Hypericum gentianoides is a species of flowering plant in the St. John's wort family Hypericaceae. Its common names include orangegrass and pineweed.
Native to eastern North America, it ranges from Ontario; Nova Scotia and Maine south to Florida, west to Texas, and north to Missouri and Minnesota.[1] [2]
It is an annual herb typically growing 10–40 cm tall. The leaves are repressed against the stem, 1-3mm long, and scale-like; an adaptation to reduce transpiration in exposed environments.[3] The flowers are no more than 3mm across, with five to ten stamens, and three styles.[4] [5] It commonly grows in nutrient poor soil, sand, and on exposed sites, but is also known to occur in wetter areas such as coastal plain marshes.[5] The name orangegrass refers to the citrus smell that is released when it is crushed.[6] Chemical extracts of H. gentianoides have been found to inhibit the contraction of HIV.[7]