Pretty, dainty Tufted Vetch started flowering a couple of weeks ago in Surrey. This is the only vetch I can positively identify because its flowers form long purple rows on one side of the stem, almost like over-populated miniature bluebells.
Tufted Vetch is of the pea family so when these flowers become seeds they will be held inside green, then black (when they’re ripe), seed pods. Irving describes Common Vetch but notes that the peas of other vetches are small but good to eat too. The ‘Plants for a Future’ database lists the tiny seeds as edible after boiling or roasting and also states that the leaves are a tea substitute.
My usual confusion about vetches comes from the leaves, which look the same for many of the other species – having opposing leaflets like a ladder along the stem.
Several species, including this one, are too weak to stand tall under their own strength and so use branched tendrils at the end of their leaves to twist and grip onto other plants and drag themselves into the sunlight – sometimes up to 2 metres in height. This one is growing amongst the Ox-eye Daisies I wrote about some time ago (which are now looking a little worse for wear).
It’s not a lazy plant though, not by a long shot. Plants of the pea family are leguminous, that is they grow nodules on their roots which house symbiotic bacteria which can fix nitrogen from the air into the soil. They thus provide the nitrate ‘fertilizer’ that other plants need to grow… …so they can be forgiven for using them for a little support here and there. We humans can fix nitrogen too, industrially using the Haber Process. It takes about 500 °C and 200 atmospheres of pressure to make ammonia from hydrogen and air which can then be oxidized to nitrates for artificial fertilizer. I bet those Tufted Vetch root nodules aren’t at 500 °C.