BFNA Title: Campylium
Author: L. Hedenäs
Date: July 2000
Edit Level: R
Version: 3

Bryophyte Flora of North America, Provisional Publication
Missouri Botanical Garden

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XX. CAMPYLIUM (Sullivant) Mitten, J. Linn. Soc. Bot. 12: 631. 1869  *  [Greek campylos, curved]


Lars Hedenäs


Hypnum sect. Campylium Sullivant in A. Gray, Man. Bot. No. United States ed. 2: 677. 1856


Plants small or medium-sized, green, yellowish green or brownish. Stems almost unbranched or irregularly to irregularly pinnately branched, with central strand, without hyalodermis, cells inside cortex thin-walled; paraphyllia absent or sometimes present; rhizoids smooth or slightly warty-papillose, slightly or strongly branched, rhizoids or rhizoid initials on stem at or just below leaf insertions; axillary hairs with 1--5 distal hyaline cells. Stem leaves from erect or erect-spreading base erect to spreading, occasionally distinctly falcate-secund, cordate, cordate-ovate, ovate or rounded-triangular, gradually or suddenly narrowed to short- or long-, channeled acumen, apex acuminate, not plicate, concave; margin plane, entire or slightly sinuose; costa short, double or single, ending before mid-leaf; median lamina cells linear, rarely shortly so, thin-walled or incrassate, porose or not, smooth; differentiated alar cells numerous, rectangular, quadrate or sometimes transversely rectangular, the more basal cells rectangular or shortly so, inflated and hyaline, widest cells 17--29.5 /um wide, forming a distinct (quadrate), broadly ovate, ovate or rectangular group along basal leaf margin, reaching from leaf margin 15--60% of distance to leaf middle at insertion, not or hardly decurrent. Branch leaves smaller and sometimes narrower than stem leaves. Sexual condition dioicous or autoicous; inner perichaetial leaves gradually or suddenly narrowed to narrowly acuminate apex, plicate or slightly so; margin bordered or not, entire or at shoulder weakly denticulate or occasionally with single, irregular teeth; costa short and indistinct, single or double, ending up to 30--50% way up leaf; lamina cells smooth; vaginula with paraphyses. Seta reddish. Capsule cylindrical, curved and horizontal to inclined; annulus separating; lid conical; peristome perfect; exostome cross-striolate on proximal outer surface, margin dentate or slightly dentate distally. Spores (10.5--)11--24 /um, finely papillose.


Species 4 (4 in the flora): widespread in the temperate to arctic zones of North America and Eurasia, with Campylium stellatum also in the southern temperate zone and at high elevations in the tropics.


Campylium species occur in ± mineral-rich wetlands that are mostly permanently wet or moist. They are relatively large (stem leaves up to 3.1 x 1.2 mm), distal portion of the leaves are erect to spreading, occasionally distinctly falcate-secund, acumen channeled, and leaf costa double and short. Both the leaf costa and the lamina cells are smooth. The more basal alar cells are inflated (widest cells 17--29.5 /um wide) and clearly different from the distal alar cells, the alar group is ovate or rectangular, and extends up along basal leaf margin, but extends only 30--60% of the distance from the leaf margin to the costa at the leaf insertion. The outer pseudoparaphyllia are foliose. The seta is long, to 45 mm, the exostome border strongly widened where the exostome pattern changes from cross-striolate to papillose, and the endostome cilia are sometimes appendiculate distally. Differences between members of this genus and those of Campylophyllum and Campyliadelphus are discussed with the latter. Members of Drepanocladus with similarly oriented leaves have differently shaped alar groups, being transversely triangular and extending from the leaf margin 60--100% of the distance to the costa at the leaf insertion. Other species of Drepanocladus may have approximately quadrate alar groups, but not ovate or rectangular and extending up along the leaf margin as are found in Campylium. The typification of Campylium was discussed by P. Isoviita and L. Hedenäs (1997).


