Scientific name: Sparganium natans L.
Common name: Least Bur-reed
Description
Habit: Glabrous, aquatic or semi-aquatic, rhizomatous, herbaceous perennials rooted in mud; stems floating or submerged, up to 10-35cm, with 4-9 internodes.
Leaves: Alternate, simple, entire, sessile, linear, without stipules, limp, thin, usually translucent, floating, 4-5mm wide; the base scarcely inflated.
Flowers: Monoecious, actinomorphic; in a terminal spike, raceme or panicle of globose unisexual heads, the upper 1 contiguous head exclusively male, the lower, larger 2-4 stalkless or shortly 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-obovoid, with a short beak-like style, pale brown, fruiting heads 10mm across.
Habitat: Bogs, drains, canals and peaty lakes.
Distribution: Occasional.
Native status: Native
Of conservation interest: No