Sulphur Clover, Trifolium ochroleucon

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Sulphur Clover, Trifolium ochroleucon

Sulphur Clover, Trifolium ochroleucon, on a road verge in South Norfolk.

It is always good to find an unexpected plant while out on a walk or cycle ride. Yesterday’s treat was Sulphur Clover, Trifolium ochroleucon, growing on a road verge in South Norfolk. I was on a bike ride with a couple of friends and we were heading home from a lunch stop at Hedenham church when I noticed a large patch of pale yellow clover flowers on the road verge. We stopped and turned back (very easy to do on a bike) and took a closer look.

I say “unexpected” because I have cycled on this road many times, but mostly in winter, so I have never seen Sulphur Clover growing there before. But the habitat is ideal: clay soil and a wide grassy verge, which is managed as a Roadside Nature Reserve. We found further patches of Sulphur Clover on some of the verges as we headed north towards Shotesham.

Sulphur Clover is a clump forming perennial in the Fabaceae (Pea family; formerly Leguminosae) and flowers in June and July. It likes alkaline soils, usually boulder-clay, but can sometimes be found on chalk. It grows on trackways and the borders of woods and in old meadows and pastures but, like the Green-winged Orchid I wrote about earlier this month, it has declined with agricultural “improvement”, whether by ploughing or an excess of nutrients from artificial fertilisers, which encourage coarser grasses to grow at its expense. Road widening has taken its toll and neglect can be damaging too, if grass is not cut or scrub shades it out (note 1).

Sulphur Clover has its stronghold in East Anglia and roadside verges are particularly important for its survival.

Further afield, Wikipedia describes the plant as “fairly widespread throughout the rest of Western and Central Europe, and it has also been recorded from Iran and North Africa’, although the same pressures will apply, as agriculture becomes more intensive and the world is “developed”.

In Norfolk in recent years the plant has had some help. Norfolk Wildlife Trust has worked with local councils, the Farming and Wildlife Advisory Group (FWAG) and private landowners to spread green hay from road verges where the plant has flowered and set seed, to introduce it (and other rare plants) to new sites, as described in the Diss Mercury from July 2008. Happily, the work has yielded results.

Sulphur Clover makes a well behaved and lovely garden plant too. The BBC Gardeners World website has information on growing it, ideally on chalky soil in dappled shade. It is hardy to below -20 Celsius. Normally you can buy the seed from Emorsgate Seeds, though I notice it is out of stock at the moment. Chiltern Seeds also sell it.

Sulphur Clover is attractive to insects and Garden Bumblebees (Bombus hortorum) were visiting the plant that I photographed.

Stopped in our tracks by Sulphur Clover

Stopped in our tracks on a bike ride, by Sulphur Clover.

Notes

Note 1 – The Online Atlas of the British and Irish Flora gives details of how the plant can suffer from tidying, excess competition or neglect – see the tab “Other Accounts”.

Green-winged Orchid, Anacamptis morio

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Green-winged Orchids, Anacamptis morio.

In mid May, Vanna and I cycled out to New Buckenham Common, a Norfolk Wildlife Trust reserve south-west of Norwich, to see Green-winged Orchids, Anacamptis morio.

It was a sunny day and we had a lovely bike ride, via back lanes from the outskirts of Norwich to New Buckehnam, bypassing the south of Wymondham and through Silfield, Wattlefield and Bunwell Bottom, avoiding the busier and hillier ‘B’ road used by most car drivers. I had been going on regular bike rides since the end of March, but it was Vanna’s first trip out since lockdown began in late March, and it was so good for us both to be out and about looking at plants and wildlife.

Although the main object of our visit was to see the Green-winged Orchids (Anacamptis morio) that grow on the Common, we also saw a nice selection of insects. These included numerous Craneflies, Small Yellow Underwing moths and our first Common Blue and Brown Argus butterflies of the year. The ground was much drier than usual after an exceptionally warm and sunny spring, and some of the orchids were already beginning to go to seed.

Green-winged Orchids flower from mid April to June, normally peaking in May, though the plants can flower as early as mid March. They are quite a small orchid (described by Simon Harrap as “dainty, usually petite”), usually 5 – 15cm (2 – 12 inches) tall, with unspotted leaves (note 1).

