Hydropunctaria orae A. Orange ss. str. (Sequenced).
Specimens presented here have been sequenced (ITS2) and correspond to several lineages of Hydropunctaria orae (Orange 2012), with Pseudendoclonium submarinum as a photobiont. They grow very high in the tidal zone, at the base of the "black belt" of schist cliffs (see picture), in zones where seepage and freshwater streaming occur.
This species is relatively difficult to identify when a specimen is isolated or when sampled for herbarium ; however it is easy to identify in the field with the combination of the following traits :
- Habitat in estuaries or harbours fewly flapped by waves, toward the upper shore and the seacoast fringe, on rocks or at the base of cliffs (rarely on maritime buildings), in practice almost always with Hydropunctaria maura, species dominating this habitat and sometimes with Hydropunctaria oceanica.
- A crustose thallus with a finely rough surface and as if got dirty with some tiny ridges or fine greyish punctuations (specific traits of Hydropunctaria) not or barely cracked and if so only in the center, with a variable colouring depending on moisturising : bottle-green, green-blackish, green, grey-greenish, green-yellowish, etc. and typically "feldgrau" in the field, showing in some abrased places the dull-whitish colouring of the lower side.
- A prothallus dull-whitish to pale-ochrish almost always present.
- Perithecia averagely numerous and usually fewly prominent, with a variable shape but never angular.
NB. Caution in the estuaries because this species is relatively similar to Hydropunctaria rheitrophila that grows in freshwaters, but this latter shows more cheerful green colours, the surface of its thallus is much more "dirty" with blackish spots and its perithecia are smaller.
Orange A. Semi-cryptic marine species of Hydropunctaria (Verrucariaceae, lichenized Ascomycota) from north-west Europe. The Lichenologist 44 (3): 299-320 (2012).