Xyris torta - (image 1 of 5)
Taxonomy
Family: Xyridaceae
Habitat
Wet, acid soil.
Associates
Distribution
NH to WI, south to VA, GA, OK, and TX.
Morphology
Herbaceous perennial; leaves rather shallowly set, linear, ascending, mostly 20-50 cm long and 2-5 mm wide, twisted, longitudinally grooved, lustrous dark green, fleshy-thickened at the pale to often purplish or brownish base, some of the outer leaves short and with notably dilated and dark base, the plants thus appearing bulbous; scapes 15-80(-100) cm, more or less twisted, flexuous, and many-ridged below, 2-4(-6)-ridged above and somewhat flattened under the spike; spikes mostly 1-2.5 cm at maturity, many-flowered, ovoid; lateral sepals shortly included, lunate, the broad, thickened keel ciliate-scabrous from near the base to the tip, bearing a small tuft of reddish-brown (seldom pale) hairs at the apex; each bract with a similar tuft of hairs at the apex; petal blades yellow, obovate, 4 mm, unfolding in the morning; seeds 0.5 mm, plump, finely ridged.
Notes
Flowers June to August
Wetland indicator: OBL
This species differs from X. difformis and X. montana in that the leaves are not arranged in a fan and more conspicuously twisted above.
The important feature for identification of Xyris spp. is usually the lateral sepals (specifically the keel) which are obscured by the bracts of the inflorescence in most species, making identification from photographs very difficult. In two species, X. caroliniana and X. fimbriata, the tips of the lateral sepals are fimbriate and surpass the subtending bracts making identification of these easier without dissecting the inflorescence, especially for plants in fruit.
References
Gleason, Henry A. and A. Cronquist. 1991. Manual of Vascular Plants of Northeastern United States and Adjacent Canada. Second Ed.
The New York Botanical Garden. Bronx, NY
USDA, NRCS. 2002. The PLANTS Database, Version 3.5 (http://plants.usda.gov).
National Plant Data Center, Baton Rouge, LA 70874-4490 USA.
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Michael Hough © 2018 |