Eragrostis lugens Nees, mourning lovegrass. Perennial herb, lacking rhizomes (shoots early separated belowground), fibrous–rooted, cespitose, several–stemmed at base, ascending, in range to 40 cm tall; shoots with basal leaves and several cauline leaves, with straight pilose hairs on parts of shoot and inflorescence, lacking glands.
Stems cylindric and not ridged, to 1 mm diameter, striped green, smooth, usually somewhat bent (geniculate) at cauline nodes, glabrous.
Leaves alternate (distichous), simple with sheath; prophyll at base of each shoot 2–keeled, triangular in outline, to 10 mm long, with folded membranous margins but not keeled, glabrous, minutely scabrous along keels; sheath open, somewhat folded (of flag leaf cylindric), ridged, > internodes, mostly pilose–ciliate on membranous margins but of basal leaves often with appressed straight hairs, especially flag leaf with pilose hairs at top 2—4 mm long, without lobes (auricles) at top; collar pilose–ciliate; ligule fused at base and short–ciliate above, to 0.4 mm long; blade linear, in range to 110 × 3 mm, the widest near midblade becoming inrolled upward when water–stressed, minutely toothed on margins above midblade, long–tapered at tip, parallel–veined with veins finely raised on upper surface and midrib raised on lower surface, upper surface minutely scabrous along veins and with or without widely scattered (sparse) pilose hairs.
Inflorescence spikelets, in open, wispy, terminal panicles, panicle ellipsoid to ovoid, in range to 250 × 140 mm, lateral branches at nodes often 2—3, spreading mostly at 30—45°, spikelet in range with 2—6 florets, bracteate, lacking awns; axes having pulvinus in axil of each lateral branch and branchlet, pulvinus with pilose hairs 2—4.5 mm long; axes of inflorescence ridged and scabrous, stalk of spikelet slender, 3–ridged and somewhat wavy, 1—10 × 0.1—0.15 mm, with green and white stripes, scabrous along ridges, lacking glands.
Spikelet narrowly ovate to lanceolate in outline compressed side–to–side, to 5 × < 1 mm (to 1.3 mm wide during pollination), membranous, straight, rachilla zigzagged but short, remaining intact, having glumes abscising and lemma released with fruit and palea persistent on rachilla; glumes 2, unequal, keeled, lower glume 0.9—1 mm long, upper glume ± 1.5 mm long, 1–veined, minutely scabrous along keel, lacking glands; lemma ovate, keeled, ca. 1.5 mm long, 3–veined, veins green but lateral veins not reaching tip, scabrous along keel; palea arched, 2–keeled, 2–veined, ca. 1.4 mm long, folded along keels, concave on back, rounded at tip between vein ends, minutely scabrous along veins above midpoint.
Flower bisexual; perianth (lodicules) 2, broadly wedge–shaped, 0.25 × 0.25 mm, white; stamens 3, free; filaments threadlike, 0.8—1 mm long, white; anthers dorsifixed, dithecal, in range 0.4—0.45 mm long, rose–purple, longitudinally dehiscent; pollen white; pistil 1, 1.2 mm long; ovary superior, ovoid, 0.3—0.35 mm long, white, 1–chambered with 1 ovule; styles 2, exserted, stigmatic portion bottlebrushlike above midpoint (ca. 0.3 mm long).
Fruit achene (caryopsis), somewhat obovoid, ca. 0.7 × 0.4 mm, opaque brownish, in range lacking groove.
A. C. Gibson