1903] Eaton,— Notes on Botrychium tenebrosum 275 
bulbous at the base and sheathed by the old remnants of stems as in 
B. simplex, which it also resembles in its general aspect and the size 
and markings of the spores, differing principally in having a simple 
lunate-segmented sterile lamina contiguous to the fertile, or at least 
above the middle of the stipe. The vernation is essentially that of 
B. simplex, both portions being erect, the very tip of the sterile 
flexed over the top of the fertile, but not bent down (Fig. 6). In a 
former paper! I have given its distinctive characters and shown it to 
be not B. simplex and later? I gave a detailed description. Mr. G. 
E. Davenport doubts the specific rank of this plant, regarding it as a 
depauperate B. matricariacfolium3 Both Prof. Underwood and I* 
replied to his criticisms, but it appears well in this place to give 
some of the chief points of difference between the species. In the 
accompanying plate Figures 1, 3, 4, and 5 represent pressed speci- 
mens of B. enebrosum, natural size; while Fig..2 shows a depau- 
perate, but fruiting, specimen of B. matricariacfolium. 
In vernation the buds of B. matricariacfolium are stout, the fertile 
lamina declined at the tip, resting on the top of the sterile of the suc- 
ceeding year, the sterile of the year embracing the whole with its tip 
distinctly declined and enveloping the top of the fertile. In B. 
tenebrosum, on the other hand, the buds are much smaller even in 
plants of the same size, they usually bear a bulbous thickening of 
dead stalk-bases, and both segments are erect (Fig. 6), as in Ø. 
simplex. In habit B. matricariacfolium is relatively stout, erect, 
usually bluish as if pruinose, and has no remains of old stalks at the 
base; B. tenebrosum is slender and weak, shining, yellowish, and 
bears two or three years’ accumulation of dead stalks. ‘The aspect 
of the two is strikingly different when they are growing together. 
The sterile lamina of B. matricariaefolium is more or less com- 
pound, the ultimate lobes being acute. Very rarely, indeed, a plant 
may be found, in which there are rounded lobes; the apex, however, 
is always acute (Fig. 10). In B. Zemebrosum the sterile frond is 
essentially that of a very lax B. Zuzaria, although thinner and with 
the apex emarginate. In both species sporangia are borne on the 
sterile laminae, but in B. matricariacfolium they are usually on a 
transformed compound lobe, making a miniature spike, while in B. 
1 Papers Boston Meeting of Fern Chapter, 25. 3 Fern Bulletin, X. 22. 
? Fern Bulletin, VII. 7. Alc, Xi. ga. 
