According Wikipedia, as of 2014, there are over 3,000 varieties registered to the American Hosta Society, encompassing 45 specific species of hostas. Potentially, there are a large number of other varieties that have not yet been registered, but that also exist. Members of the succulent family, hostas are a common shade loving foliage plant used in gardens and as ground cover across the United States and England.
Hostas, also known as plantain lilies, have green heart-shaped leaves. The leaves come in a variety of shades, from yellowish green to bluish green. Some have white on the leaves and others are shiny or waxy. Hosta flowers are either white or purple and bloom each summer. The flowers are typically not fragrant. Hostas come in different sizes, with some miniature varieties of only 4 inches across and larger varieties reaching 6 feet.
Hostas are toxic to dogs, cats and horses due to saponins in the plant. When digested, saponins can cause vomiting and diarrhea. Other animals are not impacted by the saponins, and deer, rabbits, slugs and snails often eat hostas.
Hostas are native to northeast Asia and did not become popular as an ornamental plant until the 1970s. Hostas spread quickly and are easily divided to propagate more plants.