Green-winged Orchids are very variable in colour and range from a deep violet-purple through to rose-pink or whitish. The photograph above shows a fairly typical specimen. The Wild Flower Finder and Orchids of Britain and Europe websites show a good range of colour variations, and my photograph of a pink form on New Buckenham Common is below.

The orchid’s flower has three sepals and two petals and these form a hood, which is marked with the fine green or bronze veins that give the plant its English name (note 2).

Most Green-winged Orchids have no scent, but some plants with pink or white flowers smell strongly of vanilla, rather like a garden carnation.

Anacamptis morio

A pink form of Green-winged Orchid, Anacamptis morio.

Green-winged Orchids can be found in suitable places in much of England, Wales and Ireland and there are a few sites in south-west Scotland too. Unfortunately the species has declined as suitable sites have steadily been destroyed and old species-rich grasslands have been ploughed up or “improved” (note 3). “Improvement” is death to Anacamptis morio and many other wild flowers.

The orchids survive in the few remaining meadows and on commons and village greens, dunes, in churchyards, on the edges of golf courses, on neutral grassland on heaths, on roadsides, in lawns and in railway cuttings and gravel pits. The plant prefers damp pastures on clay soils but can grow on chalk, or on sands and gravels. It doesn’t like shade, so is seldom found in woodland.

The orchid can also be found elsewhere in Northern Europe. Further south, its relative Anacamptis picta, which is usually shorter and more spindly, seems to replace it, though telling the two species apart is not at all easy.

An older scientific name for Anacamptis morio is Orchis morio. The name change is a result of molecular data and the two genera can’t be distinguished morphologically (note 4).

The Plant Life website tells us more about the Green-winged Orchid’s names. Morio means “fool” and refers to the jester-like motley of the orchid’s green and purple flowers.  In Scotland, the plant’s names apparently include hen’s kames (combs), bull’s bags, dog’s dubbles, keet legs and deid man’s thoombs (dead men’s thumbs)! The generic name Anacamptis comes from the Greek word anakamptein, which means “to bend backwards”.

Many orchids can form hybrids and the Green-winged Orchid is no exception. In the British Isles, hybrids occasionally occur between Anacamptis morio and the Early-Purple Orchid, Orchis mascula. Historically, hybridisation has also occurred with the Loose-Flowered Orchid, Anacamptis laxiflora (in Shetland pre-1986) and with the Heath Spotted-Orchid, Dactylorhiza maculata (in Wiltshire, in 1994).

Green-winged Orchids are perennials and are thought to be long-lived. They are slow to colonise new sites but will spread by seed. Pollination is carried out by bees, especially bumblebees, but the plant doesn’t produce any nectar as a reward. Bees usually visit just a single flower on each of several plants, before moving on to other species with more rewarding flowers. In spite of this, most flowers are pollinated in the UK. Each seed capsule produces around 4,000 seeds. The seeds are very small and light and each needs a mycorrhizal fungus to develop further, but artificial fertilisers kill off many fungi, which is one reason why “improvement” of grassland is such a bad thing for the orchid.

It was good to see Green-winged Orchids again. We used to see them when we cycled in Suffolk, including large numbers at Chippenhall Green near Fressingfield. But New Buckenham Common was the spot where we first saw them, back in the early 1990s. We were given a lift out one evening by a friend  and had a good view of the orchids. But we ended up having to climb over an electric fence to escape some very frisky cattle grazing on the Common. By contrast, our more recent trip was without incident!

Notes

Note 1 – I recommend Simon Harrap’s book “A Pocket Guide to the Orchids of Britain and Ireland” (Bloomsbury, 2016) as a pocket-sized mine of information on British orchids, including lots of photos and information on their distribution and biology. I have taken a lot of my information from this lovely book.

Specimens of Green-winged Orchid can grow to 50cm (20 inches) tall on occasion.

Note 2 – The Early Purple Orchid, Orchis mascula, is superficially similar but its leaves are normally spotted and it is more likely to be found on a woodland ride or at the edge of a wood than the Green-winged Orchid, which grows in grassland such as commons. The flowers lack obvious dark veins on their sepals. Only the upper sepal and petals form the hood of the flower; the two lateral sepals are held upright to form “wings”.

