XX. CAMPYLIADELPHUS (Kindberg) R. S. Chopra, Taxon. Indian Mosses, 442. 1975 * [Greek campylo-, curved, and -adelphus, brother]
Hypnum sect. Campyliadelphus Kindberg, Bih. K. Svensk. Vet. Ak. Handl. 7(9): 16. 1883
Plants small to almost medium-sized, green, yellow-green or brownish. Stem irregularly to pinnately branched, with narrow central strand and without a hyalodermis; paraphyllia absent; rhizoids or rhizoid initials only on stem or at abaxial leaf costa insertion, smooth, slightly or strongly branched; axillary hairs with 1--4 distal hyaline cells. Stem leaves from almost erect to spreading base straight, falcate or ± recurved, rounded-triangular or ovate to broadly ovate, gradually or ± suddenly narrowed to long, channeled acumen, apex acuminate, not plicate, concave; marginal lamina cells 1-stratose, margin plane or near base slightly recurved, partly entire, partly sinuose or weakly and often obtusely denticulate; costa single, long, ending in mid-leaf or beyond, occasionally shorter and double; median lamina cells rectangular or linear, smooth; differentiated alar cells numerous, transversely rectangular to rectangular, more basal cells shortly rectangular to shortly linear and slightly inflated, widest cells 10.5--17.5(--21) \um wide, forming a distinctly or indistinctly delimited, quadrate, ovate or broadly ovate group, reaching from leaf margin 30--65% of distance to leaf middle at insertion, decurrent. Sexual condition dioicous. Inner perichaetial leaves gradually or ± suddenly narrowed to acuminate apex, plicate; margin entire throughout or at shoulder obtusely denticulate or with single obtuse teeth; lamina cells smooth. Capsule cylindric or shortly cylindric, curved and horizontal; peristome perfect; exostome margin dentate or slightly dentate above. Spores 8.5--20.5 \um.
Species 3 (1 in the flora): Holarctic region.
Species of Campyliadelphus grow on wet or periodically moist calcareous substrates. The species are medium-sized, stem leaves up to 2.4 x 0.7 mm, leaves straight, falcate or ± recurved, acumen long, channeled, costa single, long, or occasionally double and shorter. Both the costa and the lamina cells are smooth. The alar cells are almost homogeneous, only the basal cells are slightly inflated, with widest cells 10.5--19(--21) \um wide), and form a quadrate, ovate, broadly ovate, or transversely triangular group. The outer pseudoparaphyllia are foliose, while filamentose ones are only occasional. The seta is moderately long, up to 30 mm, the exostome border slightly strongly widened where the exostome pattern changes from cross-striolate to papillose, and endostome cilia are sometimes appendiculate distally. Campyliadelphus species are similar to Drepanocladus arcticus, D. cardotii, D. polygamus, and the species of Campylophyllum and Campylium in that their leaves are at least partly recurved or squarrose, and the leaf acumen is channeled. However, members of Campylophyllum deviate from those of the other genera in being smaller, having narrower outer pseudoparaphyllia, their double and short leaf costa often ends in a spine, having prorate lamina and often abaxial costa cells, and having only nodose endostome cilia. The alar cells are small as in Campyliadelphus, not inflated as in Campylium or Drepanocladus. The species of Drepanocladus mentioned above and those of Campylium are mostly larger than those of Campyliadelphus, have only foliose pseudoparaphyllia, and exostome borders more strongly widened where the pattern changes from cross-striolate to papillose. In addition, D. arcticus, D. cardotii, and the members of Campylium have almost always a short, double costa. The habitats of the species also differ between the four genera mentioned here, as can be seen from the comments after the respective descriptions.
SELECTED REFERENCES Andrews, A. L. 1957. Taxonomic notes. XIII. The genus Campylium. Bryologist 60: 127--135. Hedenäs, L. 1997. A partial generic revision of Campylium (Musci). Bryologist 100: 65--88.
1. Campyliadelphus chrysophyllus (Bridel) Kanda, J. Sci. Hiroshima Univ., Ser. B, Div. 2, Bot. 15: 264. 1975 
Hypnum chrysophyllum Bridel, Musc. Rec. 2(2): 84. plate 2, fig. 2. 1801; Campylium chrysophyllum (Bridel) Lange; C. chrysophyllum var. brevifolium (Renauld & Cardot) Grout; Hypnum chrysophyllum var. brevifolium Renauld & Cardot
Plants small to almost medium-sized, green, yellow-green or brownish. Stem leaves straight or falcate, acumen usually recurved in at least some leaves, rounded-triangular, ovate or broadly ovate; costa single and ending (40--)50--80% way up leaf, occasionally shorter and double.
Campyliadelphus chrysophyllus is distinct among the Campylium-like species in its usually single, long leaf costa (scattered specimens have shorter and double costae in at least some leaves), its quadrate, ovate or transversely triangular alar groups consisting of relatively small cells, basal cells being shortly rectangular to shortly linear and up to 10.5--17.5(--21) \um wide. The groups extend from the leaf margin 35--65(--80)% of the distance from leaf margin to leaf middle at the leaf insertion.
Rocks and soil, frequently temporarily wet, calcareous or otherwise mineral-rich habitats; low to high elevations but rarely above tree line; Alta., B.C., Man., N.B., Nfld., N.W.T., N.S., Ont., P.E.I., Que., Sask., Yukon, Ala., Ariz., Ark., Colo., Del., Fla., Ga., Ill., Ind., Iowa, Kans., Ky., La., Maine, Mich., Minn., Miss., Mo., Mont., Nebr., N.H., N.J., N.Mex., N.Y., N.C., N.Dak., Ohio, Okla., Ore., Pa., S.C., Tenn., Tex., Vt., Va., W.Va., Wis., Wyo.; Mexico, West Indies, South America (Colombia, Guatemala), Eurasia, North Africa.
Specimens named var. brevifolium (Renauld & Cardot) Grout tend to be relatively large plants of C. chrysophyllum. Hypnum unicostatum Müller Hal. & Kindberg was mentioned by H. A. Crum and L. E. Anderson (1981) as a synonym of C. chrysophyllum, but the type material belongs to Amblystegium radicale (Palisot de Beauvois) Schimper.
Crum, H. A. and L.
E. Anderson. 1981. Mosses of eastern