■'j„h SXXXh
lj)n4airy)j .
POLYTRICHUM LÆVIGATUM.
Pohjtrielairn caule simplici, foliis arcte imbricatis ovatis
concavis integerrimis, nervo cras.so lamellato, capsula
late ovata cernua, calyptra lævi. (Tab.LXXXI.)
P. lævigatum. TVahl. FI. Lapp. p. 349.
P. glabratum. JVahl. M S S .—Mackenzie's Iceland,
p. 434.
Catbarinea glabrata. Hook. Tour in Iceland, vol. 1.
p. 24.
H a b . In nuda arena riparia aprica fluminis Muconio, prope p a-
gum Mueoniosuperiorcm et Ketkes-servando,Lapponiæ sylva-
ticæ Tonieiisis, frequentissime. Wahl. l. c.—Locis sterilibus
Islandiæ.
Radix densissime tomentosa. Caules cæspitosi, bi-trilineares,
simplices, curvuli. Folia &xcíe imbricata, erecta, appressa,
pallide fusco-viridia, v. lutesceiitia, ovata, concava, subcarnosa,
omnino integerrima, nervo lato intus insigniter lamellato,
lamellis undulatis. Perichcetialia reliquis minora, angustiora,
fuscescentia. Seta crassiuscula, subtrilinearis, flexuosa, rufo-
fusca. Capsida rufo-fusca, late ovata, horizontaliter inclinata.
Calyptra omnino pilis destituta.
P . IcBvigatum affords an excellent specimen of the curiously
lamellated nerve of the leaf, which in a greater or less degree is
common to all the species of the genus which have come under
my observation. Wahlenberg, its first and indeed only describer,
mentions the back of the leaf as having this appearance, if I understand
his words rightly, foliorum dorsum undulatim dila-
ia tu r,” which is not the ease with my specimens ; yet there can,
I think, be no doubt as to the identity of the plant. Schwaegrichen
has quoted it, though doubtfully, under the P.lcevigatum
of Bridel, which has leaves that are marginale and serrulate, and
with which it can therefore have no affinity.
Fig. 1, tuft of plants, nat. size. Fig. 2, the same, magn.
Fig. 3, leaf. Fig. 4, section of a leaf to show the structure of
the nerve. Fig. 5, perichætial leaf,—magn.
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