Flower:

A single spike at the top of the stem, lance-elliptic in outline, 3 to 7 mm (to ~¼ inch) long, with 3 to 9 florets spirally arranged, each floret subtended by a single scale. Scales are 3 to 4 mm long, the midrib slightly extended at the tip, reddish to brown. Florets have 3 stamens and a 3-parted style. At the base of the spike is a single, erect bract about as long as the spike, scale-like with a green midrib that extends to a very short awn.

Leaves and stems:

Leaves are mostly basal. A single stem leaf less than ½ inch long is near the base. Sheaths are concave at the tip. Stems are slender, grooved (or ridged), round in cross-section, smooth, and only a few inches tall at flowering time but extend up to 16 inches at maturity.

Plants form dense clumps, the old dead stems and sheaths persisting and building up around the clump of new growth.

Fruit:

Each flower produces a single achene (seed), that drops off independently of the scale, the scales usually dropping first. Achenes are 1.4 to 1.7 mm long, dark brown to blackish, smooth and somewhat shiny on the surface, compressed 3-sided in cross-section, urn-shaped in outline, rounded at the tip end and tapering at the base. Surrounding the achene are 6 brown bristles that are as long as or slightly longer than the achene.

Notes:

Tufted Bulrush, sometimes misspelled T. caespitosum, is a circumboreal species of wet, marly or rocky habitats, including bogs, fens and is a common sight on the rocky north shore of Lake Superior. It is native to parts of Europe and Asia as well as the northern latitudes and higher altitudes of North America. Trichophorum Bulrushes, with their short stature and single terminal spike, look less like other Bulrushes and more like Spikerushes (Eloecharis species). Spikerushes have smooth, round or compressed stems that are not grooved, 2 leaves per stem that are reduced to bladeless sheaths, the bract at the base of the spike is not much different from the floral scales and lacks a green midrib, and achenes usually have a cap-like appendage (tubercle) at the tip.

Tufted Bulrush is distinguished by its single spike, grooved/ridged stems that are smooth, nearly leafless, and round in cross-section, and dense tuft of old, persistent stems and sheaths. It is most similar to Clinton's Bulrush (T. clintonii), which has 3-sided stems and more conspicuous stem leaves that (at flowering time) may be as long as the stem.