SELECTED REFERENCES Andrews, A. L.. 1957. Taxonomic notes. XIII. The genus Campylium. Bryologist 60: 127--135. Engelmark, T.-B. & L. Hedenäs. 1992. A new species of Campylium from the northern Holarctic region. Lindbergia 16: 145--149. Hedenäs, L. 1989. Amblystegium longicuspis Lindb. & H. Arn., its status and taxonomic position. Lindbergia 14: 142--146. Hedenäs, L. 1997. A partial generic revision of Campylium (Musci). Bryologist 100: 65--88.



1. Autoicous; stem leaves erect or spreading from sub-sheathing base; leaf base broadly cordate-ovate, ovate or narrowly ovate, acumen when differentiated constituting at most 33% of leaf length.

2. Stem leaves slightly concave, 1.8--2.4 mm, from ± broadly cordate-ovate base gradually narrowed to longly acuminate apex, acumen not differentiated from rest of leaf. . . . 1. Campylium laxifolium

2. Stem leaves concave or strongly concave, 2.1--4.6 mm, from ovate or narrowly ovate base ± suddenly or more gradually narrowed to straight or slightly flexuose acumen, acumen frequently differentiated and then constituting 18--33% of leaf length . . . 2. Campylium longicuspis

1. Dioicous; stem leaves spreading or ± squarrose from sub-sheathing, erect to erect-spreading base; leaf base cordate or rounded-triangular, acumen frequently differentiated and then constituting 33--77% of leaf length.

3. Plants usually erect, irregularly or occasionally also somewhat pinnately branched; stem leaves 1.7--2 x 0.7--1.2 mm, acumen when differentiated constituting 40--65% (in Arctic plants rarely 33--40%) of leaf length; paraphyllia always lacking . . .  2. Campylium stellatum

3. Plants usually creeping, irregularly pinnately branched; stem leaves 1--2.3 mm x 0.4--1 mm, acumen when differentiated constituting 55--77% of leaf length; paraphyllia sometimes present . . . 3. Campylium protensum


1. Campylium laxifolium T.-B. Engelmark & L. Hedenäs, Lindbergia 16: 147. 1990


Plants medium-sized, erect or creeping, golden brown or golden yellow. Stems ± irregularly branched; paraphyllia lacking. Stem leaves erect or spreading from sub-sheathing base, leaf base cordate-ovate or broadly so, gradually narrowed towards leaf apex, 1.8--2.4 x 0.6--0.9 mm. Sexual condition autoicous.


Intermediately mineral-rich and slightly nutrient-enriched, often spring-influenced fens; low to moderately high elevations; Greenland; Alaska; n Europe (distribution incompletely known).


Campylium laxifolium differs from C. stellatum and C. protensum in being autoicous and in having erect or at least less distinctly spreading leaves than the last two. Its leaves are also more ovate than in the other two species, and are gradually narrowed towards the leaf apex. It is slightly smaller than C. longicuspis and has more weakly concave and more broadly ovate leaves without a differentiated acumen. Campylium laxifolium is known from only three localities in North America, but because it was recently described it can be assumed to be more widespread.


2. Campylium longicuspis (Lindberg & Arnell) Hedenäs, Lindbergia 14: 144. 1988 [1989]


Plants medium-sized, erect or creeping, glossy to golden brown. Stems unbranched or irregularly branched; paraphyllia lacking. Stem leaves erect to patent from sub-sheathing base, straight or slightly homomallous, leaf base ovate or narrowly so, acumen frequently differentiated and then constituting 18--33% of leaf length, 2.1--4.6 x 0.6--1.0 mm. Sexual condition autoicous.


Peaty shallow soil over limestone; low elevations; Greenland; Arctic Eurasia, Central Asia; known from a single Arctic North American locality in northeast Greenland.


Campylium longicuspis is easily separated from C. stellatum by ovate or narrowly ovate, rather than cordate or rounded-triangular stem leaves, and shorter leaf acumen, as well as by its autoicous rather than dioicous sexual condition. Differences between C. longicuspis and C. laxifolium are discussed with the latter. This species is very rare, and possibly overlooked in the Arctic.


