Xyris brevifolia Michx.

Plants in south Florida and Cuba often have longer and narrower leaf blades than is typical, and G. O. K. Malme (1925) named Cuban material Xyris intermedia on the basis of longer, narrower leaf blades and entire sepal keels. In Florida, however, all of these characters intergrade. The red sepal tips, almost a homology with the bract dorsal area, are a constant (yet neglected) character. This species is often weedy.

Herbs, annual, cespitose, rarely solitary, (4--)10--30(--60) cm. Stems compact. Leaves in fans, 2--10(--15) cm; sheath base greenish to pink; blade green or red-tinged, filiform to linear, 1--4 mm wide, smooth, margins smooth to papillate. Inflorescences: scape sheaths mostly exceeding leaves, blade prominent (in filiform-leaved extremes, overtopped by leaves); scapes wiry, nearly terete, 0.5--1 mm wide, low-ribbed apically; spikes oblate to globose or ovoid, mostly as broad as long, 5--7(--10) mm, apex blunt; fertile bracts 3--6 mm, margins often squarrose, lacerate, scarious, with red inner band, apex broadly rounded. Flowers: lateral sepals included, slightly curved, 3--5 mm, keel firm, nearly entire to papillate or ciliolate, apex reddish; petals unfolding in morning, blade obovate, 2.5--3 mm; staminodes bearded. Seeds amber, broadly ellipsoid, 0.5 mm, finely lined. 2n = 18.

Ala., Fla., Ga., N.C., S.C.; West Indies; South America (Brazil).

Flowering spring--summer(--winter in the south).

Acid, sandy, moist savanna and cleared areas; 0--200m.

Xyris intermedia Malme

Xyris brevifolia Michx. Fl. Bor. Am. 1: 23. 1803
Xyris caroliniana var. brevifolia Wood, Class-Hook ed. 2. 564. 184/ .
Annual (at least often); leaves linear, 2-4 (-5) cm. long, 0.8-1.5 (-2) mm. bre^d, acute on nearly so, smooth or slightly scabrid; sheath occupying one third to one half the length of the leaf, somewhat dilated and rusty at the base; peduncles 15-30 (rarely-40) cm. tall, about 0.5 mm. broad, terete or nearly so, smooth, the peduncular sheath 4-5 cm. kmg, somewhat rusty at the base; spike few-flowered, ellipsoid, obovoid, or nearly globose, 4-5 (-6) mm. long, 2.5-4 mm. thick, the outer barren bracts elliptic, about 3 mm. long, carinate, the flowering bracts elliptic or obovate, 3.5-4.5 (-5) mm. long, 2-3 mm. broad, rounded and lacerate at the apex, obtusely carinate above, rusty-purple at the apex, elsewhere straw-colored or tawny, with a grayish-green or purple lanceolate dorsal area about 3 mm. long; lateral sepals lanceolate, somewhat falcate, 3-4 mm. long, about 0.6 mm. broad, lacerate and often rusty-purple at the apex; keel very narrow, ciliate-seabrid from near the base to the apex, especially in the middle; seeds ellipsoid, about 0.4 mm. long and 0.2 mm. thick.
Type locality: Wet meadows, coastal Georgia.
Distribution: North Carolina to Florida; also in Brazil (Rio de Janeiro; introduced). According to Poiret: Santo Domingo and the Antilles (certainly erroneous).

Xyris intermedia Malme, Ark. Bot. 19 19 : 2. 1925
Tufted; leaves linear, 5 7 mm long, about 1 mm. broad, acute, smooth or with slightly
scabrid margin heath occupying one fourth to one third the length of the leaf, somewhat dilated and rusty at the base; peduncles L5 22 I 28) cm. tall, about 0.5 mm. broad, terete or somewhat compressed, slightly bicostate, smooth orscabrid above on the ridges, the peduncular sheath equaling the leaves, somewhat rusty at the base; spike few-ilowered, obovoid or globose, 4-5 mm. long, 3-5 mm. thick, the outer barren bracts elliptic, about 3 mm. long, rounded a1 the apex, obtusely carinate, the flowering bracts elliptic or obovate elliptic, 3.5-4 mm. long, 2-2.5 mm. broad, entire or nearly so, indistinctly carinate above, tawny, with an ovate-lanceolate dorsal area 1.5-2 mm. long; lateral sepals lanceolate, somewhat falcate, about 3 mm. long and 75 mm. broad, obtuse at the apex or nearly so; keel very narrow, entire or indistinctly scabrid.
Tvn; LOCALITY: 111 sandy pine-woods. Sabalo, Pinar del Rio. Cuba.
Distribution: Known only from the type locality.

Xyris brevifolia, the shortleaf yelloweyed grass, is a North American species of flowering plant in the yellow-eyed-grass family. It is native to Brazil, the West Indies, and the southeastern United States (Florida, Alabama, Georgia, and the Carolinas).

Xyris brevifolia is a perennial herb up to 60 cm (2 feet) tall with narrow leaves up to 15 cm (6 inches) long, and yellow flowers.

Xyris brevifolia là một loài thực vật hạt kín trong họ Hoàng đầu. Loài này được Michx. miêu tả khoa học đầu tiên năm 1803.