Brachytheciastrum dieckei (Röll) Ignatov & Huttunen

Hugonnot, Vincent, 2019, New records for the bryophyte flora of Corsica, Cryptogamie, Bryologie 20 (14), pp. 153-158 : 155-156

Brachytheciastrum dieckei (Röll) Ignatov & Huttunen

SPECIMEN EXAMINED. — France. Corse-du-Sud, Quenza, plateau de Cusciunu, on rock outcrops, in 7.V.2017, 1540 m, V. Hugonnot s.n.

Remarks

It was observed on granitic rock outcrops in Alnetum suaveolentis Litard. & Malcuit, 1926 vegetation but this does not necessarily reflect a particular preference for this type of habitat. The species seems rather unspecialized as regards its ecological preferences as it is recorded to grow on alkaline and acidic grounds, rocks in forests or scrublands, or as an epiphyte on trees and bushes, from 550-3250 m a.s.l. ( Orgaz et al. 2013). This should be confirmed by additional field observations. The species is fully fertile in Corsica, with abundant production of spore capsules. It is very likely that B. dieckei was confused with the very common B. velutinum (Hedw.) Ignatov & Huttunen.

Brachytheciastrum dieckei is a Mediterranean species, known from Africa, Asia and Europe ( Orgaz et al. 2013). It is recorded from the Canary Islands in Macaronesia; Albania, Croatia, Cyprus, France, Greece, Italy, Montenegro, Portugal and Spain in southern Europe; Morocco in northern Africa; and Israel, Lebanon and Turkey in south-western Asia ( Orgaz et al. 2010, 2013; Ros et al. 2013; Hodgetts 2015). In France it was recorded from Hautes-Alpes Department ( Orgaz et al. 2013) and is most probably more widespread in Mediterranean France.

This species is characterized by a set of characters of difficult interpretation without experience; the leaves are shorter and more ovate than that of B. velutinum , margins are more commonly distinctly recurved, alar group is much more apparent with marginal cells ascending up margin, the laminal cells are dorsally prorate and the seta is rough ( Orgaz et al. 2013). The abaxial proration of leaf-cells is subject to variation and is not always easy to observe in the Corsican specimens. Corsican Brachytheciastrum specimens housed in herbaria should be re-examined taking into account the revision of Orgaz et al. (2013).