Scientific name: Sparganium angustifolium Michx.
Common name: Floating Bur-reed
Description
Habit: Glabrous, aquatic or semi-aquatic, rhizomatous, herbaceous perennials rooted in mud; stem submerged or floating, up to 1m.
Leaves: Alternate, simple, entire, sessile, linear, floating, without stipules, 6mm wide; base somewhat inflated, not keeled.
Flowers: Monoecious, actinomorphic; in a terminal spike, raceme or panicle of globose unisexual heads, the upper 2 contiguous heads exclusively male, the lower, larger 2-4 stalked heads exclusively female; perianth represented by 3-6 scales; male flowers with 3-8 stamens; female flowers with 1-2(-3) fused carpels with as many cells, ovules, stigmas and styles, stigmas linear to subcapitate.
Fruits: Fruit a drupe, small, dry, spongy, ellipsoid, shortly pedicellate, style straight, brown; with 1-2(-3) seeds.
Habitat: Rivers and lakes, mainly in mountain districts.
Distribution: Occasional in the West, rare elsewhere.
Native status: Native
Of conservation interest: No