Pellionia repens is an easy to grow plant with forest green oval crenated leaves are accented with a silvery overlay and purple/brown with red veins on trialing succulent stems. Trailing Watermelon Begonia is the common name. The plant grows like a vine and will shingle up tank walls if damp or humid enough. For the initial planting, simply lay down a clump of plants where you would like it to spread and keep wet.