Hogfennel

Peucedanum palustre (marsh hog's-fennel, milk parsley) is an almost glabrous biennial or short-lived perennial of the carrot family (Apiaceae), growing 60–150 cm tall from a stout taproot. The hollow, ridged, often purplish stems exude a thin foetid milky latex when broken in young growth. Leaves are large and two- to four-times pinnate, with finely dissected, narrowly lance-shaped ultimate segments giving an overall feathery appearance. Small white flowers are borne in compound umbels 4–8 cm across, with each umbel composed of many rays and subtended by narrow bracts, flowering from July to September. The fruit is a flattened, broadly elliptical schizocarp 4–5 mm long with three thin dorsal ridges that are not winged and broader lateral wings, distinguishing it from related species. Native to most of Europe and extending eastward into central Asia, milk parsley inhabits fens, wet meadows, marshes, riverbanks, ditches, and shallow water at estuary margins, and is the principal larval food plant of the British race of the swallowtail butterfly.