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]

References

  1. ^ "Lady Bird Johnson Wildflower Center - the University of Texas at Austin". wildflower.org. Retrieved 2023-12-29.
  2. ^ "BONAP's Map".
  3. ^ Thoday, D. (1931). "The Significance of Reduction in the Size of Leaves". Journal of Ecology. 19 (2): 297–303. doi:10.2307/2255823. JSTOR 2255823.
  4. ^ "US Wildflower - Pineweed, Orangegrass - Hypericum gentianoides". USWildflowers.com. Retrieved November 21, 2022.
  5. ^ a b "Hypericum gentianoides (L.) B.S.P." (PDF). Michigan Natural Features Inventory. Retrieved November 21, 2022.
  6. ^ "Hypericum gentianoides (Orange-grass St. John's-wort): Go Botany".
  7. ^ "DSpace Angular Universal".