Common Name: cup plant, cupleaf rosinweed, squarestem rosinweed, cup rosinweedScientific Name: Silphium perfoliatum L.Family Name: Asteraceae (Compositae) - Aster or Sunflower FamilyIdentification NotesLife Cycleintroduced perennial, reproducing by seed and creeping rootstocks Stemsupright, tall, stout, square, mostly smooth, green but sometimes reddish, unbranched below with some branching above Leavesopposite, broadly lanceolate to oval, white veins, rough, margins strongly toothed, connate-perfoliated with leaf bases joining around stem to form a “cup” Flowersheads of bright yellow rays (ligulate) florets around center of yellow or pale yellow disk (tubulate) florets; clusters terminal and axillary above, open, long stalked