About Triosteum perfoliatum L.
Triosteum perfoliatum L. produces an unbranched, light green, hairy stem that reaches heights of 61–107 cm (24–42 in). Opposite leaves grow in pairs joined around the stem, with each pair oriented at a 90-degree angle from the previous pair along the stem. Individual leaves can grow up to 20 cm (8 in) long and 10 cm (4 in) wide, and have smooth margins. Reddish-brown flowers form clusters on very short stems in leaf axils; they are tubular with five small lobes. The fruit looks like small oranges and stays attached to stalks through autumn. Each drupe holds three black nutlets. Triosteum perfoliatum is native to the United States, ranging east to Massachusetts, west to Nebraska, south to Louisiana, and north to the Canadian border. It is native to Ontario, Canada, where it is classified as an endangered species. It is possibly extirpated in Louisiana, extremely rare and endangered in Massachusetts, and extremely rare and listed as a species of concern in Rhode Island. This plant grows in dry open woods, on hillsides and in valleys. Triosteum perfoliatum flowers bloom from May to July. The blooms attract a variety of bees, most notably bumblebees (Bombus spp.) and anthophorid bees (Anthophora spp.). It also acts as a larval host plant for Hemaris diffinis, the snowberry clearwing moth.
