Ramondo-Ostryetum carpinifoliae – a new association from the hop-hornbeam forests of the Sharri Mountains, Kosovo

In Europe, the genus Ramonda is represented with three species: Ramonda nathaliae, Ramonda serbica and Ramonda myconi. The first two are endemic Balkan species that are distributed also in Kosovo. These species grow in limestone as well as serpentine substrates, forming chasmophytic vegetation. The species Ramonda nathaliae is found in Macedonia, Greece, Serbia and in two localities in Kosovo, in the Sharri Mountains (Luboten and Gotovushë). R. nathaliae forms the following plant associations in the serpentines of Macedonia: Asplenio­Ramondetum nathaliae and Scorzonero-Ramondetum nathaliae, and the Achilleo­Ramondetum nathaliae in limestone substrates. Ostrya carpinifolia is charateristic species in Querco pubescentis-Ostryetum carpinifoliae, Ostryo-Fagetum, Querco-Ostryetum carpinifoliae and Corylo colurnae-Ostryetum carpinifoliae. This paper presents plant communities of Ramonda nathaliae and Ostrya carpinifolia in a limestone habitat, where the proposed new plant association named Ramondo­Ostryetum carpinifoliae ass. nova. is described. This plant community belongs to the class Quercetea pubescentis, order Quercetalia pubescenti­petraeae and alliance Fraxino orni­Ostryion. It was found and described on the limestone substrate on Mt. Luboteni (at 960–982 m a.s.l.).

QUANTITATIVE ASSESSMENT OF ANISOCOTYLY IN HABERLEA RHODOPENSIS AND RAMONDA MYCONI

Anisocotyly, the unequal development of cotyledons post germination, is a unique trait observed only in Old World Gesneriaceae (Lamiales). New World Gesneriaceae have isocotylous seedlings. In both Old and New World Gesneriaceae, cotyledons initially grow equally for a short period just after germination. In the New World species, both cotyledons cease their growth at the same time early on, whereas in Old World species one cotyledon continues to expand to become a macrocotyledon while the other withers away. In this study, cotyledon growth was observed in two European Old World Gesneriaceae: Haberlea rhodopensis and Ramonda myconi. The results were compared with those for the typical anisocotylous species Streptocarpus rexii and the typical isocotylous species Corytoplectus speciosus. We found that the cotyledon growth patterns in Haberlea rhodopensis and Ramonda myconi were intermediate between the typical anisocotylous or isocotylous species. Haberlea rhodopensis and Ramonda myconi showed irregular growth patterns, with some plants being slightly anisocotylous but most being isocotylous. The developmental basis for the residual anisocotyly, the extended basal meristem activity in the macrocotyledon, appeared to be identical in the European species to that in the typical Old World Streptocarpus rexii but weakly expressed, rare and terminated early. In conclusion, European Gesneriaceae retain a reduced anisocotylous growth that may be linked to their early plumule development.