The common name of this plant is beaked spike-rush. More precisely
it can be translated from Latin as "spike-rush with a small
beak." Differently from many other spike-rushes, in this one the fruit
(achene) is seamlessly connected with the narrow tubercle (a sort of a cap on
top of the fruit), the entire structure resembling a bird's head with a
beak. The achene is three-sided (trigonous). The bristles surrounding
the achene are what spike-rushes have for "flower petals"--the
perianth. They are barbed downward (retrorsely). The length of the achene
together with the beak is about the same as the length of the bristles.