Cyclodictyon laetevirens

Range & Status

Occurs in W. Europe in Portugal, Spain and the British Isles; also Azores, Madeira and tropical Africa. In the British Isles it is known mainly in W. and especially SW. Ireland, with isolated localities in Jura, Islay and W. Cornwall.

Regional Distribution

Discovered in 1840 in Mousehole Cave; also occurred in another cave between Mousehole and Lamorna, but extirpated there before 1844 (Greenwood, 1844; Paton, 1969). Rediscovered south of Mousehole in 1996.

Habitat & Ecology

Recorded on deeply-shaded, wet rocks in sea-caves. Elsewhere, it typically occurs on acidic or mildly basic, deeply-shaded rocks in dripping caves, recesses by waterfalls and holes in the sides of ravines (Birks in Hill et al ., 1994). Capsules are rarely produced (recorded in Cornwall), maturing in late summer and autumn.

Threats

Deliberate collecting of specimens by bryologists may have caused or contributed to its extinction at some sites. Greenwood (1844) and Marquand (1890) record that it was wilfully destroyed in one cave prior to 1844.

Conservation

C. laetevirens is one of the rare bryophytes to receive special protection under Schedule 8 of the Wildlife and Countryside Act 1981. Listed as Endangered in the UK Red-list (Church et al ., 2001). This species is listed on the UK BAP Priority Species list (2007).