Eragrostis cilianensis (All.) Janch., stinkgrass. Annual, fibrous–rooted, several–stemmed at base, shoots decumbent to ascending, in range to 38 cm tall; shoots with only cauline leaves, to 6 leaves per shoot, stem bent at each node (geniculate), having small, craterlike glands on leaves and inflorescence, somewhat odorous when crushed
Stems (culms) cylindric, to 2 mm diameter, smooth, glabrous, at top of culm below the lowest branch of inflorescence having a set of craterlike glands; internodes hollow.
Leaves alternate distichous, simple with sheath; sheath open and > 360° at base, < 80 mm long, < internode, somewhat keeled, conspicuously pilose–ciliate on margins from below midsheath, without lobes (auricles) at top, having a vertical row of craterlike glands along keel base–to–top and often along several principal veins approaching top, at top with pilose hairs to 4 mm long; ligule of white hairs, to 1 mm long; collar on outer surface short–hairy next to long hairs of sheath; blade linear, < 100—270 × < 4—8 mm, the widest near the base, the longest blade just below flag leaf, flat when fresh and finely striped, minutely serrate and with craterlike glands on margins, parallel–veined with veins slightly raised on upper surface, having micropapillate along veins and somewhat scabrous especially above midblade.
Inflorescence spikelets, in terminal, open, ovoid panicle, with ascending lateral branches, each branch often with 8 spikelets, each lateral branch and wavy minor axis with pulvinus in axil, spikelets having 7—15+ florets (fewer when young), stalk of spikelet (pedicel) mostly 1—3 mm long, < spikelet, with 1—2 glands on stalk within 1 mm of spikelet.
Spikelet initially ovate compressed side–to–side, at flowering 5—8 mm long, membranous with set of parallel green veins on each side (lemma), lemma sometimes aging purplish; rachilla internodes 0.5 mm long; breaking below each floret but with pale persistent along rachilla; glumes 2, subequal, membranous, lower glume membranous with green keel, keel scabrous above midpoint, with 1—2 craterlike glands along keel, upper glume ca. 2.1 mm long, with 3 green veins but lateral veins only to midpoint, keel usually with 2 glands; lemma boat–shaped and keeled, 1—2(—2.6) mm long, width > length, 3–veined (1–veined if short), keel green with 1—3 craterlike glands on exposed portion of keel, later veins green and ca. 0.3 mm from margins; palea 2–veined, membranous, < lemma, 2–keeled with margins strongly folded along green keels, keels short–ciliate
Flower perianth (locicules) narrowly wedge–shaped, to 0.2 mm long, colorless; stamens 3, free; filaments fine threadlike, 1.5 mm long, white; anthers dorsifixed, dithecal, 0.5 mm long, pale yellow, longitudinally dehiscent; pollen white; pistil 1, ca. 1.5 mm long; ovary superior, ovoid compressed, ca. 0.5 mm long, greenish, 1–chambered with 1 ovule; styles 2, diverging from top of ovary, threadlike, ca. 1 mm long, colorless–white, stigmatic and ± feathery with short branches above midpoint.
Fruit achene (caryopsis), subspheroid to ovoid, 0.55—0.7 × 0.5 mm, light brown.
A. C. Gibson