Primi dati sull’ecologia della germinazione dei semi di Halimium halimifolium (L.) Willk. subsp. halimifolium (Cistaceae) al limite orientale della sua area di distribuzione

First contribution to seed ecology of Halimium halimifolium (L.) Willk. subsp. halimifolium (Cistaceae) at the Eastern limit of its distribution area. - According to literature, the variability in the seed germination process among different populations is well known. The aim of the present work was to compare the seed germination behaviour of Halimium halimifolium (L.) Willk. subsp. halimifolium population coming from the Apulia region (Italy), which correspond to the Eastern limit of the species’s distribution area, with the behaviour of other populations of the same subspecies described in literature. The results obtained have highlighted the presence of considerable differences for the seed behaviour during the germination process when comparing with Spanish populations, coming from the Western side of the species’s distribution area. The heat tolerance (up to 150 °C for 7,5 minutes) that characterizes the Spanish populations was not verified in the studied population. In fact, the results obtained for the Apulian population showed that at temperature of 80 °C the differences are not statistically significant on the germination percentage; however, when the temperature reaches 100 °C there is an evident decrease in the germination performance. Nevertheless, further study is needed to affirm with certainty that the population analyzed is not a typical active pyrophite.