Fraser's Marsh St. Johnswort (Triadenum fraseri)

Fraser's Marsh St. Johnswort (Triadenum fraseri)

Fujifilm Finepix XP55 photograph

Fraser's Marsh St. Johnswort (Triadenum fraseri), also known as Marsh St. Johnswort and Bog St. Johnswort, is an emergent plant found in wetlands, marshes and on the shores of ponds and lakes. It is a perennial forb that can grow to about two feet (61 centimeters) in length.. The genus name is Greek for "three glands."  The species name is in honor of John Fraser, Jr. (1789 - 1861), a Scottish student of North American plants. It is a member of the Mangosteen Family (Clusiaceae). The order is Theales. Some authorities have renamed this order, Ericales.

The flower is pink to red, five-parted and up to ¾ inch (19 millimeters) wide. The sepals are elliptical. The flowers are in clusters at the tip of a stem and in the axis of leaves. The Fraser's Marsh St. Johnswort blooms from July to early September.

The leaves of the Fraser's Marsh St. Johnswort are stalkless, about one inch (25 millimeters) long, sometimes twice as long, elliptical, opposite in pairs, about twice as long as wide and rounded at the tip. They are dull green with lighter margins and light, prominent veins. The margins are entire.

The stems and veins are green to reddish.

Fraser's Marsh St. Johnswort Size

The fruit is an orange, tappered capsule with three lobes or cells. These capsules drop into the water and float away to establish a new plant.

Fraser's Marsh St. Johnswort (Triadenum fraseri)

Fujifilm Finepix XP55 photograph

Like other emergent plants, Fraser's Marsh St. Johnswort helps filter runoff water before it enters the pond.

 

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