keys to the vascular plants of east texas - Botanical Research ...

1144 XYRIDACEAE/XYRIS
Xyris jupicai Rich., (derivation unknown), RICHARD’S YELLOW-EYED-GRASS, YELLOW-EYED-GRASS.
Plants solitary or in small tufts, annual or rarely biennial, lacking in red pigmentation; leaves
10–60 cm long, 3–10 mm wide, erect or ascending in narrow fans; scapes 20–70(–90) cm long;
spikes 5–15(–25) mm long; seeds 0.4–0.5 mm long, faintly ribbed. Wet sands, sandy peat, alluvium
of roadside ditches, flatwood pond margins, cypress swamps, lakeshores, and particularly
in mechanically disturbed wetlands; widespread in Pineywoods and Post Oak Savannah;
also Gulf Prairies and Marshes; se U.S. from NJ s to FL w to OK and TX. Flowers opening in the
morning; Jun–Aug. Kral (1966a; 1979a; pers. comm.) considers this species to probably be adventive
from Latin America (Mexico, West Indies, Central and South America). Kral (2000a) noted
that it frequently shares habitat with two related species, X. difformis var. difformis and X.
laxifolia. He commented, “It differs from both in its lack of red pigmentation, from X. difformis
by its more erect leaves and narrower, less prominently ribbed scapes, and from X. laxifolia by its
narrower leaves and scapes, shorter, narrower, paler spikes, and translucent (rather than mealy),
shorter seeds.” See further discussion under X. difformis var. difformis and X. laxifolia. I
Xyris laxifolia Mart. var. iridifolia (Chapm.) Kral, (sp.: loose-leaved; var.: iris-leaved), IRIS-LEAF
YELLOW-EYED-GRASS. Perennial, solitary or in small tufts, not bulbose at base; leaves 40–70 cm
long, 10–25 mm wide; scapes 60–90 cm long, to 3–4 mm wide; spikes (15–)20–35 mm long;
seeds farinose (= mealy), 0.7–0.9(–1) mm long. Wet sands, wet sandy clay, sandy peat, peat muck,
alluvium of stream banks, cypress swamps, marshes, and pineland pond margins, the base of
the plant commonly submersed; widespread in Pineywoods and Post Oak Savannah; also n
margin of Gulf Prairies and Marshes; se U.S. from VA s to FL w to OK and TX. Flowers opening
in the morning; Jul–Sep. [X. iridifolia Chapm.] This and X. stricta are the only East TX Xyris
species with farinose seeds. According to Kral (2000a), “It differs [from the similar X. jupicai] in
having taller, wider foliage and scapes, in the leaf sheaths being reddened (rather than greenish
or straw-colored), in the larger, longer, thicker, darker spikes, and in the longer, mealy (rather
than translucent) seeds. Scape ribs in X. jupicai are papillate distally; those of X. [laxifolia var.]
iridifolia are smooth.” The type variety, Xyris laxifolia var. laxifolia, is a common wetland
plant in Central and South America (Kral 2000a).
Xyris platylepis Chapm., (broad-scaled), TALL YELLOW-EYED-GRASS, YELLOW-EYED-GRASS. Perennial,
solitary or in small tufts, bulbose-based; leaves (15–)20–40(–50) cm long, (3–)5–10 mm
wide; scapes 50–110 cm long; spikes 15–30(–40) mm long. Sands or sandy peats, pineland pond
margins, savannahs, bogs, ditches, stream banks, and other moist sites, but seldom if ever on
inundated areas, rather weedy; Jasper (BRIT), Newton (BRIT, VDB), Sabine (BRIT, MacRoberts &
MacRoberts 1998a), Tyler (Bridges & Orzell 1989a), and Angelina (Turner et al. 2003) cos. in the
se part of the Pineywoods, typically on the Catahoula geologic formation; se U.S. from VA s to
FL w to TX. Flowers opening in the afternoon; summer. According to Kral (1966a), “This species,
because of its coloured [sic], fleshy and scale-like leaf bases, could be confused with X. torta or
X. scabrifolia. From the former it is distinguished by its lacerate sepal keels; from the latter it is
distinguished by its smaller seed and its smooth leaf and scape surfaces.” Kral (2000a) also
noted, “Xyris platylepis, which may be associated with other bulbose-based species such as X.
torta and X. caroliniana, appears very similar to larger extremes of the former but differs in its
plane (rather than prominently ribbed) leaf surfaces and its lacerate (rather than ciliate) sepal
keels, and from the latter in its more shallowly set and pinkish or red (rather than chestnut
brown) bases, as well as in its sepal keels that are lacerate rather than fimbriate.”
Xyris scabrifolia R.M. Harper, (rough-leaved), ROUGH YELLOW-EYED-GRASS, HARPER’S YELLOW-
EYED-GRASS, ROUGH-LEAF YELLOW-EYED-GRASS. Perennial, solitary or in small tufts, bulbosebased
or nearly so; leaves 10–40(–50) cm long, 2.5–10 mm wide; scapes 30–60 cm long; spikes
10–20 mm long. Moist to wet sandy peats of hillside acid sphagnous bogs or sandy seepage areas
in pinelands; Angelina, Jasper, Newton, and Sabine (BRIT, VDB) cos. in the se part of the
Pineywoods, and reported from Henderson Co. (Poole et al. 2002) and Wood Co. (Bridges &