Seligeria calcarea (Hedw.) Br.Eur.
Family: Seligeriaceae
A tiny moss that grows on sheltered surfaces of chalk rock. It does not tolerate full exposure to sunlight or heavy shade.
In brief
Species description
This tiny acrocarpous moss grows on rock as scattered plants or forms diminutive green or olive green turfs, the shoots being up to 2 mm high. The leaves are erect, ovate to ovate-lanceolate or narrowly lanceolate, ending in a rather broad, blunt point composed entirely of nerve tissue. The capsule is ovate to hemispherical, as wide as long, widest at the mouth only when old and empty, with well developed peristome, erect and exserted on a straight seta 1-2 mm long. The spores measure 14-18 μm.
Life cycle
The plants are short-lived perennials arising from a persistent protonema. It is an autoicous species in which capsules are common; gemmae, bulbils and tubers are absent.
Similar species
S. calcarea is distinct from other Seligeria in Ireland in its combination of short, blunt-tipped, entire leaves and peristomate capsules that are not much longer than wide.
How to see this species
S. calcarea can be seen at Whitepark Bay or near Straidkilly Point by very close searching of sheltered chalk rocks.
Current status
Seven records in 1999 resulted from sustained efforts to locate Seligeria spp. during bryophyte surveys in Northern Ireland; almost all of the populations found were small and it was not refound at Benbradagh.
Why is this species a priority in Northern Ireland?
The following Priority Species Criteria apply to S. calcarea:
Threats/Causes of decline
Not known in detail. Most populations of S. calcarea are small and some of them are potentially vulnerable to shading if scrub or saplings become established.
Conservation of this species
Current action
Proposed objectives/actions
What you can do
Careful microscopic study by a skilled bryologist is needed to confirm identification of this species. New sites should be reported to NIEA and the British Bryological Society's Recorder for Mosses (see below).
Further information
Links
British Bryological Society
Literature
Atherton, I., Bosanquet, S. & Lawley, M. (eds) (2010). Mosses and liverworts of Britain and Ireland: a
field guide. Wootton, Northampton: British Bryological Society.
Lockhart, N., Hodgetts, N. & Holyoak, D. (2012). Rare and threatened bryophytes of Ireland. NMNI, Belfast.
Smith, A.J.E. (2006). The moss flora of Britain and Ireland. 2nd ed with corrections (paperback). Cambridge: Cambridge University Press.
Text written by:
David Holyoak