I have a soft spot for navelwort, one of the more unusual wild plants of the British Isles that is especially abundant in Ireland. It is an odd plant in lots of ways. The most obvious feature, seen all year round until it blooms, from May till about August, is those weird, fleshy leaves. They are round with scalloped edges and held like ‘blown open’ umbrellas with the stem attached to the centre of the leaf. Where the stem meets the leaf there is a central depression in the leaf, and it does not take much imagination to see this is like a belly button (an ‘inny’ not an ‘outy’) and this is the origin of the common name of navelwort or the bontanical name Umbilicus. The full name is Umbilicus rupestris and rupestris means ‘wall’. Old walls and rocks is where you are most likely to find it though it will grow in other, perfectly drained places too (such as the trunks of tree below). The Irish name is Cornán caisil and it is also called wall pennywort.
You would hardly guess from the shape of the leaves but it is in the crassula family but the succulent leaves and the five-petalled flowers, though here united into a greenish white bell, may give the game away.
Although this is usually a plant found on walls it can grow in rocky soil too and I found an abundance of it at Mount Congreve last weekend.
It is perennial but the leaves often look miserable at flowering time, especially in a dry season such as this. It usually grows to about 25cm when in bloom but starved plants will be much smaller while those in fertile habitats will b much bigger and some of these are about 60cm high. Although the flowers are not in any way showy there are so many crowded onto the spikes that they make a rather ethereal display and if ever there was a fairy flower this is it.
It is able to survive in the merest scrap of soil and seeds freely.