Convallaria is a rhizomatous genus considered by some to have only one species (Convallaria majalis) but in 2020 Plants of the World lists three, all found in different parts of the world. There is no agreement about which family to assign to it. It was originally considered to belong to Liliaceae, then moved to the family Convallariaceae. This latter family is not recognized by the Angiosperm Phylogeny Group II which redirects the genera once assigned to it to a broader Asparagaceae or a narrower Ruscaceae. This species is often found in lists of bulbs that can be grown in the shade. It is reported that potted plants are easily forced into flower after vernalization at 0 to 2 °C for 12 to 14 weeks.
Convallaria keiskei Miq. has a native range from Siberia to Japan were it grows in forests, shaded ravines, and woodland areas. It is similar to the European species but has smaller foliage of thinner texture and may be smaller overall.
Convallaria majalis L. is commonly called Lily of the Valley. This species is found in woods, scrub, and meadows with a native range of Europe to Caucasus. It is the most commonly grown species. It varies widely depending on its origin. It bears sweetly scented white bell-shaped flowers on terminal racemes in the spring. The Latin name breaks down to 'of the valley' and 'May', which links with another common name "May lily". First two photos taken April 2007 by Jay Yourch. Remaining photos by David Pilling show a ripening fruit, shoots and flower details.
Photographs of seed. Photo 3 shows the same seed as photo 2, a couple of months later, apparently the seed has formed a bud and is waiting for another Winter before starting to grow. Confirmation of that is provided in the last photo which shows the seedlings the next year.
Photos below show forms that are different. The first one shows unusual variegated leaves and was photographed July 2007 at Plant Delights Nursery by Jay Yourch. The second photo taken by Giorgio Pozzi May 2008 is of a variety with pink flowers. Flowers are the same size as the white form and also smell the same. The third photo from Hans Joschko also is of a plant with pink flowers.
Convallaria pseudomajalis W.Bartram, syn. Convallaria majuscula Greene, syn. Convallaria montana Fernald, is native to East Central U.S.A. (Alleghey Mountains, Cherokis Mountains). It is larger and more erect and forms open colonies on acid mountain slopes and in sandy woods where it grows in summer dry soils under oaks. Photos from iNaturalist taken by Ann Walter-Fromson and flowering in May in North Carolina and shared under a CC BY-NC license.