Écologie, distribution et morphologie comparées des nivéoles de Nice (Acis nicaeensis) et de Fabre (Acis fabrei), Alliaceae endémiques des Alpes maritimes et et de la Nesque (Vaucluse)

Abstract

Acis nicaeensis and A. fabrei are two endemic geophytes from the Maritime Alps and the Vaucluse (Nesque basin) respectively. The aims of this study are to establish the distinctive morphological characters between the two snowflakes, to examine the chorology and the demography of the populations, in addition with the evaluation of their ecological requirements. Among the most discriminating characters, leaf width, stigma—anther separation, number of internal tepal veins and diameter of the epigynous disk are the most useful. Thirty—six existing populations have been censused for A. nicaeensis occuring in ecological conditions ranging from thermophilous mattoral to xerophilous grasslands with annual or perennial species. The four known populations of A. fabrei are found on rocky grasslands in clearings. The different factors threatening the two snowflakes are discussed.