Sagittaria latifolia.Elaine Haug @ USDA-NRCS PLANTS Database (Accessed 4/2014).

Sagittaria latifolia is a perennial aquatic herb, monocotyledon, sap milky, rooted in mud, colonial from rhizomes with edible tubers. 

Leaves all basal, 5-40 cm long, 1-25 cm wide, arrow-shaped to elliptic on same plant, very variable, often very narrow with long lobes at base, veins prominent, radiating from insertion of stem. 

Flowers white; monoecious (usually), with 2-10 whorls of showy, 3-parted flowers, about 3 cm wide, staminate flowers above pistillate, 3 petals, stamens yellow, numerous; blooming July-Sept.; flowering stem to 1 m. 

Fruit dry, a ball-shaped head of flat, asymmetrical winged achenes (1-seeded fruit), each about 0.3 cm long; wing is spongy (use lens), probably adapted for floating rather than wind dispersal (pers. obs.). 

Wetland status: OBL. 

Frequency in NYC: Infrequent. 

Origin: Native. 

Habitat: Open wet areas and sunny pond edges. Sometimes planted in wetland restorations and mitigations.  

Alisma subcordatum, plant. Dan Busmeyer, Illinois Natural History Survey. Illinois Plan Information Network. wwx.inhs.illinois.edu (Accessed 7/2017).

Alisma subcordatum is a perennial monocotyledon herb, colonial from rhizomes rooted in mud, flower stem triangular. 

Alisma subcordatum leaves. ©2006 Jeffrey Pippen. 060907-5088butnerz. jeffpippen.com (Accessed 7/2017).

Leaves alternate, elliptic 3-18 cm long, 2-12 cm wide, secondary veins conspicuous, almost parallel to midrib. 

Flowers white, petals 3, about 0.2 cm long, 3 sepals, in widely branched, pyramid-shaped clusters, branches whorled, July- Aug. 

Fruit dry, 0.2 cm in donut-shaped cluster above persistent sepals, dispersed into water in autumn. 

Alisma-subcordatum flower close-up. ©2006 Jeffrey Pippen. 060907-5083butnerz. Noorth Carolina Wildflowers Shrubs & Trees. jeffpippen.com (Accessed 7/2017).

Wetland status: OBL. 

Frequency in NYC: Occasional. 

Habitat: Open sites in shallow water, pond edges, marshes; soil pH 5-7.