Triadenum fraseri (Spach) Gleason
Family: Hypericaceae
Triadenum fraseri image
Paul Rothrock  
Perennial herb 30 cm - 0.6 m tall Leaves: opposite, stalkless, 3 - 6 cm long, 1 - 3 cm wide, oblong to egg-shaped or elliptic with a more or less heart-shaped base and a rounded to notched tip, non-toothed, covered with translucent glands and dark dots beneath. Flowers: borne in axillary or terminal clusters, with 3 - 5 mm long sepals that are elliptic to oblong with a rounded to blunt tip, five pinkish petals 5 - 8 mm long, 0.5 - 1.5 mm long styles, and nine stamens forming three groups of three that alternate with three glands. The flowers usually remain closed, especially in sunlight. Fruit: a three-chambered capsule, purplish, 7 - 12 mm long, egg-shaped to cylindrical, narrowing abruptly at the tip, vertically ribbed, many-seeded. Stems: erect, branching near the top or remaining unbranched.

Similar species: Triadenum virginicum has 5 - 8 mm long sepals at maturity, pointed sepal tips, and styles 2 - 3 mm long.

Flowering: mid July to early September

Habitat and ecology: Locally common in moist areas such as bogs, marshes, moist calcareous sand, and very limy (marly) fens.

Occurence in the Chicago region: native

Etymology: Fraseri was named after Scottish plant collector John Fraser (1750 - 1811).

Author: The Morton Arboretum

From Flora of Indiana (1940) by Charles C. Deam
The variety has the habitat of the species and almost the same range in Indiana.


Indiana Coefficient of Conservatism: C = 8

Wetland Indicator Status: N/A

Much like no. 1 [Triadenum virginicum (L.) Raf.]; sep elliptic or oblong, obtuse or rounded, 3-5 mm; pet 5-8 mm; fr ovoid or cylindric, 7-12 mm, rather abruptly narrowed to the 0.5-1.5 mm styles. Bogs, marshes, and wet shores; Nf. and Que. to Minn., s. to Conn., N.Y., O., n. Ind., and Neb., and in the mts. to W.Va. July, Aug. (Hypericum f.)

Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.

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