BFNA Title: Oxyrrhynchium
Author: M. S. Ignatov
Date: September 25, 2009
Edit Level: R
Version: 1

Bryophyte Flora of North America, Provisional Publication
Missouri Botanical Garden

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XX. Oxyrrhynchium (Bruch, Schimper & W. Gümbel) Warnstorf, Krypt. Fl. Brandenburg 2: 781. 1905, name conserved  *  [Greek oxys, acute, and rhynchos, rostrum, alluding to acutely beaked operculum]

Michael S. Ignatov


Eurhynchium subgen. Oxyrrhynchium Bruch, Schimper & W. Gümbel, Bryol. Eur. 5: 224. 1854



Plants medium-sized, in loose tufts, light to whitish or brownish green, glossy. Stems prostrate to arching, with central strand, loosely, occasionally more densely terete-foliate, irregularly, sometimes rather regularly branched, branch foliage terete, subcomplanate to sometimes distinctly complanate, especially when leaves rather remote; axillary hairs 2--3-celled; juvenile branch leaves acute. Stem leaves loosely arranged to occasionally loosely imbricate, erecto-patent to patent, broadly ovate to ovate-lanceolate, broadest at 1/3--1/7 of leaf length; long- or short-acuminate, slightly to moderately strongly concave, smooth; margins serrate to serrulate; costa reaching 0.5--0.7 of leaf length, ending in a spine, sometimes with additional teeth abaxially; juxtacostal basal cells shorter and slightly broader, gradually transitioning to mid leaf cells; cells adjacent to decurrency enlarged, in small conspicuous pellucid group; mid leaf cells elongate; moderately thick-walled. Branch leaves slightly to strongly differentiated, in the latter case more elliptic in shape with the broadest point of leaf at 1/2--1/3 of leaf length; more shortly acuminate to acute than stem leaves, often asymmetric at base, twisted at mid-leaf and more strongly serrate and with costa more strongly toothed distally, ending in a stouter spine. Sexual condition dioicous; perichaetial leaves abruptly contracted to long, reflexed acumen from sheathing base. Seta red-brown, rough. Capsule red-brown, inclined to horizontal, elongate, curved; annulus separating in fragments; operculum low-conic and then contracted to long narrow beak; peristome xerocastique, perfect. Calyptra naked. Spores 10--13 \um.


Species 10--15 (1 in the flora): worldwide, but absent in cold boreal regions.


The segregation of Oxyrrhynchium from Eurhynchium was initially accepted by many authors, including V. F. Brotherus (1925). However, it was later placed back into Eurhynchium (e.g., H. Robinson 1962, H. A. Crum and L. E. Anderson 1981). The phylogenetic analysis of M. S. Ignatov and S. Huttunen (2002) demonstrated that Eurhynchium in the broad sense was polyphyletic, and Oxyrrhynchium belonged to a different subfamily different than Eurhynchium in the strict sense. Oxyrrhynchium is distinct in having a rough seta (smooth in Eurhynchium), and a tendency for subcomplanate foliage, this not observed in Eurhynchium. Aquatic species closely related to Oxyrrhynchium are treated as Donrichardsia (cf. S. Huttunen et al. 2007).


1. Oxyrrhynchium hians (Hedwig) Loeske, Verh. Bot. Vereins Prov. Brandenburg 49: 59. 1907


Hypnum hians Hedwig, Sp. Musc. Frond., 272, plate 70,  fig. 11-14. 1801; Eurhynchium hians (Hedwig) Sande Lacoste; Oxyrrhynchium rappii R. S. Williams, O. hians subsp. rappii (R. S. Williams) Wijk & Margadant


Stems to 3--10 cm, branches to 4--12 mm. Stem leaves 0.7--1.3 x 0.5--0.8 mm; basal cells near costa 7--10 \um wide; cells adjacent to decurrency 12--20 x 10--15 \um; mid-leaf cells (25--)40--60(--80) x 5--7 \um. Branch leaves 0.8--1.1 x 0.4--0.7 mm. Seta 10--25 mm. Capsule ca. 2 mm.


Soil, more commonly open humus in forest, rocks, rotten logs, tree bases, usually mesic to wet conditions, deep shade to sunny places; 0--800 m; B.C., N.S., Ont., Que.; Ala., Ariz., Ark., Calif., Conn., Del., Fla., Ga., Idaho, Ill., Ind., Iowa, Kans., Ky., La., Maine, Md., Mass., Mich., Minn., Miss., Mo., Nebr., N.J., N.Y., N.C., Ohio, Okla., Pa., S.C., Tenn., Tex., Vt., Va., W.Va., Wis.; Europe; Asia; Africa; Atlantic Islands.


Oxyrrhynchium hians is a highly variable species. It ranges from densely foliate, almost tumid phenotypes to very remotely and complanately-foliate plants, the latter in shaded habitats. Leaves vary from broadly elliptic and sometimes almost orbicular to narrowly ovate-triangular. In Florida, plants with multi-spinose costa were described as O. rappii. However, R. S. Breen (1963) found this character to be unstable, sometimes varying along a single stem; H. A. Crum and L. E. Anderson (1981) also agreed that this name refers to no more than a form of O. hians. Eurhynchium semiscabrum E. B. Bartram known from Mexico and more southern countries is similar to O. hians and may, at some point, be found in southern states, especially in Florida. It differs from O. hians primarily in its synoicous inflorescence. Despite a broad distribution in the East and its somewhat weedy nature, O. hians is mostly absent in the West there it has been found only twice, in Vancouver, British Columbia, and in California, growing in man-made habitats (lawns) and should be considered a fairly recent introduction.



Breen, R. S. 1963. Mosses of Florida, an illustrated manual. University Presses of Florida: Gainesville. xliv + 273 pages.


Brotherus, V. F. 1925. Musci (Laubmoose). 2 Hälfte. In A. Engler (ed.), Die natürlichen Pflanzenfamilien, ed. 2. Berlin.


Crum, H. and L. E. Anderson 1981. Mosses of Eastern North America, Vols. 1--2. Columbia University Press, New York.


Huttunen, S., A. A. Gardiner and M. S. Ignatov. 2007. Advances in the knowledge of the Brachytheciaceae (Bryophyta). In A. E. Newton & R. S. Tangney (eds.) Pleurocarpous Mosses: Systematics and Evolution. Systematics Association Special Volume 71: 117--143.


Ignatov, M. S. and S. Huttunen 2002 [2003]. Brachytheciaceae (Bryophyta)---a family of sibling genera. Arctoa 11: 245--296.


Robinson, H. 1962 [1963]. Generic revisions of North American Brachytheciaceae. Bryologist 65: 73--146.