27.
Sphagnum cuspidatum
Hoffman, Deutschl. Fl. 2: 22. 1796.
Sphagnum cuspidatum
var.
plumosum
Nees & Hornschuch;
S. faxonii
Warnstorf;
S. virginianum
Warnstorf
Plants
slender and weak-stemmed, moderate-sized, flaccid and plumose in aquatic forms to more compact in emergent forms, spreading branches often con-spicuously falcate, giving capitulum a twisted appearance; green to yellow, often tinged with red, red-brown or brown in capitula.
Stems
green; superficial cortex of 2-3 layers, 2 layers of enlarged thin-walled cells.
Stem leaves
triangular-ovate, more than 1.2 mm, usually appressed; apex acute to apiculate, hyaline cells rarely septate or porose, apical region often fibrillose.
Branches
mostly unranked to weakly 5-ranked, often conspicuously falcate, leaves greatly elongated at distal end.
Branch fascicles
with 2 spreading and 2-3 pendent branches.
Branch stems
green, but often pinkish at the proximal ends, with cortex enlarged with conspicuous retort cells.
Branch leaves
ovate-lanceolate to lanceolate, 1.6-5 mm, falcate toward branch tips, when dry often undulate and recurved, rarely weakly serrulate along the margins in submerged forms, leaves from middle of spreading branches with length to width ratio less than or equal to 1:0.28; hyaline cells length to width ratio in apical convex surface region 8:1 or more, convex surface with 0-1 small round pores at apex, concave surface with faint round wall thinnings in cell apices and angles; chlorophyllous cells triangular to trapezoidal in transverse section, broadly exposed on the convex surface and exposed slightly on the concave surface.
Sexual condition
dioicous.
Spores
29-38 µm; covered with large papillae on both surfaces, appearing pusticulate; proximal laesura less than 0.5 spore radius.
Widespread forming wet carpets in ombrotrophic to weakly minerotrophic mires; low to moderate elevations; N.B., Nfld. and Labr. (Nfld.), N.S., Ont., Que.; Ala., Conn., Del., Fla., Ga., Ill., Ind., Kans., Maine, Md., Mass., Mich., Minn., Miss., N.H., N.J., N.Y., N.C., Ohio, Pa., R.I., S.C., Tenn., Vt., Va., W.Va., Wis.; Europe.
Sporophytes are occasional, capsules mature in early to mid summer.
Distinguishing
Sphagnum cuspidatum
from
S. viride
is sometimes difficult, as both occur over a similar geographic range and both grow in wet carpets.
Sphagnum cuspidatum
has narrower branch leaves and usually a distinct red tinge at the branch bases within the capitulum.
