It's quite likely (unless, like me, you spend your weekends crawling through meadows on green knees) that you have never heard of sulphur clover. I wouldn't hold it against you if you hadn't. Sulphur clover is an all-too-scarce representative of a meadow flora (on boulder clay in southern East Anglia) which has largely been eradicated from the landscape.
Sulphur clover had nearly gone from Norfolk until Helen Baczkowska of Norfolk Wildlife Trust - and subsequently several of her colleagues - made it their mission to save it. Working with landowners, communities and authorities, they have helped restore and recreate biodiverse meadows across South Norfolk, importing the seeds of native flowers in hay meticulously harvested from nearby remnants of a habitat all but lost. Spiny restharrow, zigzag clover, dyer's greenweed, fragrant agrimony, sulphur clover, and other declining plants of clay-rich ancient meadows, have all been helped to recolonise south Norfolk in this way.
These plants have reclaimed small parts of a landscape where they thrived for centuries. And, just as importantly, they have been reclaimed as local heritage by people who – with Helen's guidance – have become champions for these and other declining species.