BFNA Title: Calliergonaceae
Author: L. Hedenäs 
Date: February 1, 2008
Edit Level: R
Version: 1

Bryophyte Flora of North America, Provisional Publication
Missouri Botanical Garden

BFNA Web site:


Return to Home

 XX. CALLIERGONACEAE (Kanda) Vanderpoorten et al.


Lars Hedenäs


Plants medium-sized to large; greenish, yellowish, brownish, or sometimes red. Stem distichously or radially branched, sometimes nearly unbranched; cortex of small and incrassate cells; hyalodermis present or not; pseudoparaphyllia foliose; paraphyllia absent; rhizoids red-brown, smooth, slightly branched; rhizoids or rhizoid initials on stem at or just before leaf insertions or from various points on stems and leaves; axillary hairs mostly well developed. Stem leaves straight or falcate (gradually curved) or from straight base suddenly curved, plicate or smooth; costa single and mostly long, or double and usually short; median laminal cells linear or short-linear, 1-stratose, smooth; alar cells differentiated or not, often inflated. Inner perichaetial leaves straight and erect, lanceolate or ovate or oblong or slightly obovate, plicate or smooth; costa usually well developed, single; vaginula with paraphyses or naked. Seta long, smooth. Capsule cylindric, curved and horizontal, stomata long-pored; annulus separating or not; operculum conic; peristome perfect, exostome yellow-brown or brownish, more or less  reticulate on outer surface proximally, rarely entirely cross-striolate, papillose distally, with dentate or slightly dentate margin and an exostome border ± widened at zone of transition in outer peristomial layer pattern, endostome with high basal membrane, segments long and not or narrow-perforate, cilia nodose. Calyptra cucullate, smooth.


Genera 7, species ca. 22 (7 genera, 19 species in the flora): temperate to sub-polar regions worldwide, tropical mountains.


Genera of the Calliergonaceae are fairly well circumscribed based on both morphology and molecular data, and are well differentiated from the Amblystegiaceae. All species, except sometimes Scorpidium revolvens and S. scorpioides, have a reticulate outer surface of the proximal portion of the exostome, whereas all members here treated in the Amblystegiaceae, except Tomentypnum and Conardia, are cross-striolate on the outer basal exostome. Many Calliergonaceae species become a translucent red when growing in habitats exposed to sunlight, this never being the case among the Amblystegiaceae.


The genera Calliergon, Loeskypnum, Sarmentypnum, Straminergon, and Warnstorfia are further characterized by many morphological features. When shoots grow erect, these are radially rather than distichously branched, except in species that are sparsely branched. Rhizoid initials, and sometimes also rhizoids, are frequently found in various parts of the leaf lamina, especially close to the leaf apex. Leaf-borne rhizoid initial cells are easily recognized in being slightly wider than the surrounding lamina cells and in lacking the pigments of the latter. Among the Amblystegiaceae genera, rhizoid initials and rhizoids are found in leaves only in Conardia, in which they often occur both close to leaf apices and on the costa abaxially, and in Tomentypnum, in which they are found only on the abaxial surface of the costa. The inner perichaetial leaves are smooth, the vaginula naked or bearing at most a few paraphyses, and annulus is not separating. The two genera Scorpidium and Hamatocaulis, which lack the character states enumerated for the other five genera, are characterized by their small alar groups or by lacking differentiated alar cells, and a unique form of leaf curvature. Curved leaves in members of these two genera have an almost straight base and are abruptly curved above, whereas curved leaves in other members of this family and in the Amblystegiaceae are gradually curved along their entire length.


