Babington's Leek (Allium ampeloprasum) is the ancestor of the cultivated vegetable. In the UK it grows on sandy and stony soil near the coast though it seems to be doing well here on the allotment.
 The leeks we eat today are a biennial grown from seed. We generally eat them in the first year of growth rather than letting them flower in the second, unless we want to collect the seed. Babington's Leek is a perennial that grows from a cloved bulb. It throws up a a slender stalk whereupon a head of flowers and tiny bulbils bursts out of the spathe.

 At ground level A. ampeloprasum looks similar to conventional leeks.

 The stalks have a tendency to lean which is a mechanism to deposit the bulbils away from the parent plant thus increasing the spread. I believe Egyptian Walking Onions do the same thing. Walk like an Egyptian?!

 This stalk seems to be gearing up to shed bulbils round corners!