Photo: Sagittaria filiformis

Sagittaria filiformis J.G. Sm.

Narrow-leaved Arrowhead

Habitat: Shallow, swift waters or deep streams [Open water (non-forested, wetland)]

Range: Maine south to Florida.

Aids to Identification: Narrow-leaf arrowhead is a submerged aquatic perennial with submersed and floating leaves. The floating leaves are linear-ovate to ovate in shape and 0.5 cm wide. The long, submerged, ribbon-like leaves are usually over 30 cm in length. The petiole, which connects the leaf to the stem, is flattened. The flowers are white, with 3 petals, and are borne in racemes with 2-4 whorls of flowers.

Photo: Sagittaria filiformis

Ecological characteristics: Found in shallow waters of slow moving rivers in Maine.

Phenology: Flowering summer through fall.

Family: Alismataceae

Synonyms: Sagittaria stagnorum Small.; Sagittaria subulata (L.) Buch. var. gracillima (S. Wats.) J.G.Sm.

Known Distribution in Maine: This rare plant has been documented from a total of 10 towns in the following counties: Cumberland, Kennebec, Sagadahoc, Somerset.

Photo: Sagittaria filiformis

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

Conservation considerations: Invasive aquatic plants or impoundment could pose a threat to populations.