SELECTED REFERENCES Hedenäs, L. 1993. A generic revision of the Warnstorfia-Calliergon group. J. Bryol. 17: 447--479. Hedenäs, L. 2003. Amblystegiaceae (Musci). Flora Neotropica, Monograph 89: 1--107. Hedenäs, L. 2006. Additional insights into the phylogeny of Calliergon, Loeskypnum, Straminergon, and Warnstorfia (Bryophyta: Calliergonaceae). J. Hattori Bot. Lab. 100: 125--134. Hedenäs, L., G. Oliván and P. Eldenäs. 2005. Phylogeny of the Calliergonaceae (Bryophyta) based on molecular and morphological data. Plant Syst. Evol. 252: 49--61. Hedenäs, L. and A. Vanderpoorten. 2007. The Amblystegiaceae and Calliergonaceae. In: A. E. Newton and R. Tangney (eds.). Pleurocarpous Mosses: Systematics and Evolution. The Systematics Association Special Volume Series 71. Pp. 163--176. Vanderpoorten, A., L. Hedenäs, C. J. Cox and A. J. Shaw. 2002. Phylogeny and morphological evolution of the Amblystegiaceae (Bryopsida). Molec. Phylog. Evol. 23: 1--21. Vanderpoorten, A., L. Hedenäs, C. J. Cox and A. J. Shaw. 2002. Circumscription, classification, and taxonomy of Amblystegiaceae (Bryopsida) inferred from nuclear and chloroplast DNA sequence data and morphology. Taxon 51: 115--122.


1. Stem with full or partial hyalodermis.

2. Inflated alar cells numerous and forming a large transverse-triangular group that reaches from leaf margin ± to costa; rhizoid initials frequently present in leaves, especially near leaf apex. 7. Sarmentypnum (in part), p. xx.

2. Inflated alar cells few, in small transverse-triangular or isodiametric group that reaches at most about halfway from leaf margin to costa; rhizoid initials never present in leaves. 2. Scorpidium, p. xx

1. Stem without an hyalodermis.

3. Stem lacking central strand; stem leaves usually plicate; alar cells of stem leaves not differentiated from other basal cells........................................................................... 1. Hamatocaulis, p. xx.

3. Stem with central strand; stem leaves not or hardly plicate; alar cells of stem leaves differentiated, small or inflated, sharply or gradually delimited from surrounding cells.

4. Alar cells of stem leaves slightly inflated, incrassate to strongly so, indistinctly delimited from surrounding cells; axillary hairs well developed, abundant, with early yellowish or brownish distal cells; plant often yellow-brown or copper-brown, never red.... 4. Loeskypnum, p. xx.

4. Alar cells of stem leaves inflated or strongly so, thin-walled or sometimes incrassate, distinctly delimited from surrounding cells, except in Calliergon cordifolium and Warnstorfia fluitans; axillary hairs well developed and abundant or small and rare, hyaline except in Sarmentypnum trichophyllum (brownish); plant color various, sometimes red.

5. Stem leaves straight or falcate, from (oblong-ovate or) ovate or ± triangular or cordate basal part gradually narrowing to acuminate to acute or obtuse leaf apex.

6. Dioicous; translucent red color often present; pseudoparaphyllia broad; alar cells forming a large transversely triangular group that is distinctly delimited from the surrounding cells and ± reaches the costa (in late snow beds or in cold springs in mountainous areas, modifications with less well delimited alar groups occur). 7. Sarmentypnum (in part) , p. xx.

6. Autoicous; translucent red color extremely rare; red colors when present usually overlain by brown pigments, giving a reddish brown color; at least some outer pseudoparaphyllia narrow, often lanceolate; alar cells forming a rather narrowly transversely triangular group that may reach the costa, or an isodiametric group which, together with the supra-alar cells, often form an ovate group along basal margin, alar groups somewhat indistinctly delimited from the surrounding cells. 5. Warnstorfia, p. xx.

5. Stem leaves ± straight and ovate, broadly ovate, or rounded-triangular, in distal part ± abruptly narrowing to rounded, rounded-obtuse or rounded-apiculate apex.

7. Stem leaves broadly ovate to broadly rounded-triangular, with broadly obtuse or rounded apex; axillary hairs 2--8(--10)-celled, large and abundant. 3. Calliergon, p. xx.

7. Stem leaves ovate to rounded-triangular, with shortly rounded-apiculate or rounded apex; axillary hairs 1--4(--5)-celled, weak and usually sparse.

8. Stem leaf apex rounded; alar groups ovate or broadly ovate, along basal margin of leaf; plants usually sparsely branched; plants pale or whitish green to yellow-green.............................. 6. Straminergon, p. xx.

8. Stem leaf apex usually rounded-apiculate, rarely rounded; alar groups ± transverse-triangular; plants sparsely to more richly branched; plants deep green to clear red................. 7. Sarmentypnum (in part) , p. xx.