92 Rhodora |May 
Reference has been made to the fact that neither D. C. Eaton nor 
Dr. Christ could distinguish P. Lemmoni from P. mohrioides, var. 
elegans. Well developed fronds of the two are almost identical and 
P. Lemmoni has the scaleless surfaces of theoretical P. mohrioides, 
and the pits in its lower faces are unusually conspicuous. In only 
one character, apparently, can the two be distinguished with satis- 
faction: in var. elegans the scales at the base of the stipe are castaneous 
and subcoriaceous as in typical P. mohrioides; in P. Lemmoni paler 
and thinner as in vars. plicatum and scopulinum. In their extremes 
P. Lemmoni and P. mohrioides, var. scopulinum are well differentiated, 
but certain small plants of the former too closely simulate plants of 
the latter with unusually pinnatifid pinnae; and in view of their both 
possessing the essential characters of P. mohrioides and the failure of 
the spinulose teeth of var. scopulinum to retain the constancy one 
might wish them to, it seems the part of sound classification to treat 
P. Lemmoni as 
P. MOHRIOIDES, var. Lemmoni (Underw. ) n. comb.  Aspidium 
mohrioides D. C. Faton, Ferns of N. A. ii. 251, t. Ixxx. figs. 4-9 (1880), 
as to Lemmon plant figured. P. Lemmoni Underw. Our Nat. Ferns, 
ed. 6: 116 (1900). 
Besides agreeing in all their fundamental specific characters, typical 
P. mohrioides and its vars. scopulinum and Lemmoni are amazingly 
similar in their selection of habitat. Bory’s statement, based upon 
the observations of the original collectors of the Falkland plant, was 
that "elle croft dans les fentes des rochers" and the latest statement, 
by Skottsberg, is similar: "Rocky places, often deep down in crevices, ” 
while in the "stone-runs" “Two ferns are found in solitary tufts be- 
tween the blocks, Blechnum magellanicum and Polystichum mohrioides, 
both finely developed."! How strikingly like Eaton’s account of the 
type-station of var. Lemmoni: "Mr. Lemmon writes that this fern 
grows in loose and moist granitic soil, the root-stocks hidden under 
rocks;’” or like Bradley's account of the type-region of var. scopu- 
linum in the Teton Canon of Idaho: “we climbed a sharp slope of 
stumbling rubbish, and then found ourselves on a narrow crest, 
overlooking an immense cafion, the Great Téton Canon 
The descent from this crest is very steep; and, in dodging falling 
masses of rock, started by those behind him, Mr. Bechler unfortunately 
! Skottsberg, A Botanical Survey of the Falkland Islands, Kungl. Svenska Veten- 
skapsakad. Handl. 1. No. 3: 9, 114 (1913). 
? Eaton, l. c. 252 (1880). 
