Shining Crane’s-bill, Geranium lucidum

Mid spring is the season for Shining Crane’s-bill, Geranium lucidum, an annual that appears early in the year and is in flower from April or early May.

Geranium lucidum has long, brittle, fleshy, hairless stems, which grow up to 35cm (14 inches) long. Its small pink flowers are spaced widely apart, so they complement rather than cover the plant’s distinctive five-lobed glossy green leaves. When the plant is in its prime these leaves really do shine (note 1).

Shining Crane’s-bill can continue flowering right through the summer but in the drier parts of the country it will be past its best by mid to late June. Its stems are often red and the whole plant can turn red as it ages, especially in a dry and sunny place.

Like other species of Geranium (part of the family Geraniaceae) each flower develops into a dry fruit (known as a schizocarp) that splits open (dehisces) to release five dry seeds (achenes) (note 2).

Thriving on Disturbance

Shining Crane’s-bill, Geranium lucidum, is a plant that thrives on disturbance.

When I cycle south-west of Norwich I often head along Potash Lane in Hethel, past the Motor Works (note 3).

The northern part of the lane is blocked off to motor traffic and is lined by hedges. I have seen Bullfinches there on several occasions and it was a great place to pick blackberries and rosehips. Then last summer a Norfolk County Council Highways Team hacked back all the hedges and restored the road to its full width. Their work cut down the roses and brambles and thinned and shortened the hedges, removing the supply of fruit. It can’t have done the Bullfinches any good either.

Recovery will be slow but this spring, at least the verges are green again. The increase in light and disturbance to the ground has caused a population explosion of Shining Crane’s-bill, Geranium lucidum.

A population explosion of Shining Crane’s-bill, Geranium lucidum. Potash Lane, Hethel, 8th May 2023.

My first encounter with Geranium lucidum was at our previous house, where it grew in cracks in the concrete around our next door neighbour’s paths. It moved into our garden and must have hitched a lift in a plant pot to our current garden. Shining Crane’s-bill has now spread along the edges of the flower beds in the shadier part of the garden. It is doing well here – and elsewhere too.

Where the Shining Crane’s-bill grows

Geranium lucidum is native to the British Isles and occurs in most 10 kilometre squares in England and Wales. Its distribution is patchier in Ireland and its distribution thins out in Northern Scotland. The BSBI Plant Atlas records that there has been a marked increase in its abundance and 10km square range since the mid twentieth century and that “this has continued in the last two decades, particularly in south-eastern and eastern England, Scotland and Ireland” (note 4).

Shining Crane’s-bill’s natural home seems to be on calcareous soils: on rock outcrops, limestone pavements and scree. But it has adapted well to man-made habitats: gardens (sometimes deliberately introduced), roadsides, on and at the base of mortared walls, in churchyards, on waste ground and on railway ballast. Nowadays it is spreading into places with more acid soils too, such as Cheshire, where it grows on very acid Cheshire sandstone.

Outside the British Isles, Geranium lucidum is native to many European countries, including Scandinavia and Southern Europe, eastwards into Ukraine and southern Russia but excluding the Netherlands and Poland. Its range continues eastwards through Turkey, Iran and Iraq into Asia as far east as India and down into North Africa (Morocco, Libya, Algeria and Tunisia).

Geranium lucidum was introduced into the United States as a garden plant and now occurs in the states of California, Oregon and Washington. It has also been introduced to Canada (Vancouver Island in British Columbia; detected in 1982) and Australia and New Zealand.

Spreading to America

Shining Crane’s-bill was first detected growing wild in the United States in 1971. Its powers of dispersal are impressive.

In Oregon, it is well established in the Willamette Valley in Oregon, where the climate suits it well and it has been able to invade oak woodlands and open grasslands. Other hotspots include similar habitats and forest clearings in the Portland area, northern California, Bayview State Park in Skagit County, Washington and in southwest Washington.

Shining Crane’s-bill can rapidly dominate the areas it colonises to the exclusion of native herbaceous species. Seeds are scattered explosively and even in still air the seeds can travel up to six metres (20 feet). Humans can help dispersal too: the plant spread from Oregon to Washington in contaminated nursery plants and may also be able to spread as a contaminant of agricultural seed. Seeds persist in the seed bank for more than a year. Geranium lucidum can sometimes be found growing with its relation Herb Robert (known in North America as Roberts Geranium), Geranium robertianum, also introduced from Europe.

An infestation of Geranium lucidum in White Oak woodland at Mt. Pisgah in Oregon, United States. Image: Bruce Newhouse, Bugwood.org.

There is considerable potential for Geranium lucidum to spread further in the United States. The USDA report “Weed Risk Assessment for Geranium lucidum L. (Geraniaceae) – Shining cranesbill” (2013) estimates that about 54 percent of the United States and 4 percent of Canada is suitable for the establishment of Geranium lucidum. At the time of the report it was “currently not a direct threat to threatened and endangered species [but] it could make habitat restoration for rare species difficult”. According to the Oregon Department of Agriculture, Shining Crane’s-bill “[utilises] the abundance of early spring moisture… quickly establishes, dominating sites by smothering other early spring wildflowers and the seedlings of perennial plants. As soils dry, few other plants are able to establish through the receding weed canopy“.

