06-July London’s Peas & Thistles

Summary

July’s meadows and wastelands erupt in a riot of pea flowers—crimson, cream, and violet—while thistles stand guard with silvered leaves and golden blooms. Discover why railway banks blaze with everlasting peas, which vetch once flavoured Christ’s hay, and how the musk thistle became nature’s lightning rod. But beware: some beauties bite back with spines sharp enough to draw Tudor blood.

Return on 06 July to explore London’s most defiant—and delicate—summer blooms!

Article

Peas and vetches

A whole host of new plants with pea-like flowers are now starting to appear. They include an impressive range of bright, clear colours with many possessing some delicate pencilling on the petals. There is a confusing group of true peas, vetches, vetchlings, clovers, trefoils, tares, melilots and greenweeds, some of which can be quite difficult to identify in the field with any great certainty. The typical pea flower has two distinct wings on its sides, an erect standard in the middle and a keel below made up of two petals joined together. Within the keel the styles and stamens can be found. The petals themselves can be a great range of colours and in some species even change colour.

06-July London’s Peas & Thistles Section Image

06-July London’s Peas & Thistles Section Image

Three of the most commonly encountered are tufted vetch Vicia cracca, bush vetch V. sepium and common vetch V. sativa. The first has a very one-sided flowerhead made up of many bluish-violet flowers almost crushed together.

06-July London’s Peas & Thistles Section Image

06-July London’s Peas & Thistles Section Image

Bush vetch has a smaller number of flowers which are reddish-purple with distinctly darker wings. Common vetch has even less flowers, often just groups of two along the stem, which are usually purple but can be pink.

06-July London’s Peas & Thistles Section Image

06-July London’s Peas & Thistles Section Image

Another quite commonly encountered attractive yellow pea in London is the meadow vetchling Lathyrus pratensis which is also found in gardens. A similar but paler yellow pea could be the very much rarer yellow vetch Vicia lutea.

06-July London’s Peas & Thistles Section Image

06-July London’s Peas & Thistles Section Image

There are also other, usually short-lived, colonies of peas that turn up from time to time e.g. the bright crimson tuberous pea Lathyrus tuberosus and the Tangier pea L. tingitanus which may owe its appearance to discarded bird seed. The hairy vetchling L. hirsutus with its red and blue flowers and Dragon’s teeth Tetragonolobus maritimus which has bright yellow flowers on long stalks, are two more.

A much larger, brighter pink pea familiar to railway commuters is the broad-leaved everlasting pea Lathyrus latifolium which is common on railway embankments. Its flowers can vary from pink to purple and even magenta.

06-July London’s Peas & Thistles Section Image

06-July London’s Peas & Thistles Section Image

It has a rarer close relation, the narrow-leaved everlasting pea L. sylvestris which unsurprisingly can be separated by its leaf width. Other striking large pea flowers include sainfoin, lucerne and wild liquorice. Sainfoin Onobrychis viciifolia is a dramatic pink with purple veins and is beautiful enough to be included in the list of plants that made up the hay in Christ’s crib. Wild liquorice Astragalus glycyphyllos has unusual pale cream flowers, which are slightly greenish.

06-July London’s Peas & Thistles Section Image

06-July London’s Peas & Thistles Section Image

This is not the liquorice we eat which is another species. This has a sweet taste which eventually turns to an unpleasant bitter one. Lucerne, or alfalfa Medicago sativa has been grown as a crop since the seventeenth century. It was believed to increase milk yield and fatten horses. More recently it has been grown for silage. Whenever it was seen, alien plants would appear nearby, especially starthistles. These have very fierce spines which Gerard points out “were not to be touched without hurt”. Both lucerne and wild liquorice can still be found on Headley heath.

Then there are the peas found in the wild that originated from our gardens e.g. the broad bean Vicia falsa, spring vetchling L. vernus, the true everlasting pea L. grandiflora and the most celebrated of all, the sweet pea L. odoratus.

