P. officinale: stem terete, striated, 2-3 feet high; leaves five times tripartite, the leaflets linear-acute, flaccid, very long, narrow; flowers yellow, in large umbels of twenty or more rays; general involucre three-leaved, deciduous; pedicels much longer than the fruit. - Hog's Fennel or Sulphur-weed. - Salt marshes, rare. Fl. July to September.