6(5). Plant bases greenish, pale to dark-brown or stramineous 7. X. Jupicai. 



6. Plant bases pinkish or purplish (7) 



7(6). Summit of scape not flattened and broad relative to the spike; scape ridges 

 usually more than 3 and therefore the upper scape broadly oval or 

 almost round in oultine (except for projecting ridges); habitats 

 various, usually not alluvial; foliage pinkish- or purplish-based but 

 the surfaces (particularly of the outermost leaves) papillose or 

 tuberculate-scabrid 8. X. difformis var. Curtissii. 



7. Summit of scape quite evidently flattened and broad relative to the spike (at 



least on living specimens); scape ridges few, usually 2 or 3, the 2 

 most prominent ones along the scape edges and therefore the upper 

 scape narrowly ellipsoidal or fusiform in cross section; plants com- 

 monly of wet situations in sun or shade; foliage smooth, a very 

 deep-rich-green except for the reddish or purplish color of the leaf 

 bases (8) 



8(7). The two principal scape ridges noticeably and abruptly flattened and wing- 

 like below the spike and in the plane of the flattened scape, their 

 combined width (on live specimens) broader than the scape, thus 

 the outline of the cross section of the scape bicaudate; fruiting 

 spikes seldom longer than 15 mm., ovoid, acute; seeds translucent, 



ovoid or ellipsoidal, seldom longer than 0.6 mm 



8. X. difformis var. difformis. 



8. The two principal scape ridges not abruptly flattened, the scape itself flattened 



and 2-edged and (in cross section) narrowly elliptic; fruiting spikes 

 seldom shorter than 15 mm., broadly ellipsoidal or oblong, blunt; 

 seeds farinose, dark when ripe, fusiform or narrowly oblong and 

 never as short as 0.6 mm 6. X. iridifolia. 



1. Xyris Baldwiniana Schult. Fig. 298. 



In large tufts, the leaf bases usually brownish, lustrous; leaves filiform to linear- 

 filiform, 1-3 dm. long, straight or slightly twisted, green, expanding more or less 

 abruptly toward the lustrous base; sheath of the scape from one half as long to 

 nearly as long as the principal leaves, tightly investing the scape except for the 

 the loose orifice and a short blade; scape 2-4 (-5) dm. long, usually broader than 

 the leaf, terete below, one-ridged and tending to be terete above; spikes at the 

 seed-bearing time ovoid to ellipsoidal, 4-7 mm. long, acute or blunt, of a few 

 tightly imbricate bracts; fertile bracts ovate to obovate, 4-5 mm. long, not keeled, 

 the apex rounded, the exposed margin entire, becoming erose with age, the matrix 

 dull- to dark-brown or reddish-brown, the dorsal area elliptic and dull-green; 

 lateral sepals included, slightly shorter than the bracts, linear but slightly curvate, 

 reddish-brown, the keel lacerate from the tip to about the middle or slightly be- 

 yond; petal blades cuneate-obovate, about 3-4 mm. long, unfolding in morning; 

 seeds oblong to narrowly ellipsoidal, 0.8-1 mm. long, the longitudinal lines evi- 

 dent, translucent, yellowish or pale-amber. Atypical plants erroneously reported 

 from Texas as X. ElUottii Chapm. 



In moist sands or sandy peats of pine flatwoods, hillside bogs, roadside ditches, 

 and savannahs in e. Tex., May-July; in Coastal Plain, N.C. s. into n. Fla. and w. 

 to Tex. 



Plants now referred here with extremely narrow and flat leaves, apparently 

 the var. tenuifolia (Chapm.) Malme (X. tenui folia Chapm.), could possibly be a 

 hybrid of this species and X. ElUottii Chapm. if it were not for the fact that the 

 latter species is thought not to occur farther west than southern Mississippi. 



2. Xyris ambigua Kunth. 



Solitary or in small tufts, the base hard, often fibrous; leaves broadly linear, 

 spreading, 1-4 dm. long, 3-20 mm. broad, a dark- and lustrous-green above the 



581 



