By Willard N. Clute.
Nephrodium Molle in Florida.--Mr. James H. Ferriss recently called my
attention to specimens of _Nephrodium molle_ received from Florida with
the suggestion that this species might be native to the State. On this
point, Reasoner Brothers, the well-known plant dealers, have written him
that they no longer grow the fern since it is abundant in a wild state
and easily obtained when wanted. There seems to be no reason why the
species should not occur in Florida, since _Nephrodium patens_, a close
ally, is common there; but as _N. Molle_ is not listed from the United
States, we publish this note in the hope of drawing out further
information about it and of ascertaining if possible whether _Molle_ is
actually native, or only a well naturalized escape. Superficially,
_molle_ and _patens_ are so very much alike that it is very easy to
confuse them. The venation, however, is a sufficiently distinct feature.
In _patens_ the basal veins in each pinnule run to the sinus, uniting
at, or just below, it; in _molle_ they unite at some distance from the
sinus from whence a single vein runs to the sinus. According to Jenman,
_patens_ has a creeping horizontal rootstock with the fronds arranged in
two lines along it, while _molle_ has an erect rootstock. The fronds of
the latter are also softer and thinner.
Naturalization of an Exotic Fern.--Records of ferns becoming naturalized
in new regions are very rare. _Pteris serrulata_ is probably our most
conspicuous American example, having been found as an escape in several
places, while it is known to grow abundantly on old walls in New
Orleans. I have also reported the occurrence in the same place, of an
abundance of _Pteris longifolia_ previously known in the United States
from Florida alone. In the Fern Bulletin for January, 1898, mention is
made of fronds of _Pteris tremula_ seventeen inches high collected from
the walls of a tunnel in New York City, and the same article mentions a
Japanese species of _Athyrium_ that has become naturalized on Staten
Island, New York. To this meagre list, it is with much pleasure that I
add another species in the shape of the Japanese climbing fern
(_Lygodium Japonicum_). This Mrs. A. P. Taylor has sent to me from
Thomasville, Georgia, where she finds it in profusion along the sides of
a deep ditch. The station is not far from a greenhouse from whence the
plants doubtless came in the first place, but all indications point to a
further spread of this pretty and interesting species.
The Forms of the Spinulose Wood Fern.--It is well-known to fern students
that much more attention has been paid to the forms of ferns on the
other side of the Atlantic than on this. Since the same species are
often common to both localities, it is but natural that the early
students of American ferns should pay rather more attention to the mere
forms of species common to Great Britain and America than their
systematic importance warrants. This is especially true of the variable
_Nephrodium spinulosum_ whose variety _intermedium_, I am convinced, is
scarcely more than an ecological form. In this view I am glad to be
borne out by Mr. A. B. Klugh, who has recently examined nearly 500
Canadian specimens and come to the same conclusion. Mr. Klugh writes:
"In number of glands on the indusium, in color of scales on the stipe,
in shape and cutting of the frond and in degree of obliquity of the
pinnae, we have a perfect gradation from true _spinulosum_ to typical
_intermedium_. Our commonest form has the indusium glandular and the
scales of the stipe pale brown without a dark centre." In a series of
fronds examined there seemed to be no corelation between the color of
the scales and the glands on the indusium, there being fronds with light
scales and no glands, others with dark centered scales and many glands,
and still others the exact opposites of these. _Intermedium_ may be
distinguished as a form, but it is certainly far less distinct than such
plants as _Nephrodium cristatum Clintonianum_ or _Pteris aquilina
pseudocaudata_ and would probably never have appeared in our lists but
for the fact that much has been made of the forms of this species in
other lands.
Elevation and Lycopodium selago.--Some time ago I noted in this series,
that a party of botanists on a visit to Mt. Ktaadn had found _Lycopodium
selago_ grading into _L. lucidulum_ as they traveled downward from the
summit, and quoted their opinion that _L. selago_ is a xerophytic form
of _L. lucidulum_. In regard to this, Mr. J. B. Flett writes that if the
one intergrades with the other, it is doubtless due to elevation or
cold, and not to xerophytic conditions. As to the plant's habitat in the
northwest, he says: "I have never seen _L. selago_ growing in a really
dry place, I have studied this form in the field from Washington through
British Columbia into the islands of southwestern Alaska and on the
Aleutian Islands, also on the tundra between Cape Nome and Cape York. No
one familiar with this tundra region would ever assert that there are
any xerotic forms on it."