The flowering plants (angiosperms), also known as Angiospermae or Magnoliophyta, are the most diverse group of land plants, with 416 families, approx. 13,164 known genera and a total of c. 295,383 known species. Like gymnosperms, angiosperms are seed-producing plants; they are distinguished from gymnosperms by characteristics including flowers, endosperm within the seeds, and the production of fruits that contain the seeds. The term "angiosperm" comes from the Greek composite word (angeion, "case" or "casing", and sperma, "seed") meaning "enclosed seeds", after the enclosed condition of the seeds.