Lvs with an elongate, slender petiole 1.5-10+ cm and a lanceolate to elliptic blade 1-3 cm נ2.5-12 mm; cor 2.5-3.5 mm; otherwise much like no. 2 [Limosella subulata Ives]; 2n=40. Muddy shores; interruptedly circumboreal, reaching our range in w. Minn. June-Sept.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
General: Perennial, small, tufted, often forming mats; scapose, often submerged with floating leaves; herbage glabrous; roots fibrous. Leaves: Basal, narrowly spatulate or broadly oblong-elliptic, 1-3 cm long, 3-12 mm wide, mostly 3-veined, glabrous, margins entire; petioles long, some as long as the water is deep, the base broadly expanded into membranous stipule-like structures. Flowers: Solitary, borne in the axils of one or both opposite leaves; pedicels 8-22 mm long, bearing 2 bractlets at the apex just below the calyx, these resembling the calyx segments; calyx segments 5, connate at the base, lanceolate, 3.2-5.5 mm long, often elongating in fruit; corolla tubular, 7-10 mm long, yellow with dark veins, pilose within, the 5-lobed limb white to pale lavender; stamens 2, included within the corolla; flowers June- August. Fruits: Septicidal capsule, ovoid-spherical, about 3 mm long, membranous; seeds numerous, dark brown. Ecology: Wet habitats, pond and lake margins, often in mud or submerged; 2100-3000 m (7000-10000 ft); Apache, Coconino, Graham, and Santa Cruz counties; Canada, north-central, western, and southwestern U.S. Notes: Limosella acaulis (Owyhee mudwort) is often difficult to distinguish from L. aquatica; it has smaller, narrower leaves (6-12 mm long) that are less spoon-shaped toward the apex, longer styles, and smaller corolla lobes, but these characters are often found in typical L. aquatica. It occurs in similar habitats. Editor: Springer et al. 2008