Ephemeraceae

Belongs within: Dicranideae.

The Ephemeraceae are a family of minute, morphologically reduced mosses, consisting of persistent protonemata from which the ephemeral plants grow when conditions permit. They are usually found in habitats that are marginal for other mosses, such as sunny patches (Bryan 2007). The capsule may be cleistocarpous as in species of Ephemerum or open by a dehiscence line as in Nanomitriopsis longifolia.

Characters (from Bryan 2007): Plants leafy ephemerals, less than 3 mm, solitary, scattered, or gregarious on sparse or abundant protonemata with upright, aerial, determinate branches; green, pale-yellow, or brown. Stem virtually absent or to 1 mm (to 3.7 mm in Micromitrium synoicum), rhizoids absent or few. Leaves rarely more than 12; proximal leaves small, broadly triangular to ovate, ecostate, apex acuminate; distal leaves becoming larger, linear, lanceolate, or ligulate, with or without shoulders, margins distal to the middle entire, serrulate, serrate, or spinose, apex acuminate; costate or ecostate; laminal cells lax and transparent, long-rhomboidal to rectangular, in some species becoming denser distally, smooth, papillose by projecting distal ends, or spinose. Specialized asexual reproduction by fragments and rarely by thick-walled elongate, swollen protonematal segments, commonly brown, and persisting on or in the soil. Sexual condition autoicous, dioicous, or synoicous. Perigonia arising from protonemata, from rhizoids, or just proximal to the perichaetium; small, bud-like with ecostate leaves of lax areolation, broadly triangular to broadly ovate. Perichaetium consisting of 1–3 most distal leaves on the stem, typically the largest and best developed. Vaginula conspicuous. Sporophytes 1–3 per perichaetium with immersed to emerging capsules. Seta virtually absent or very short. Capsule globose or ovoid, without or with an apiculus, cleistocarpous or opening along an indistinct or distinct ring of cells near the equator; exothecium of 1–2 layers of lax and thin-walled cells; stomates absent or superficial with two guard cells. Calyptra persistent, mitrate, and minute, or fugacious, mitrate or cucullate, and irregularly lobed or torn at the base, covering up to 2/3 of the capsule. Spores appearing reniform, globose, or variously angled, 20–120 µm, ranging from barely papillose to coarsely warty, the elaboration often correlating with degree of maturity, usually bearing small remnants of a hyaline membrane, orange, red, brown, or black.

<==Ephemeraceae
    |--Nanomitriopsis Cardot 1909SK02
    |    `--N. longifolia Cardot 1909SK02
    |--Micromitrium Austin 1870S04
    |    `--M. tenerum (Bruch & Schimp.) Crosby 1968S04 [=Ephemerum tenerumD24, Nanomitrium tenerumD24, Phascum tenerumD24]
    `--Ephemerum Hampe 1837 (nom. cons.)SK02
         |--E. capense Müll.Hal. 1888SK02
         |--E. cohaerens (Hedw.) Hampe 1837S04 (see below for synonymy)
         |--E. cristatum (Hooker & Wilson) Müll.Hal. 1847 [=Phascum cristatum; incl. E. grosseciliatum Müll.Hal. 1898]SK02
         |--E. fimbriatum Müll.Hal. 1872SK02
         |--E. furcatum Stone 1996SK02
         |--E. minutissimum Lindb. 1874 [=E. serratum var. minutissimum]S04
         |--E. recurvifolium (Dicks.) Boulay 1872SK02 [=Ephemerella recurvifoliaD24, Phascum recurvifoliumD24]
         |--E. rehmannii (Müll.Hal.) Broth. 1924SK02
         |--E. serratum (Hedw.) Hampe 1837S04 [=Phascum serratumD24]
         |    |--E. s. var. serratumD24
         |    |--E. s. var. angustifolium (Bruch & Schimp.) Bruch & Schimp. in Bruch, Schimp. & Gümbel 1849OZB-O03
         |    |--E. s. var. praecox Walther & Molendo 1868 [incl. E. intermedium]S04
         |    `--E. s. var. rutheanum (Schimp.) Jur. 1882 (see below for synonymy)OZB-O03
         |--E. sessile (Bruch) Müll. Hal. 1848S04 (see below for synonymy)
         |    |--E. s. var. sessileD24
         |    `--E. s. var. brevifoliumD24
         |--E. spinulosum Bruch & Schimp. ex Schimp. 1860S04
         `--E. stellatum Philib. 1879S04

Ephemerum cohaerens (Hedw.) Hampe 1837^S04 [=Phascum cohaerens^D24; incl. Ephemerella flowtowiana^OZB-O03, Ephemerum cohaerens var. flotowianum^OZB-O03]

Ephemerum serratum var. rutheanum (Schimp.) Jur. 1882 [incl. E. cohaerens var. longifolium, E. serratum var. longifolium]^OZB-O03

Ephemerum sessile (Bruch) Müll. Hal. 1848^S04 [=Ephemerella sessilis^S04, Phascum sessile^D24; incl. Ephemerum stenophyllum^D24]

*Type species of generic name indicated

References

Bryan, V. S. 2007. Ephemeraceae. In: Flora of North America Editorial Committee (eds) Flora of North America North of Mexico vol. 27 pp. 646–653. New York and Oxford.

[D24] Dixon, H. N. 1924. The Student’s Handbook of British Mosses 3^rd ed. V. V. Sumfield: Eastbourne.

[OZB-O03] Ochyra, R., J. Żarnowiec & H. Bednarek-Ochyra. 2003. Census Catalogue of Polish Mosses. Institute of Botany, Polish Academy of Sciences: Cracow.

[S04] Smith, A. J. E. 2004. The Moss Flora of Britain and Ireland 2^nd ed. Cambridge University Press.

[SK02] Streimann, H., & N. Klazenga. 2002. Catalogue of Australian Mosses. Flora of Australia Supplementary Series 17. Australian Biological Resources Study: Canberra.