06-July London’s Peas & Thistles Section Image

06-July London’s Peas & Thistles Section Image

Two much smaller, almost tiny scrabbling species are the smooth (V. tetrasperma) and hairy tare V. hirsuta. These are the tares mentioned in the bible as wild plants that spoilt crops. Their seeds were not easily separated from grain resulting in an unpleasant taste in the flour. Hairy tare has slightly paler purple flowers than smooth tare and its calyx is much hairier.

06-July London’s Peas & Thistles Section Image

06-July London’s Peas & Thistles Section Image

Among this wonderfully diverse group of July flowers one of the rarest and possibly the most beautiful is the wood vetch V. sylvatica. Its flowers have creamy white wings and keel but a pale lilac standard covered in fine purple veins. This is now gone from London but for any budding enthusiast it can still be found in the Chilterns. The rest of London’s peas are well distributed, especially in hedges, grassy areas, railway embankments and heath. Horsenden hill is a good place to find a variety of these plants.

Thistles

Most thistles flower in July. Even early species which are running to seed will still sport a flower or two. As most of them are now tall we tend to notice them more. The least attractive is unfortunately the most common. This is the creeping thistle Cirsium arvense which forms large dull patches due to its creeping habit. The next most likely to be encountered is the spear thistle C. vulgare which seems to be in every corner of London with its long ferocious spines, both on its leaves and especially on its stems.

06-July London’s Peas & Thistles Section Image

06-July London’s Peas & Thistles Section Image

The welted thistle Carduus acanthoides is another common species which is more often seen on roadsides. Its stems are distinctly winged or welted along their sides and its leaves are very spiny and slightly waved.

06-July London’s Peas & Thistles Section Image

06-July London’s Peas & Thistles Section Image

The marsh thistle Cirsium palustre is similar to the welted but found in damper areas. It has lines on its stem which the welted has not. It also has a winged stem but in this case the spines are purple. This thistle can be the most elegant of all when seen in abundance, especially in one of its preferred habitats, the wet sides of paths in damp woods. Then it can reach two metres in height with long, imposing, upward pointing branches carrying either white or purple flowers.

Other thistles seen this month are less easily confused. The woolly thistle C. eriophorus is huge with a very woolly flowerhead which later develops red-tipped spines. The milk thistle Silybum marianum like the woolly thistle is rarely seen in the wild but is often planted in gardens due to the attractive milky-white markings on its leaves.

06-July London’s Peas & Thistles Section Image

06-July London’s Peas & Thistles Section Image

The giant downy white thistle also noticed in gardens is the scotch or cotton thistle Onopordon acanthium. Being so impressive it is often said to be the thistle emblem of the Stuarts in Scotland although the humble spear thistle is a much more likely candidate.

On downland two other much smaller thistles get noticed especially by picnickers when they sit on them. One looks golden yellow and opens and closes its flowers depending on how wet it is. This is the carline thistle Carlina vulgaris. The other is the stemless thistle Cirsium acaule which is purple rather than golden and not surprisingly stemless. Another less often seen but attractive thistle is the slender thistle Carduus tenuiflorus. This is best looked for along the tidal Thames. It is similar to the welted thistle but more slender and with much paler flowers.

06-July London’s Peas & Thistles Section Image

06-July London’s Peas & Thistles Section Image

A very rare casual thistle is the yellow-flowered star thistle Centaurea solstitialis which is more at home around the Mediterranean. Arguably the most beautiful of all the group is the musk thistle Carduus nutans. It has large drooping or nodding flowers with no spines on its flower stalks. It also has a musky scent that even extends to its leaves. It can still be found in heavily grazed areas along the Colne Valley. In such places it often stands quite alone. If near a house its presence was always a good omen, indicating the building would never be hit by lightning.

06-July London’s Peas & Thistles Section Image

06-July London’s Peas & Thistles Section Image