Acid Swamp Yellow Eyed Grass

Xyris serotina is perhaps the most distinctive species of Xyrid over its range. Certainly, it is overall the most scabrous in foliage, and its leaves are unusually long in relation to its scapes.

Herbs, perennial, densely cespitose, 20--60 cm, base thickened. Stems compact. Leaves in fans, 15--20 cm; sheaths straw-colored to dark brown, dull, papillate to rugose, minutely scabrous; blade dull green, flattened, plane, 3--12 mm wide, papillate to minutely scabrous, margins minutely scabrous. Inflorescences: scape sheaths exceeded slightly by leaves; scapes straight, linear, terete, distally slightly compressed or broadly oval, to 2 mm, rugulose, minutely scabrous, strongly 2-ribbed, ribs minutely scabrous; spikes prevalently ovoid to ellipsoid, 8--20 mm, apex acute; fertile bracts 5--7 mm, margins entire, apex shape rounded. Flowers: lateral sepals included, dark brown, slightly curved, 5--7 mm, keel scarious, lacerate; petals unfolding in morning, blade obtriangular, 3--3.5 mm; staminodes bearded. Seeds mealy, ellipsoid, 6 mm, lined longitudinally with papillae, less conspicuously cross-lined. 2n = 18.

Ala., Fla., Ga., Miss., N.C., S.C.

Flowering summer--fall (all year south).

Sands and peats of wet pine savanna, cypress pond edges, bogs, ditches; 0--150m.

Xyris serotina Chapm. Fl. S. U. S. 500. 1860
Tufted or annual; leaves linear, usually 20-35 cm. long, 5-7 mm. broad, obtuse at the apex, tuberculate-scabrid on the margins, elsewhere minutely tuberculate or nearly smooth; sheath occupying about one half the length of the leaf, straw-colored, scabrid, opaque, somewhat dilated at the base; peduncles 40-70 cm. tall, 1.25-2 mm. broad, multicostate above, scabrid on the ridges, the peduncular sheath usually 10-15 cm. long, chestnut-colored and somewhat shining below; spike many-flowered, ellipsoid or obovoid, 10-16 mm. long, usually 5-7 mm. thick, the outer barren bracts broadly elliptic, 2.5—3 mm. long, rounded at the apex, the flowering bracts broadly obovate or nearly orbicular, 6-7 mm. long, 4.5-6 mm. broad, entire, tawny or pale-chestnut-colored, with a large, ovate, usually grayish-green dorsal area 2.5-3 mm. long; lateral sepals narrowly lanceolate-linear, about 5 mm. long and 0.6 mm. broad, acute at the apex ; keel narrow and entire below, somewhat broader and shortly laceratefimbriate from the middle to the apex; seeds ellipsoid, about 0.5 mm. long.
Type locality: Pine-barren swamps, western Florida. Distribution: Florida to Mississippi.

Xyris serotina, the acidswamp yelloweyed grass, is a North American species of flowering plants in the yellow-eyed-grass family. It grows on the coastal plain of the southeastern United States from eastern Louisiana to the Carolinas.

Xyris serotina is a perennial herb with a stem up to 60 cm (2 feet) tall with long, narrow leaves up to 20 cm (8 inches) long.