Kidneyleaf Mudplantain

Plants annual or facultatively perennial. Vegetative stems submersed with elongate internodes, or emersed and procumbent. Flowering stems 1–9 cm, distal internode 0.5–4 cm. Sessile leaves forming basal rosette, blade linear to oblanceolate, thin, 2.4–3.7 cm × 3–8 mm. Petiolate leaves floating or emersed; stipule 1–5 cm; petiole 2–13 cm; blade reniform, 1–4 × 1–5 cm, length equal to or less than width, apex obtuse. Inflorescences spicate, 2–8-flowered, elongating in 1 day, usually shorter than spathes, terminal flower sometimes extending beyond spathe apex; spathes 0.8–5.5 cm, glabrous; peduncle 0.5–4.2 cm, glabrous. Flowers opening ca. 3 hours after sunrise, wilting by early afternoon; perianth white, salverform, tube 5–10 mm, limbs zygomorphic, lobes narrowly elliptic, 3–6.5 mm, distal central lobe with yellow or green region at base, sometimes with distal brown spot; stamens unequal, lateral stamens 0.9–2.2 mm, filaments linear, pubescent with white multicellular hairs toward apex; central stamen 2.2–4.7 mm, filament sparsely pubescent with multicellular hairs; style pubescent with multicellular hairs. Seeds 8–14-winged, 0.5–0.9 × 0.3–0.5 mm. 2n = 48.

Ala., Conn., Del., Fla., Ga., Ill., Ind., Ky., La., Md., Miss., Mo., N.J., N.Y., N.C., Ohio, Pa., S.C., Tenn., Tex., Va., W.Va.; Mexico; throughout Central America; scattered in South America (Argentina, Brazil, Paraguay); naturalized in Italy.

Flowering Jun--Oct.

Roadside ditches, edges of streams and ponds, freshwater tidal mudflats; 0--2600m.

Heterandra reniformis Ruiz & Pavón Palisot de Beauvois

Heteranthera reniformis R. & P. Fl. Per.
Heterandra reniformis Beativ. Trans. Am. Phil. Soc. 4: 175. 1799.
Heteranthera acuta Willd. Ges. Nat. Freunde Berlin Neue Schr. 3: 438. 1801.
Leptanthus reniformis Michx. Fl. Bor. Am. 125. 1803.
Leptanlhus virginicus Pers. Syn. PI. 1: 56. 1805.
Leptanthus peruvianus Pers. Syn. PI. 1: 56. 1805.
Heteranthera acuta Vahl, Enum. 2: 42. 1805.
Buchosia aquatica Veil. Fl. Flum. 33. 1825.
Heteranthera virginica Steud. Nom. Bot. ed. 2. 2: 29, as synonym. 1841.
Schollera reniformis Kuntze, Rev. Gen. 719. 1891.
Phrynium reniforme Kuntze, Rev. Gen. 3 3 : 318. 1898.
Plant floating or creeping in mud, the stems elongate, branching; leaves erect, the petioles up to 15 cm. long, the blades reniform, or rarely orbicular-reniform, up to 5 cm. wide and 3 cm. long; lower spathe-bract leaf -like, the upper one loosely sheathing, 1-3 cm. long, abruptly caudate; inflorescence spicate, up to 5 cm. long, 2-6-flowered; perianth-tube 6-9 mm long, the limb spreading, white or pale-blue, 8-12 mm. across, its lobes lanceolate, the three outer ones narrower; stamens unequal and dissimilar, the larger one 3 mm. long with linear-oblong anthers, the smaller two 1.5 mm. long with globular anthers; filaments all long-bearded, dilated towards the base; style about the length of the small anthers, pubescent, the stigma appearing capitate, but minutely 3-lobed, papillose; capsule 8-12 mm. long, narrowly conic; seeds columnar, paleyellow-brown, 0.5-0 8 mm. long, 0.3-0.5 mm. wide, 10-winged, the wings evanescent, leaving ridges at maturity.
Type locality: Province of Cercado (now included in Lima), Peru.
Distribution: Connecticut to Nebraska and Texas; Mexico, Central America, and the West Indies; also in South America.

Heteranthera reniformis common name kidneyleaf mud-plantain, and mud plantain; is a plant found in North America. It is listed as a special concern and believed extirpated in Connecticut. It listed as endangered in Illinois and Ohio.