Note 3 – I hate the term “improved” when applied to grassland. It is the verbal equivalent of the ministries in George Orwell’s “1984”, meaning the exact opposite for those of us who love the natural world. The natural diversity of grassland is deliberately reduced to provide lusher grassland for livestock, by applying artificial fertilisers or even ploughing and re-seeding. The result is a bright green sward dominated by Perennial Rye Grass (Lolium perenne) and with a very limited number and range of flowers.

See “B4 – Improved Grassland” on Norfolk Wildlife Trust’s Habitat Definitions and Coding handout for more information on how to recognise this damaged grassland.

“Don’t it always seem to go
That you don’t know what you’ve got til its gone
They paved paradise
And put up a parking lot.”

Joni Mitchell, “Big Yellow Taxi“.

Note 4 – Clive Stace, “New Flora of the British Isles“. Fourth Edition, 2019.

Crosswort, Cruciata laevipes

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Crosswort, Cruciata laevipes

Crosswort, Cruciata laevipes, growing in the mini-meadow in our back garden.

Crosswort, Cruciata laevipes, is in full flower at the moment. The plant is like a fuzzy, soft focus version of Lady’s Bedstraw, Galium verum, which I wrote about last July.

Both plants are perennial members of the Bedstraw family, the Rubiaceae. Both have whorls of leaves and flowers but Crosswort has softer, wider, paler green leaves in whorls of four rather than the six to eight thinner, darker green leaves of Lady’s Bedstraw. Crosswort is altogether a softer, floppier plant than Lady’s Bedstraw.  Lady’s Bedstraw has bright yellow flowers, while Crosswort’s flowers are a paler yellow. Lady’s Bedstraw smells of new-mown hay when in flower; Crosswort’s flowers have the delicious scent of honey.

Crosswort is a British native wild flower of well-drained neutral or calcareous soils. It can be found growing on road verges and in hedge banks, in ungrazed grassland, in open scrub and on woodland rides and edges. It becomes scarce from central Scotland northwards and is rare in Ireland, where it is considered to be an introduction. The plant occurs throughout much of Europe as well as in northern Turkey, Iran, the Caucasus, and the western Himalayas. It has also been introduced to parts of New York state (Ontario county) in the United States.

Considering that the Online Atlas of the British and Irish Flora shows records for Crosswort across much of England and Wales, it is a plant I rarely see growing wild here in Norfolk, perhaps because it prefers calcareous soils.

My first encounter with Crosswort was on a road verge just outside Edinburgh in 1983, where I knew it by its old name, Cruciata ciliata. (Another former name is Galium cruciata.) In Norfolk I have seen it growing on a couple of road verges, near Metton in North Norfolk and recently just north of New Buckenham (note 1).

I have several patches of Crosswort in the garden, all of which came from a single pot-grown plant bought from Natural Surroundings in North Norfolk in 2013. Planted in fertile sandy loam in a border, my Crosswort grew and grew, spreading through the border. I removed most of it but the smallest pieces grew back. Something similar has happened in the border at the far end of the garden. Crosswort is a tough, hardy plant and definitely likes its growing conditions here, happily tolerating the winter shade in our north-facing back garden and regular droughts. I am happy for it to spread, up to a point, not only for its glorious flowers but because its dense ground-hugging habit provides lots of cover for spiders and insects. But after flowering I pull out excess handfuls of it.

The Scottish Wildflowers website says that Crosswort’s flowers “are followed by black berries, about as large as currants, which remain attached to the plant till late in winter”. This is true for Crosswort’s relative Wild Madder, Rubia peregrina, but not for Crosswort, which has one or two inconspicuous nutlets.

Crosswort is also known as Smooth Bedstraw, Maywort and Maiden’s Hair. Its Scots Gaelic name is Luc Na Croise. Cruciata means crucified and laevipes refers to Crosswort’s smooth stalks.

Crosswort has been used medicinally and the Plants For A Future website lists several past uses. These include the treatment of wounds and obstructions of the stomach and bowels. The plant was also used to stimulate the appetite and to treat rheumatism, rupture and dropsy. The leaves are edible raw or cooked, though I haven’t tried them.

As ever, the Wildflower Finder website has a series of excellent photographs of the plant, which I recommend.

Notes

Note 1 – Thanks to Mike Ball for telling me of two more Norfolk sites for Crosswort: on the road leading out of Hanworth towards Sustead and on Emery’s Lane at Hanworth.