REPRODUCTION AND DEVELOPMENT OF THE ENDANGERED SEDUM-INTEGRIFOLIUM SSP. LEEDYI (CRASSULACEAE)

Information on reproduction and life history is important for the cons ervation of endangered plants. We investigated rates of flowering, see d set, and germination in populations of the endangered perennial plan t Sedum integrifolium ssp, leedyi. Germination and flowering rates dif fered significantly among populations, but seed set rate did not. We a ssayed 26 plant clusters (81 stems) from four of the five known popula tions For evidence of clonal reproduction using 28 randomly amplified polymorphic DNR (RAPD) markers. Of the 81 stems, 75 had unique genotyp es and three pairs had identical genotypes, suggesting that clonal rep roduction is infrequent. Flowering, seed set, and germination rates we re correlated with our estimates of ratios of effective to actual popu lation sizes (N-c/N), but not with N-e. The single formally protected population may be experiencing inbreeding depression. We grew plants f rom seed to maturity in a greenhouse, with a germination rate of 77% a nd survival of 98% of the germinants at 6 mo, suggesting that this wil l be a viable means of ex situ propagation. Plants flowered 4-6 mo aft er germination and produced mature fruits 1-2 mo later, suggesting tha t they have the potential to sexually reproduce in their first or seco nd season of growth.