Seed germination of endemic species from Kerguelen phytogeographic zone

Seeds of six endemic species and two circumpolar species were collected from several sites on Kerguelen and tested for germination between 5 and 25°C on thermogradient bars. Pringlea antiscorbutica and Colobanthus kerguelensis had a near 100% viability with an initial germination temperature of ca. 24°C. Colobanthus attained nearly 100% viability from 5 to 25°C whereas Pringlea germination declined markedly below 20°C. In Poa kerguelensis and P. cookii germination was poor and varied between sites. The three Ranunculus spp. showed various degrees of dormancy. In Lyallia kerguelensis, although the seed appeared mature, a variety of treatments could only partly release an apparently deep dormancy. These data are discussed with respect to field observations on reproduction from seed.