Hypericum Species, Roundseed St. Johnswort, Round-fruited, Round-podded St. John's Wort

Bumblebees and other long-tongued bees are probably the most important pollinators of the flowers. Other visitors include Halictine bees,...Read More beetles, and Syrphid flies, but they are less effective at pollination. All of these insects collect or feed on the abundant pollen, because the flowers offer no nectar. The caterpillars of the butterfly Strymon melinus (Gray Hairstreak) reportedly eat the seed capsules, although it is not a preferred host plant. The caterpillars of the moth Nedra ramosula (Gray Half-Spot) feed on the foliage. Like other St. John's Worts, the foliage of this species contains a toxic chemical that causes photosensitive skin reactions, particularly in light-skinned animals, and can irritate the gastrointestinal tract. Therefore, mammalian herbivores usually leave this plant alone if other food sources are available.