Triosteum perfoliatum is a perennial herb, to 1.3 m, stems hairy, rather coarse.
Leaves opposite, stalkless (sessile), widest above middle, to 30 x 15 cm, narrowed below middle, hairy above, densely hairy below, base joined across stem, fused (perfoliate) base to 9 cm wide.
Flowers dark red to greenish-yellow, tubular, to 1.7 cm long, densely glandular-hairy, base swollen on one side, petal-lobes 5, unequal, spreading, calyx lobes to 1.8 long, 0.1 cm wide, hairy, linear, in small axillary clusters of 3-4; blooms May-July.
Fruit fleshy, orange, rounded, Aug.-Oct.
Wetland status: UPL.
Frequency in NYC: Very infrequent.
Origin: Native.
Habitat: Open woods, edges. . Accessed 5/2014).