A genus of about 23–45 species of lily-like plants native to northeast Asia. They were once classified in the Liliaceae but are now included in the Agavaceae by the Angiosperm Phylogeny Group, although some taxonomists place the Hostas in their own family: Hostaceae. The scientific name is also used as the common name; in the past they were also sometimes called the Corfu Lily, the Day Lily, or the Plantain lily, but these terms are now obsolete.

Hostas are herbaceous perennial plants, growing from rhizomes or stolons, with broad lanceolate or ovate leaves varying widely in size by species from 1–15 in (3–40 cm) long and 0.75–12 in (2–30 cm) broad. Variation among the numerous cultivars is even greater.

Leaf color in wild species is typically green, although some species (e.g., H. sieboldiana) are known for a glaucous waxy leaf coating that gives a blue appearance to the leaf. Some species have a glaucous white coating covering the underside of the leaves. Natural mutations of native species are known with yellow-green ("gold") colored leaves or with leaf variegation (either white/cream or yellowish edges or centers). Variegated plants very often give rise to "sports" that are the result of the reshuffling of cell layers during bud formation, producing foliage with mixed pigment sections.

The flowers are produced on erect scapes up to 31 in (80 cm) tall that end in terminal racemes. The individual flowers are usually pendulous, 0.75–2 in (2–5 cm) long, with six tepals, white, lavender, or violet in color and usually scentless. The only strongly fragrant species is Hosta plantaginea; it is also unusual in that the flowers open in the evening and close by morning.

from: Wikipedia