Intro: Erect to leaning, rhizomatous perennial of freshwater tidal marshes, floodplain forests and alluvial swamps, sandy/gravelly bars and shores.

Stems: Stems 4-angled and ridged, simple or extensively branched, smooth or sparingly hairy.

Leaves: Leaves opposite, petiolate, lance- to elliptic-lance-shaped, 1 1/4-3 in. long, deeply toothed (less so in upper leaves), minutely hairy on veins beneath.

Inforescence:

Flowers: Flowers in small, axillary heads. Each flower white, less than ¼ in. long, short-tubular and opening to 4 spreading lobes. The light green, tubular, 5-lobed calyx is shorter than the corolla, and there are 2 protruding stamens.

Fruits: Fruit a set of 4 nutlets forming a square inside the persistent calyx; calyx lobes exceed the nutlets.

Comments:

Height: 1-3 ft.

plant sale text:

bloom table text:

description: Erect to leaning, rhizomatous perennial of freshwater tidal marshes, floodplain forests and alluvial swamps, sandy/gravelly bars and shores.

stems: Stems 4-angled and ridged, simple or extensively branched, smooth or sparingly hairy.

leaves: Leaves opposite, petiolate, lance- to elliptic-lance-shaped, 1 1/4-3 in. long, deeply toothed (less so in upper leaves), minutely hairy on veins beneath.

inflorescence:

flowers: Flowers in small, axillary heads. Each flower white, less than ¼ in. long, short-tubular and opening to 4 spreading lobes. The light green, tubular, 5-lobed calyx is shorter than the corolla, and there are 2 protruding stamens.

fruits: Fruit a set of 4 nutlets forming a square inside the persistent calyx; calyx lobes exceed the nutlets.

comments:

cultural notes:

germination code:

native range: North America