Shining Crane’s-bill is now classed as a noxious weed in parts of the United States, including King County in Washington state. It is prohibited to transport, buy, sell, offer for sale, or to distribute plants or plant parts, seeds in packets, blends or “wildflower mixes” of this species, into or within the state of Washington.

The King County Noxious Weeds website lists ways to control Geranium lucidum. Shoes and vehicles should be cleaned after visiting infested areas and new plantings should be checked, in case the plant has hitchhiked from a nursery. Small patches of Geranium lucidum can be weeded by hand (removing the plant material, rather than composting it) and larger patches by mulching or the use of herbicides.

Don’t Panic!

In its native range Geranium lucidum is more adapted to its environment and is unlikely to be a problem.

If you find Shining Crane’s-bill to be a nuisance in the garden, it is easily pulled up by hand, the earlier in the season the better if you don’t want it to set seed.

I remove some of my plants when they’re growing in the wrong place, but leave most of it to grow.

Edibility

Not much seems to eat Shining Crane’s-bill. The Plants For A Future website says that Geraniums “are rarely if ever troubled by browsing deer or rabbits” and in my garden I find them slug- and snail-proof too.

The plant has no known edible uses for humans. Bug Woman (whose excellent website I found while researching Shining Crane’s-bill) couldn’t find a single recipe and nor can I. Medicinally, it is diuretic and astringent (note 5).

According to the Bug Woman – Adventures In London website Shining Crane’s-bill is used as a foodplant by The Annulet moth (Charissa obscurata), although not exclusively, as the UK Moths website says that the “larvae feed on Heather (Calluna) as well as a range of herbaceous plants“. (The moth is no longer found in Norfolk.)

The caterpillars of the Brown Argus butterfly are becoming more catholic in their tastes. The butterfly used to be restricted to chalk grassland where the caterpillars used Common Rock-rose as a foodplant. In the 1990s, however, the butterfly spread into grasslands away from chalk and started using crane’s-bills (note 6).

Dove’s-foot Crane’s-bill (Geranium molle) and Common Stork’s-bill (Erodium cicutarium) are now used as food plants. The Butterfly Conservation website refers to recent reports of egg-laying on Cut-leaved Crane’s-bill (G. dissectum), Meadow Crane’s-bill (G. pratense), and Hedgerow Crane’s-bill (G. pyrenaicum). Perhaps the Brown Argus has started to use Shining Crane’s-bill too, as suggested by the Wildflower Finder website.

Solitary bees frequently take nectar on species of Geranium in the garden and probably use Shining Crane’s-bill in the wild. I’ll have to keep a look-out. I’ve also seen Wood White butterflies nectaring on Herb Robert; why not Shining Cranesbill too?

Other Crane’s-bills Are Available

There are several other wild species of Geranium in flower at the moment. We have Herb Robert, Geranium robertianum and Dove’s-foot Crane’s-bill, Geranium molle in our garden and I found Cut-leaved Crane’s-bill, Geranium dissectum and Hedgerow Crane’s-bill, Geranium pyrenaicum on my recent bike ride.

I recommend the Wild Flower Society’s at-a-glance guide and, as ever, the Wildflower Finder website and Mike Crewe’s Flora of East Anglia website (which has separate pages for smaller and larger crane’s-bills).

I have already written about some other species of Geranium on this blog: Bloody Crane’s-bill, Geranium sanguineum and blue-flowered garden species such as Purple Crane’s-bill, Geranium x magnificum.

I’ve used the spelling ‘crane’s-bill’ but some writers use the spelling ‘cranesbill’, which is what I learnt from my first flower book, Keble Martin’s Concise British Flora in Colour.

A carpet of Dove’s-foot Crane’s-bill, Geranium molle. New Buckenham, 8th May 2023.

Notes

Note 1 – Geranium lucidum is sometimes known as Shiny Crane’s-bill or Shiny Geranium in the United States.

Lucidum is a form of the Latin adjective lucidus, meaning “clear, bright, shining, full of light”.

The genus name is derived from the Greek géranos or geranós meaning crane, because of resemblance of the fruit capsule to a crane’s head and bill.

Note 2 – The family Geraniaceae is described on pages 364 – 376 of the “New Flora of the British Isles“ by Clive Stace (Fourth Edition, 2019). Stace describes 30 species of Geranium. The family also includes Stork’s-bills (genus Erodium) and a couple of naturalised species of Geranium (genus Pelargonium).

Note 3 – This is where they build Lotus cars.

Note 4 -“Distinguishing between native and alien occurrences is now impossible, so… all records are mapped as if native.”

Note 5 – Its American relative, Geranium carolinianum, apparently tastes bitter but is edible raw or cooked and has medicinal uses as an astringent, salve and styptic and gargle for sore throats.

Note 6 – See “The Butterflies of Britain & Ireland” by Jeremy Thomas and Richard Lewington (British Wildlife Publishing, 2014), page 127.