Leskeaceae

Claopodium assurgens, from here.

Belongs within: Hypnales.

The Leskeaceae are a family of mosses found worldwide, traditionally distinguished by the possession of reduced peristomes and short laminal cells. Recently, the family as previously recognised was identified as polyphyletic by García-Avila et al. (2009), with the type genus Leskea nested within the Thuidiaceae. Leskea species are autoicous mosses with relatively few paraphyllia and erect capsules.

Characters (from Watson & Dallwitz): Gametophyte: Pleurocarpous; not dendroid; mostly forming patches, or forming wefts. Primary stems procumbent (the branches erect or procumbent). Shoots not complanate. Paraphyllia present (sparse or numerous), or absent. Pseudoparaphyllia absent. Stems not tomentose. The leaves of main stems and branches similar in form; ovate to lanceolate (concave); spiral; (sub-)secund (or the tips turned to one side, when moist), or not secund; double-nerved, or single-nerved. The leaf nerves not extending beyond the middle of the leaf, or extending beyond the middle of the leaf, but not to the tip. Leaf blade apices obtuse, or pointed; apically rounded, or apically acute, or acuminate. Leaf blade margins flat, or revolute or recurved; entire, or denticulate. Leaf blades not conspicuously bordered. The basal leaf cells more or less isodiametric to longitudinally much elongated; quadrate, or rectangular, or rounded, or rhomboidal to linear; papillose, or smooth. The walls of basal leaf cells thin, or thick; straight. The angular cells clearly differentiated, or not well differentiated. The mid-leaf cells more or less isodiametric to somewhat longitudinally elongated, or longitudinally much elongated; quadrate, or rectangular, or hexagonal, or rounded, or rhomboidal to vermicular; papillose, or smooth. The walls of the mid-leaf cells thin, or thick; straight. Plants monoecious, or dioecious; when monoecious, autoecious. Sporophyte: Capsules exserted; erect to inclined; symmetrical, or symmetrical to asymmetrical; straight, or curved; sub-cylindric to ovoid; smooth; with an annulus, or without an annulus. Calyptra symmetrical; splitting down one side. Capsules with a peristome. The peristome double. The peristome teeth joined basally to form a membranous ring, or not basally joined; not grouped; not deeply cleft; thin, membranous, and transversely barred; exteriorly with a fine longitudinal dividing line between the transverse bars. The inner peristome reduced to rudimentary; about equalling the outer to exceeding the outer; with a basal membranous ring (this short); with elongated “processes”; without cilia (or rudimentary). The operculum conical to rostrate. Setae long; straight.

<==Leskeaceae
    |--Claopodium (Lesq. & Jam.) Renauld & Cardot 1893 SK02
    |    `--C. assurgens (Sull. & Lesq.) Cardot 1911 SK02
    |--Pseudoleskeopsis Broth. 1907 SK02
    |    `--P. imbricata (Hooker & Wilson) Thér. 1929 (see below for synonymy) SK02
    |--Lindbergia N02
    |    |--L. koelzii N02
    |    `--L. longinervis N02
    |--Myurella D24
    |    |--M. apiculata [=Isothecium apiculatum; incl. M. tenerrima] D24
    |    |--M. careyana D24
    |    `--M. julacea [=Hypnum julaceum] D24
    |         |--M. j. var. julacea D24
    |         `--M. j. var. scabrifolia D24
    |--Heterocladium D24
    |    |--H. dimorphum [=Hypnum dimorphum; incl. He. squarrosulum] D24
    |    |--H. heteropterum (see below for synonymy) D24
    |    |    |--H. h. var. heteropterum D24
    |    |    `--H. h. var. fallax D24
    |    `--H. macounii D24
    |--Leskea VH02
    |    |--L. complanata SK02 [=Hypnum complanatum D24, Neckera complanata SK02]
    |    |--L. fuegiana D03b
    |    |--L. gracilescens VH02
    |    |--L. nervosa [=Pterogonium nervosum] D24
    |    `--L. polycarpa D24
    |         |--L. p. var. polycarpa D24
    |         `--L. p. var. paludosa D24
    `--Pseudoleskea D24
         |--P. atrovirens [incl. H. filamentosum, Lesquereuxia filamentosa] D24
         |--P. catenulata [=Hypnum catenulatum, Leskea catenulata] D24
         |--P. fuegiana D03a
         |--P. incurvata N02
         |--P. laevifolia N02
         |--P. patens [=Leskea patens; incl. Lesquereuxia atrovirens] D24
         |--P. rigescens [incl. P. stenophylla] D24
         `--P. striata [=Lescuraea striata, Pterogonium striatum] D24
              |--P. s. var. striata D24
              `--P. s. var. saxicola [=Lesquereuxia saxicola] D24

Nomen nudum: Leskea splendidula Hampe 1880 [=Rhaphidorrhynchum splendidulum Mitt. 1882, Rhaphidostegium splendidulum Paris 1897] SK02

Heterocladium heteropterum [=Pterogonium heteropterum; incl. H. heteropterum var. flaccidum, H. heteropteroides, H.wulfsbergii] D24

Pseudoleskeopsis imbricata (Hooker & Wilson) Thér. 1929 [=Leskea imbricata, Cryphaea imbricata, Pseudoleskea imbricata; incl. Leskea calochlora, P. calochlora] SK02

*Type species of generic name indicated

REFERENCES

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

[D03a] Dusén, P. 1903. The vegetation of western Patagonia. In: Scott, W. B. (ed.) Reports of the Princeton University Expeditions to Patagonia, 1896–1899, vol. 8. Botany pp. 1–34. The University: Princeton (New Jersey).

[D03b] Dusén, P. 1903b. Patagonian and Fuegian mosses. In: Scott, W. B. (ed.) Reports of the Princeton University Expeditions to Patagonia, 1896–1899 vol. 8. Botany pp. 63–126. The University: Princeton (New Jersey).

García-Avila, D., E. De Luna & A. E. Newton. 2009. Phylogenetic relationships of the Thuidiaceae and the non-monophyly of the Thuidiaceae and the Leskeaceae based on rbcL, rps4 and the rps4-trnS intergenic spacer. Bryologist 112 (1): 80-93.

[N02] Negi, H. R. 2002. Abundance and diversity of moss communities of Chopta-Tunganath in the Garhwal Himalaya. Journal of the Bombay Natural History Society 99 (3): 418–433.

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

[VH02] Vanderpoorten, A., L. Hedenäs, C. J. Cox & A. J. Shaw. 2002. Phylogeny and morphological evolution of the Amblystegiaceae (Bryopsida). Molecular Phylogenetics and Evolution 23 (1): 1–21.

Last updated: 7 January 2018.