3. Campylium stellatum (Hedwig) C. E. O. Jensen, Medd. Groenland 3: 328. 1887


Hypnum stellatum Hedwig, Sp. Musc., 280. 1801; Campyliadelphus stellatus (Hedwig) Kanda.


Plants medium-sized, usually erect, green to yellowish or brownish. Stems irregularly or sometimes irregularly pinnately branched; paraphyllia lacking. Stem leaves spreading or ± squarrose from sub-sheathing, erect to erect-spreading base, leaf base cordate or rounded-triangular, acumen frequently differentiated and then constituting 40--65% (in Arctic plants rarely 33--40%) of leaf length, 1.7--2.8 x 0.7--1.2 mm. Sexual condition dioicous.


Intermediately mineral-rich or mineral-rich fens, lake and river shores; low to high elevations; Greenland; Alta., B.C., Man., N.B., Nfld., N.W.T., N.S., Nunavut, Ont., Que., Sask., Yukon; Alaska, Colo., Conn., Ga., Iowa, Maine, Mich., Minn., Mo., Mont., N.Mex., N.Y., N.C., Ohio, Pa., Vt., Wash., Wis., Wyo.; Mexico; West Indies (Haiti); Central America (Guatemala); Eurasia; Pacific Islands (New Zealand).


When seen from above in the field, shoots of Campylium stellatum often look like small stars. It is closely related to C. protensum, from which it differs in its more erect growth, slightly larger size, and relatively shorter leaf acumen. Paraphyllia have never been seen in C. stellatum, whereas scattered plants of C. protensum have a few paraphyllia. To the south of and below the forest limit, C. stellatum occurs mainly in open (treeless) wetlands, whereas C. protensum is more frequent in swampy forests.


4. Campylium protensum (Bridel) Kindberg, Canad. Rec. Sc. 6(2): 72. 1894


Hypnum protensum Bridel, Musc. Rec. 2(2): 85, plate 2, fig. 3. 1801; Campyliadelphus protensus (Bridel) Kanda; Campylium stellatum var. protensum (Bridel) Bryhn


Plants small or medium-sized, usually creeping, green or sometimes yellowish green to yellow. Stems irregularly pinnately branched; paraphyllia sometimes present, uniseriate, narrowly triangular or ovate. Stem leaves spreading or ± squarrose from sub-sheathing, erect to erect-spreading base, leaf base cordate or rounded-triangular, acumen frequently differentiated and then constituting 55--77% of leaf length, 1--2.3 mm x 0.4--1 mm. Sexual condition dioicous.


Mineral-rich wetland habitats, in lowlands in swampy forests, at higher elevations sometimes in more open habitats, also lake and stream shores; low to high elevations; Greenland; Alta., B.C., Nfld., N.W.T., N.S.,Ont., Que., Yukon; Alaska, Colo., Idaho, Ill., Ind., Maine, Mass., Mich., Minn., Mont., Utah, Wash., Wis., Wyo.; Eurasia.


For differences between Campylium protensum and C. stellatum, see the notes with the latter.


Campylium treleasei (Renauld) Brotherus (Hypnum treleasei Renauld) is a synonym of Herzogiella adscendens (Lindberg) Z. Iwatsuki & Schofield (Z. Iwatsuki and W. B. Schofield 1973).




Grout, A. J. 1931. 1931. Moss Flora of North America north of Mexico. Vol. 3, part 2: 63--114, plates 15--29. New York.


Isoviita, P. and L. Hedenäs.1997. Campylium (Musci, Amblystegiaceae), a name typified by Pfeiffer. Taxon 46: 315--318.


Iwatsuki, Z. and W. B. Schofield.1973. The taxonomic position of Campylium adscendens (Lindb.) Mitt. J. Hattori Bot. Lab. 37: 609--615.