Class
Family
Subfamily
Classification
Subordinate Taxa
Nomenclature
Scientific Name:
Pseudocrossidium R.S.Williams, Bull. Torrey Bot. Club 42: 396 (1915)
Type Taxon:
Pseudocrossidium chilense R.S.Williams
Etymology:
Description
The following generic description is modified from Zander (1993).
Plants yellow-green to brown, forming turves or tufts, on soil or rock. Stems simple or branched, in cross-section rounded-pentagonal, with central strand and sclerodermis usually present. Leaves spreading to erect-spreading (in N.Z. species) when moist, twisted when dry, ovate or ligulate to lanceolate or narrowly triangular, obtuse to acuminate; margins recurved to revolute; upper laminal cells clear in outline to obscure; subquadrate to hexagonal, often oblate, firm-walled, pluripapillose, with complex papillae; upper marginal cells not differentiated; lower laminal cells differentiated in a large or small zone, rectangular, smooth. Costa excurrent as an arista, or a short or long smooth to denticulate hair-point, in cross-section with 1 or 2 stereid bands. Axillary hairs of 5–10 cells, colourless throughout. Brood bodies occasionally present (not known in N.Z. species). Laminal KOH colour reaction yellow to orange.
Dioicous. Perichaetia terminal, with inner leaves little differentiated or highly differentiated, enlarged, and often convolute-sheathing. Perigonia bulbiform. Setae elongate. Capsules ellipsoid to cylindric, occasionally curved, with a persistent annulus of 2–4 rows of vesiculose cells. Operculum short- to long-conic or conic-rostrate. Peristome twisted or occasionally straight, with basal cylinder low (in N.Z. species) or absent. Spores 8–15 μm, smooth to weakly papillose.
Taxonomy
Some 21 species of Pseudocrossidium are accepted worldwide (Cano et al. 2022), with the highest concentration found in South America. The two species found in N.Z. have historically been placed in Barbula(e.g., Sainsbury 1955; Scott & Stone 1976; Magill 1981), but in this account the treatments of Zander (1993, 2006), Zander et al. (2007) and Cano et al. (2016, 2022) are followed
Key
| 1 | Leaves 2.5–4.5 mm in length; costa of upper leaves long excurrent in a weakly flexuose hair-point; margins plane at lamina apex | P. crinitum |
| 1' | Leaves c. 1 mm in length; costa of upper leaves shortly excurrent in a stiff arista; margins revolute at lamina apex | P. hornschuchianum |
Biostatus
Indigenous (Non-endemic)
| Category | Number |
|---|---|
| Indigenous (Non-endemic) | 1 |
| Exotic: Fully Naturalised | 1 |
| Total | 2 |
Bibliography
Beever, J.E. 2024: Pottiaceae subfamily Barbuloideae. In: Heenan, P.B. (ed.) Flora of New Zealand — Mosses. Fascicle 50. Manaaki Whenua Press, Lincoln.
Cano, M.J.; Jiménez, J.A.; Gallego, M.T.; Guerra, J. 2022: A molecular approach to the phylogeny of the moss genus Pseudocrossidium (Pottiaceae, Bryopsida) and its taxonomic implications. Journal of Systematics and Evolution 60(4): 914–931.
Cano, M.J.; Jiménez, J.F.; Alonso, M.; Jiménez, J.A. 2016: Untangling Pseudocrossidium crinitum s.l. (Pottiaceae, Bryophyta) through molecular and morphometric analysis. Nova Hedwigia 102(1-2): 89–106.
Goffinet, B.; Buck, W.R.; Shaw, A.J. 2009: Morphology, anatomy, and classification of the Bryophyta. In: Goffinet, B.; Shaw, A.J. (ed.) Bryophyte Biology. Edition 2. Cambridge University Press, Cambridge. 55–138.
Magill, R.E. 1981: Bryophyta, Part 1 Mosses, Fascicle 1, Sphagnaceae–Grimmiaceae. Leistner, O.A. (ed.) Flora of Southern Africa. Botanical Research Institute, Pretoria.
Sainsbury, G.O.K. 1955: A handbook of the New Zealand mosses. Bulletin of the Royal Society of New Zealand 5: 1–490.
Scott, G.A.M.; Stone, I.G. 1976: The Mosses of Southern Australia. Academic Press, London.
Williams, R.S. 1915: Mosses from the west coast of South America. Bulletin of the Torrey Botanical Club 42: 393–404.
Zander, R.H. 1993: Genera of the Pottiaceae: mosses of harsh environments. Bulletin of the Buffalo Society of Natural Sciences 32: i–vi, 1–378.
Zander, R.H. 2006: The Pottiaceae s. str. as an evolutionary Lazarus taxon. Journal of the Hattori Botanical Laboratory: 581–602.
Zander, R.H.; Eckel, P.M.; Mishler, B.D.; Delgadillo-M., C.; Magill, R.E. 2007: Pottiaceae Schimper. In: Flora of North America Editorial Committee (ed.) Flora of North America North of Mexico. Vol. 27 Bryophyta, Part 1. Oxford University Press, New York and Oxford. 476–642.
