Reflexed stonecrop (Sedum rupestre)

Dear Readers, I have often remarked on the variety of stonecrops that ‘crop up’ (apologies) in St Pancras and Islington Cemetery, so I thought that this week we could have a look at these remarkable plants. All of them grow only on particular graves, normally those that have been covered with gravel. I doubt that they were planted deliberately, and they give a strangely coastal feeling to parts of the cemetery.

All of the stonecrops are members of the Crassulaceae family. They are succulents, and so can thrive on very thin, desiccated soil. All stonecrops operate using a form of photosynthesis called ‘Crassulacean Acid Metabolism’ or CAM for short. Basically, the plant keeps the little holes in its leaves, called stomata, closed during the day so that it doesn’t lose water. Then at night, it opens the stomata so that it can collect the carbon dioxide that it needs for photosynthesis, and stores the gas so that it can continue to operate during the day. This is thought to be an adaptation to hot, dry climates where the plant would not otherwise be able to survive.

I’ve noticed three species of stonecrop in the cemetery, though there may be many more.

Firstly, we have reflexed stonecrop (Sedum rupestre/reflexum). This plant was probably introduced to the UK in the 17th century as a salad crop – those tiny leaves are said to have a bitter, astringent taste. It was recorded in the wild by 1666. In the USA the plant is known as Jenny’s stonecrop. As with all sedums, the delight is in the detail – I love the circlets of golden flowers, and the redness of the stems. No wonder people use these plants on their green roofs – they are superbly adapted to the dryness and thinness of the soil.

The white stonecrop (Sedum album) is just going over now, but at its height it covered some graves in a sea-spume of tiny flowers. This is probably an ancient introduction, or archaeophyte, meaning a plant that was growing in the wild in the UK before 1500 BCE. If you look closely at the photo, you can see how the plant is growing amidst a collection of green frosted-glass pebbles, an environment in which no other plants seem to be able to survive, so the stonecrop has the whole grave to itself.

White stonecrop (Sedum album)

The third stonecrop that I’ve spotted is Caucasian or two-rowed stonecrop (Sedum spurium). This is a much more recent introduction than the other two species, and has undoubtedly hopped over the wall from a garden somewhere, or may even have been deliberately planted on the grave. It comes from Eastern Europe, as its name suggests, and there are a number of cultivars on offer.

Caucasian stonecrop (Sedum spurium)

All the stonecrops seem to be very attractive to hoverflies, and the fact that they flower in the sunniest spots can only help. I wasn’t sure if any insects ate the leaves but a quick look at my ‘Field Guide to the Caterpillars of Great Britain and Ireland’ revealed that the caterpillars of the Mullein Wave (Scopula marginepunctata), Magpie (Abraxas grossulatiata), Scotch Annulet (Gnophos obfuscata) and the Sword Grass (Xylena exsoleta) have all been found munching on various species of stonecrop, including the more ornamental ones, so keep your eyes open if you have some in your garden. The caterpillar of the Sword Grass looks especially spectacular.

Mullein Wave moth (Photo One)

Magpie moth (Photo Two)

Sword-grass caterpillar (Photo Three)

And finally, as often happens when you use a word over and over again in a piece of writing, I find myself thinking about the word ‘stonecrop’. It has its origins in Old English, but it can, of course, be read in two ways. It might be that, given the fact that some varieties of sedum are edible (and reflexed stonecrop might actually have been brought here as a herb), the word refers to a ‘crop that is grown amidst stones’. However, what also springs to mind is a crop of stones, a failed harvest, a hard and hungry time. Maybe stonecrop was also sometimes used as a famine food?

And so a poem, by Robinson Jeffers, an American poet from California who died in 1962. I like the way that this poem celebrates the way that nature is reclaiming the industrial site with its ‘rose-tipped stonecrop’. See what you think.

Bixby’s Landing by Robinson Jeffers

They burned lime on the hill and dropped it down
here in an iron car
On a long cable; here the ships warped in
And took their loads from the engine, the water
is deep to the cliff. The car
Hangs half way over in the gape of the gorge,
Stationed like a north star above the peaks of
the redwoods, iron perch
For the little red hawks when they cease from
hovering
When they’ve struck prey; the spider’s fling of a
cable rust-glued to the pulleys.
The laborers are gone, but what a good multitude
Is here in return: the rich-lichened rock, the
rose-tipped stone-crop, the constant
Ocean’s voices, the cloud-lighted space.
The kilns are cold on the hill but here in the
rust of the broken boiler
Quick lizards lighten, and a rattle-snake flows
Down the cracked masonry, over the crumbled
fire-brick. In the rotting timbers
And roofless platforms all the free companies
Of windy grasses have root and make seed; wild
buckwheat blooms in the fat
Weather-slacked lime from the bursted barrels.
Two duckhawks darting in the sky of their cliff-hung
nest are the voice of the headland.
Wine-hearted solitude, our mother the wilderness,
Men’s failures are often as beautiful as men’s
triumphs, but your returnings
Are even more precious than your first presence.

Photo Credits

Photo One by Ben Sale from UK, CC BY 2.0 , via Wikimedia Commons

Photo Two by Ben Sale from UK, CC BY 2.0 <https://creativecommons.org/licenses/by/2.0>, via Wikimedia Commons

Photo Three by Hectonichus, CC BY-SA 3.0 <https://creativecommons.org/licenses/by-sa/3.0>, via Wikimedia Commons