|
BFNA Title: Pseudocampylium |
|
XX. Pseudocampylium
Vanderpoorten
& Hedenäs, J. Bryol. 31: xx. 2009 * [Greek pseudes, false, and genus Campylium] Alain Vanderpoorten Plants slender in soft, loose, light green to
yellowish mats. Stems creeping, freely and irregularly branched;
central strand of small, thin-walled cells present; rhizoids smooth; axillary
hairs with a single, elongate, rectangular to long-rectangular, of 1 brown
basal cell and up to 4 elongate hyaline distal cells; paraphylia sparse,
narrowly lanceolate to ovate-lanceolate. Stem leaves wide-spreading
to squarrose wet or dry, cordate-ovate, long-acuminate, narrowed to base,
decurrent, concave at basal angles; margin plane or slightly recurved in alar
region, entire or nearly so; costa ending at mid-leaf to reaching 3/4 of leaf
length; alar cells few, differentiated, somewhat inflated, hyaline, the
widest 14--25 \um in width. Sexual
condition autoicous. Perichaetial
leaves erect, lanceolate. Capsule horizontal, curved, 1.5--2 mm, when dry
constricted below mouth; operculum conical; annulus of 2--3 rows of
separating cells; exostome yellow-brown, cross-striolate basally, papillose
and dentate distally, trabeculate at back; endostome cilia nodose. Spores
finely roughened. Species: 1 (1
in the flora): widespread, but
nowhere frequent: North America; Central America; Pseudocampylium
radicale, the only species in Pseudocampylium, has been shifted variously among
Campylium, Leptodictyum and, most recently, Amblystegium.
Its slender habit is reminiscent of Amblystegium serpens, while its
wide-spreading to squarrose leaves recall Campylium, and its fairly
long laminal cells are somewhat similar to those of Leptodictyum.
Molecular evidence shows that P. radicale is unrelated to these genera
and is nested within a clade including similarly slender species with a weak
or even absent costa, including Pseudoamblystegium subtile and
Serpoleskea confervoides, but also a morphologically heterogeneous
assemblage of genera including Anacamptodon and Hygrohypnum.
All these taxa have fairly narrow ecological ranges, and it seems that
habitat specialization has triggered an array of contrasting morphologies
among taxa that do, however, share a common ancestor.
SELECTED REFERENCES Hedenäs, L.
1997. A partial revision of Campylium (Musci). Bryologist 100: 65--88. Vanderpoorten, A. and L. Hedenäs.
2009. New combinations in the Amblystegieceae. J. Bryol. 31: xx.
2009
1. Pseudocampylium radicale (P. Beauvois) Vanderpoorten & Hedenäs, J. Bryol. 31: xx. 2009 Hypnum radicale P. Beauvois, (Prodr. Aethéogam., 68. 1805; Amblystegium saxatile Schimper; Campylium radicale
(P. Beauvois) Grout Stem leaves
0.5--0.7 x 0.8--1.6 mm; median leaf cells 30--60 x 5—9 \um, 4--8:1. Seta elongate, 2--4.5 cm, smooth. Spores 9--18 \um. The morphology
of Pseudocampylium radicale is may
be misleading, since the taxon shares with Campylium in the broad sense spreading to squarrose stem leaves.
Specimens with non-squarrose leaves also bear much resemblance with Hygroamblystegium varium subsp. varium var. humile, which occurs in similar habitats. Pseudocampylium radicale may, however, be distinguished from the
latter by the decurrency of its stem leaves. Humus and
litter in mineral-rich and eutrophic wet meadows and swamps, often under a
fairly dense grass and sedge vegetation; 0--3000 m; Alta., B.C., Labr., N.B.,
N.S., Ont., Man., Que., Sask., N.W.T.; Ala., Colo., Conn., Del., Fla., Ga.,
Idaho, Ill., Ind., Kans., Ky., La., Maine, Md., Mich., Miss., Mo., N.H.,
N.J., N.Y., N.C., Ohio, Oreg., Pa., R.I., S.C., Tenn., Va., Vt., Wash.,
W.Va.; Mexico; Central America; Europe. |
