SEED-GERMINATION OF ENDEMIC SPECIES FROM KERGUELEN PHYTOGEOGRAPHIC ZONE

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