Fossombronia angulosa
Fossombronia angulosa (Dicks.) Raddi
Fossombroniaceae
Conservation status. Endangered [EN B2ab(iii)c(ii)].
Morphology and biology. Annual (rarely short-lived perennial) liverwort with differentiated stem and leaves forming small pale to yellow-brown rosettes or mats. Shoots prostrate, irregularly branched, 1–3 cm long and up to 0.6 cm wide, with numerous red-violet rhizoids. Leaves obliquely inserted, oval-quadrate, with characteristic wavy appearance. Unisexual. Spores large, with reticulate surface, forming almost regular hexagons. Does not form gemmae.
Habitats and populations. Grows on bare wet, clayey to sandy soils in shady oak and beech forests. The populations have restricted distribution, low density and variable numbers, related to the yearly dynamics of the climatic conditions.
Distribution in Bulgaria. Strandzha Mts (locality Golyam Draganovski Dol by Slivarovo village, and locality of Kerezovia Dol by Kosti village).
General distribution. Balkan Peninsula, W Europe, Mediterranean islands, Caucasus, N Africa, Macaronesia, W Asia. Oceanic-Mediterranean species.
Threats. Decrease of the air and substrate humidity due to forest thinning, over tramping, and successional changes of plant communities. The species depends on the presence of competition-free substrates and recurrent moderate habitat disturbance.
Conservation measures taken. The populations are within the borders of Strandzha Nature Park and in a site of the European ecological network Natura 2000 in Bulgaria.
Conservation measures needed. To study the dynamics of the numbers and area of the populations, as well as the biology and ecology of the species in Bulgaria; to elucidate the threatening factors and monitor the populations.
References. Petrov 1963.
Author: Rayna Natcheva
