Montana Field Guide

Caespitose. Stems erect, 5–50 cm. Leaves basal and cauline; blades 1–3 mm wide. Inflorescence of 4 to 12 sessile spikes in a dense head; lower bracts erect, much longer than the inflorescence. Spikes 4–8 mm long, all similar; female flowers above few male. Perigynia erect, linear-lanceolate, green to tan, wing- and serrulate-margined, 3–6.5 × 0.8–1 mm, tapered to the serrulate beak, 3–5 mm long; stigmas 2. Female scales lanceolate, acuminate, tan-hyaline with a green midvein, shorter or longer than the perigynia. Achene 2-sided, smaller than the perigynium (Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).

Fruit mature in July-August.

The combination of long, leaf-like lower bracts, and long, narrow perigynia is distinctive.

Moist soil of meadows along streams and ponds in the valleys and on the plains.

STATE THREAT SCORE REASON
Reported threats to Montana's populations of Many-headed Sedge concern factors presumably responsible for extinction of two populations. One population was destroyed where a dock was constructed. Another population was lost where a wetland was drained to expand agricultural use. Hydrological alteration actions that dewater or inundate Many-headed Sedge habitat pose a threat to several populations located where it is employed for agricultural benefit. Remaining populations occur in places where it may be desirable for development or agricultural expansion which would displace plants and/or fragment populations and further habitat degradation (MTNHP Threat Assessment 2021).