17-Mar Shamrocks & Speedwells

In similar areas of short grass and at the edge of paths daisies, dandelions and speedwells are all now getting more common. Mediaeval pilgrims picked speedwell flowers and wore them in their lapels believing it would hasten their journey to Canterbury. At this time of year it is still one of the brightest flowers you are likely to notice walking along sections of the Pilgrims Way on the North Downs. The first to be noticed is usually the Persian speedwell Veronica persica with its red stems and sky-blue flowers and with just a single milky-white petal. The other large and brightly-flowered speedwell now is Germander speedwell V. chamaedrys. It also has red stems but with two distinct rows of hairs running down their length. There are several other speedwells that can be seen in March but they all tend to have smaller flowers and leaves.

Like all the speedwells they tend to prefer the edges of paths, lawns and fields although it is also worth looking for them on walls and in churchyards. You can often make an educated guess by just looking at the flowers and leaves and their English names can often give a clue to their identity e.g. deep blue flowers and grey green leaves (Grey field speedwell V. polita), pale lilac flowers with dark veins and more ivy-shaped leaves (Ivy-leaved speedwell V. hederifolia),

blue flowers with long stalks and round or kidney-shaped leaves (Creeping speedwell V. filiformis), bright blue flowers clustered at the end of stems and toothed, hairy leaves (Wall speedwell V. arvensis), pale flowers with distinct blue lines and leaves with virtually no lobes Thyme-leaved speedwell V. serpyllifolia), pale blue flowers with a white lower lip and pale green leaves (Green field speedwell V. agrestis). However, sometimes their colours are variable and there are also some white forms so you may have to resort to sepals or fruits to confirm any identification.

Another plant seen more now at the edge of roads rather than paths is early scurvy grass Cochlearia danica. This newcomer was unknown in London forty years ago when the plant was normally found on shingle banks beside the sea. Sea salt on roads has been responsible for its recent invasion inland. It is currently marching along roads at ten to fifteen miles a year. Subject to dwarf forms, all that motorists notice is an elongated thin white carpet of tiny white flowers bordering the edges of main roads.

A quite different flower this month and one that is easily ignored is the first of our woodrushes Luzula spp. They are relatively easy to get to know as there are only ten in Britain. They essentially look like hybrids between a grass, sedge and rush. Their leaves are broad and flat like a grass, their stems strong and upright like a rush and their flowers small, dark and petalless like a sedge. The stiff stems and dark, compact flowers led to them being called ‘chimney sweeps’. The field woodrush L. campestris is a typical early species. About seven to ten centimetres high with a tight cluster of small dark brown flowers it was called Sweep’s brush. In woods a different species may be found, the hairy woodrush L. pilosa. This is twice the size and with hanging clusters of more purple-brown flowers that hang even more when they have been fertilized.

One of the forgotten rare flowers of March is the yellow star-of-Bethlehem Gagea lutea. The last one in London is said to have been inadvertently picked by a schoolgirl in Broxbourne Woods in 1954. Even when present it was always difficult to find, being shy to flower and easily lost in among similar-looking celandines. Though it is now very rare in Britain it does occur in the rest of Europe and all across Russia as far as the Kamchatka peninsula.

There are, however, two garden star-of-Bethlehems, Ornithogalum umbellatum and O. nutans that can sometimes be found flowering precociously early in Nonsuch Park. Across the rest of London various aliens may turn up here and there e.g. hoary mustard, yellow fumitory, narrow-leaves ragwort, hairy garlic, the three-cornered leek and the Adria bellflower from the Balkans. March is a good time to look for London’s other aliens especially ruderal species which like to grow beside or near the river Thames.