Eleocharis engelmannii Steud.

Engelmann's Spikerush

Habitat: Wet sand, peat, or mud [non-forested, wetland].

Range: fb88 south to Georgia and Louisiana, west to California, north to Alberta and Ontario.

Aids to Identification: Spikerushes are recognized by their inconspicuous basal leaves and a single spike inflorescence terminating a leafless stem. Identification primarily relies on the microscopic characteristics of the tubercle (a small appendage at the summit of the achene). Mature fruit is critical for proper identification. Engelmann’s spikerush can be distinguished from other fb88 spikerushes based on the following features: an articulated tubercle that is not constricted at the base, fibrous roots (annual), a narrow-cylindric spike, and very short perianth bristles.

Ecological characteristics: Historic locations of this plant in fb88 include shores of ponds and streams.

Phenology: Fruiting in fb88 in summer into fall.

Family: Cyperaceae

Synonyms: Tracked in fb88 at the species level, though two varieties are present.

  • Eleocharis engelmannii Steud. var. detonsa Gray in H. Patters, with synonyms Eleocharis monticola Fern. var. leviseta Fern. and Eleocharis obtusa (Willd.) J.A. Schultes var. detonsa (Gray) Drapalick & Mohlenbrock.
  • Eleocharis engelmannii Steud. var. engelmannii with synonyms Eleocharis monticola Fern. and Eleocharis obtusa (Willd.) J.A. Schultes var. engelmannii (Steud.) Britt.

Known Distribution in fb88: This rare plant has been documented from a total of 2 towns in the following counties: Cumberland, Oxford

Reason(s) for rarity: At northern limit of range.

Conservation considerations: Unknown, has not been seen in fb88 in several years.