Aquatic and Wetland Vascular Plants of the Northern Great Plains
17. Clusiaceae, the Mangosteen Family
2. Triadenum Raf. -- Marsh St. John's-wort1. Triadenum fraseri (Spach) Gl.
Erect perennial from creeping rhizomes, 3-6 dm tall, the stem simple or branched above. Leaves elliptic-ovate to oblong, 3-6 cm long, 1-3 cm wide, pinnately veined, glaucous and brown or black dotted beneath, rounded or emarginate at the tip, broadly rounded to cordate-clasping at the base. Flowers in terminal and axillary clusters of usually few to several, short-pedicelled. Sepals oblong-ovate, 2.5-5 mm long, obtuse or rounded; petals pink to greenish or purplish, 5-10 mm long; stamens 9(12), united below into 3 fascicles, the fascicles alternating with orange glands; styles 0.5-1.5(2) mm long, ovary 3-celled. Capsule purplish, ovoid to oblong, 7-12 mm long, blunt-tipped; seeds brown, oblong-ellipsoid, ca. 1 mm long. Jul--Aug. Marshes and shores; uncommon in NE Sand Hills; (Que. and Newf. to w MN, s to WV, IN and NE). Hypericum virginicum L. var. fraseri (Spach) Fern.
Previous Species -- Hypericum majus (A. Gray) Britt. -- Greater St. John's-wort
Return to Family -- Clusiaceae - The Mangosteen Family
