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 peltate leaves with a navel-like depression over the site of stem attachment on the underside, with leaf veins radiating from this point. Members of this genus are widely distributed from Great Britain to Asia and Africa.
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, Chiastophyllum and Rosularia.
Umbilicus oppositifolius from the the Caucasus has Saxifrage-like leaves and may also be seen in the
monotypic genus Chiastophyllum.
Umbilicus oppositifolius Ledebour 1843 Syn. Chiastophyllum oppositifolium Stapf ex A. Berger 1930
This plant differs from all other members of Umbilicus in not having a tuberous root. The leaves also differ being
saxifrage-like, rather than peltate as are all other members of Umbilicus. The branching inflorescence has a basally-reddened stem, usually drooping over, with several pairs of smaller leaves along its length and many small golden-yellow flowers towards the ends of each branch.
Native to the Causacus (Georgia), quite hardy and suitable for the rock garden. Various selected cultivars are propagated in the horticultural trade including a variegated form.
Umbilicus rupestris Dandy 1948 (Pennywort, Birthwort) Syn. Cotyledon umbilicus
This common plant is 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 by rubbing dead flowers from from an old, brown flower spike over a suitable pot and hope for the best. I find this to be a very successful method of propagation. 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.