1. Xyris L. (yellow‑eyed grass)
annual or perennial, usually stemless, the base usually somewhat bulbous.
Leaves in basal rosettes, linear or narrowly oblanceolate, the bases flaring
abruptly into a short sheath. Inflorescences long‑stalked, dense,
conelike spikes, the flowers partially enclosed by bracts, these brown, broad,
leathery or papery, overlapping. Flowers perfect, open for less than a day.
Sepals 3, the outer one membranous, deciduous at flowering, the inner pair
membranous to papery, persistent, clasping the fruit, boat‑shaped,
strongly keeled, the keel crested with a hairlike fringe or irregularly and
unevenly toothed. Corollas yellow (white or blue elsewhere), actinomorphic, of
3 petals, these long‑clawed at the base and with a broadly triangular
blade, the apex subentire to shallowly toothed. Stamens 3, opposite the petals
and fused to the petal bases. Staminodes 3, alternating with the petals, the
basal portions flattened, branching apically into 2 ciliate lobes. Carpels 3,
fused, the ovary superior, with 1 locule, the style 3‑branched in the
apical 1/3–1/2, the stigmatic areas truncate. Fruits capsules, enfolded by the
2 persistent sepals and mostly hidden by the bracts. Seeds numerous, minute.
About 240 species, nearly worldwide, especially in the tropics.
seeds of many of the species in this genus are eaten by waterfowl.