Arrowhead - Sessile-fruited Arrowhead
Sagittaria rigida Pursh
Alismataceae (Water-Plantain) Family

This member of the arrowhead group is found in lakes, fresh and brackish tidal river shores, backwaters and pools. Its preferred habitat in our region is brackish or salt marshes and flats, floodplain (river or stream), fresh tidal marshes or flats, margins of lakes and ponds, shores of rivers and lakes, and swamps. Distribution is generally coastal. It differs from other arrowhead species by its lobe-less leaves, stalk-less fruits and its snowy white flowers.

The leaves are basal (growing only at the base of the plant). The leaf blade shape is cordate (heart-shaped with backward-facing rounded lobes), or sagittate (arrow-shaped with backward-facing pointed lobes). The blade is elliptic (widest near the middle and tapering at both ends), lance-like with more or less parallel sides, or linear, oblong or ovate - extremely variable.

The flower petals are white and measure about 3/4 inch, fused perianth parts are separate. Flowers are presented in raceme (long unbranched stem with stalked flowers growing along it). The ovary is above the point of petal and/or sepal attachment.

Fruit is achene (dry, usually 1-seeded, and does not separate or split open at maturity.

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