Umbilicus   Fischer (1809)

The genus Umbilicus includes about 12 species of small plants with flat, round, succulent leaves, mostly with a small tuber or rhyzome. Plants in this genus have leaves with a navel-like depression over the site of stem attachment on the underside, with leaf veins radiating from this point. The inflorescence is a long stem bearing many drooping tubular or bell-shaped yellow, cream or greenish flowers. About 80 species formerly residing in this genus have been moved to genera such as Cotyledon, and Chiastophyllum and Rosularia.
Umbilicus oppositifolius from the the Caucasus has Saxifrage-like leaves and has been moved to the monotypic genus Chiastophyllum.
 
Umillicus rupestris (Syn. Cotyledon umbilicus) (Pennywort, Birthwort) is a common plant native to the West of Great Britain and Europe into Asia, Arabia and South into the mountains of Africa. It is typically found in crevices on walls and rocks, but may also occur in sparse grassland. The leaves exhibit the navel-like form for which the genus is named, with the stem attached to the depressed centre of the leaf. It is easy to cultivate, but grows where it will and dislikes being transplanted. It is perennial but generally monocarpic. The rounded leaves sometimes die back in winter to the small tuber.
 
This species can be raised in a pot as a handsome flowering plant. Transplant when very small and avoid disturbing the roots by moving an intact clump of soil or sprinkle seed from a dead flower spike over a suitable pot and hope for the best. The inflorescence is a 10 in stem bearing many drooping tubular greenish-white flowers. As the flowers open the leafy part of the plant begins to senesce.