No, not the dreaded Rattus rattus or any of its vile kin, but the wonderful Rat’s Tail Radish, or Raphanus caudatus:

I have fed the seed pods of this plant, which looks like a cross between a green bean and a snap pea, to various visitors to BRTG.  For a few seconds, most are unimpressed, thinking it to be a rather pedestrian pod of no particular pedigree.  But soon, the sharp after-bite kicks in, and the typical taster asks, “Is this some kind of pepper?”  Only a professional chef of considerable renown immediately identified the flavor as radish, showing that most of us taste with our eyes and not the tongue. 

This heirloom plant is easy to grow, tolerating New York’s summer heat, and is long bearing, with attractive and edible flowers. 

It was introduced to England from Java in 1815, and gained significant social standing when introduced to the Prince of Wales’ garden at Sandringham.  It received a favorable mention from Andrew Jackson Downing in 1860.  A now, a perfect, easy growing, tasty and versatile addition to urban green roofs.