44? 
1. XYRIS Gronov. (YELLOW-rYED-GRASS. ) 
Perennials, with yellow flowers solitary in the axils of coriaceous 
scale-like bracts which are densely imbricated in a head, the two lat- 
eral sepals glumaceous and keeled and enclosing the third membran- 
aceous one, 3-clawed petals, 3 fertile stamens (with linear anthers) in- 
serted on the claw (the 3 alternate ones sterile), 3-cleft style, and ob- 
long pod with 3 parietal placenta. 
* Keel of lateral sepals fringed with hairs. 
1, X. ambigua Beyr. Scape 6 to 9 dm. high, slightly twisted, furrowed, 2-edged 
above: leaves linear-lanceolate (1.5 to 3 dm. long), smooth and shining: spikes 
ovate-lanceolate, oblong or cylindric, many-flowered: bracts convex, light brown: 
lateral sepals lanceolate, shining, the upper two-thirds of the narrowly winged keel 
fringed and tapering at both ends. (Y. stricta Chapm.)—Hardin and Austin Counties. 
2, X. flexuosa Muhl. Scape 3 to 4 dm. high, twisted or spiral, 2-edged above 
from somewhat bulbous root: leaves linear, twisted: spike globose, few-flowered: 
lateral sepals linear, curved, fringed the whole length of the wingless keel. (X. scabra 
Engelm. )—Eastern Texas. 
** The winged keel of the lateral sepals toothed or fimbriate. 
3. X. iridifolia Chapm. Scape 5 to6 dm. high, stout, 2-edged and flattened 
above: leaves broadly linear, acuminate, 3 to 6 dm, long: spikes oval or oblong, 
many-flowered: seales dark, thick, convex, with entire margin: lateral sepals 
rather stout, linear, thin, the winged keel irregularly incised-fimbriate throughout 
its length.—From Houston to the mouth of the Brazos, 
4, X. fimbriata ll. Scape 6 to 12 dm. high, straight, twisted, 2-edged above: 
leaves long, broadly linear (3 to 6 dm. long), acuminate: spike cylindric or globose, 
many-tlowered: scales broader above the middle, with entire margin: lateral sepals 
long-linear, long-fimbriate above the middle.—Hockley. 
5, X. torta Smith. Scape 3 to6 dm. high, spirally twisted, l-edged, from bulb- 
ous shining roots: leaves linear (2 to 4 dm, long), twisted: spikes cylindric, 
pointed: scales light brown, twice as long as wide, serrulate at apex: lateral sepals 
linear, exserted, the upper portion of the keel-wing short-fimbriate.—Hempstead. 
6. X. Baldwiniana R. & 8. Scape slender, 2 to 4 dm. high: leaves filiform (1 to 
2 dm. long), hollow, twisted, acute: spikes globose or oval: scales round, the outer 
margin usually lacerate: lateral sepals linear, the upper half of the keel-wing 
serrate, (X. lenuifolia and X. setacea Chapm.)—From Hempstead to Hardin County, 
MAYACEZX. (MAYACA IAMILY.) 
Moss-like densely leafy aquatic plants, with narrowly linear sessile 
pellucid leaves, axillary naked peduncles terminated by a solitary 
perfect 3-androus flower, herbaceous calyx, white corolla, and a3-valved 
1-celled several-seeded pod. 
1. MAYACA Aunblet. 
Creeping or floating in shallow water, with 1-nerved entire (notched 
at apex) leaves, solitary peduncles sheathed at base, persistent peri- 
anth of 3 herbaceous lanceolate sepals and 3 obovate petals, alter- 
nate stamens, ovary with 3 parietal few-ovuled placenta, filifom style, 
and simple stigma. 
1. M. Michauxii Schott & Endl. Peduncles not much exceeding the leaves, 
nodding in fruit,—Extending into Texas from the South Atlantic and Gulf States. 
