Viability and germination of herbaceous perennial species native to southern Alberta grasslands

The viability and germination of seed lots of 41 herbaceous perennial species native to southern Alberta grasslands were examined. The practical value of tetrazolium (TTC) and x-ray photography in screening seed lots for viability was evaluated. Although a reliable, rapid test for a few taxa, TTC often gave erratic results which were inconsistent with germination percentages and/or the physical condition of excised embryos. X-rays were useful for determining the percentage of full seeds in samples of species having large seeds, but had insufficient resolving power for samples of smaller seeds. Stratification improved germination in most species of Compositae, all three species of the Scrophulariaceae, and both species of Cactaceae.