characteristic specimens of intermedium the frond is usually 
-oblong-lanceolate in outline, with decidedly spreading pinnæ that 
are not obliquely set on the rachis. But these two forms run 
together frequently in all sorts of ways, and can only be regarded 
as of secondary importance. 
3. As to structure. In ordinary forms of spinulosum the fronds 
are only bipinnate, but this is equally true of the var. tnter- 
medium. 
4. As to the character of the scales. This is too unreliable to be 
considered in any other way than in connection with the whole 
series of characters. The darker scales with blackish centers are 
found only on large and vigorous specimens of the var. interme- 
_ dium and, but more rarely in this vicinity, var. dilatatum, but 
~ both of these forms frequently have pale brown scales like those 
ne 
5. As to the character of the indusium. In spinulosum the indu- A 
