Stenanthium (A. Gray) Kunth, Enum. Pl. 4: 189. 1843, nom. cons.
Perennial herbs, usually with raphides and saponins; with tunicate bulb. Stem single, erect, glabrous. Leaves mostly basal and progressively reduced upwards on stem to small linear bracts (plants often appearing scapose), spirally arranged, simple, narrowly linear to oblanceolate, lorate, sheathing at base, acuminate or obtuse at apex, entire, glabrous; venation parallel; stomata anomocytic, usually on abaxial side only (rarely also on adaxial surface). Inflorescence paniculate or racemose, polytelic, terminal. Flowers 3-merous, actinomorphic, perfect and also often terminal flowers on inflorescence branches staminate (then plants andromonoecious), semi-epigynous, pedicellate, bracteate, ascending or pendulous] ± rotate or campanulate, protandrous. Tepals 6, distinct to very briefly basally connate, biseriate, narrowly lanceolate to linear-oblong, apex acute to acuminate, spreading or reflexed, petaloid, white, green, purplish, greenish yellow, greenish brown, purplish brown ("bronze") to deep brown or purplish black, non-glandular or with bilobed adaxial tepal nectaries, imbricate, persistent. Stamens 6 in 2 whorls, barely or distinctly epitepalous; filaments distinct, equal [unequal]; anthers basifixed, 1 locular (thecae confluent), cordate or reniform, dehiscing by valves opening into a peltate disc, extrorse; pollen grains ellipsoid, 1 sulcate, sculpturing reticulate. Gynoecium 3 carpellate, weakly syncarpous (weakly appressed/apocarpous, at least above); ovary one-fifth to half-inferior, 3 locular, deeply 3 lobed; placentation axile to parietal; ovules numerous, anatropous or campylotropous, bitegmic; styles 3, distinct, relatively stout, with stylar canals, spreading to recurved, persistent; stigmas adaxial/terminal, obscure; rudimentary ovary present in staminate flowers. Fruit a septicidal (ventricidal) capsule. Seeds flat, narrowly ellipsoid, angled or distinctly winged; endosperm development unknown; embryo small; endosperm copious.
Base chromosome numbers 8, 10. (Including Stenanthella Rydb.). Type species: S. angustifolium (Pursh) Kunth (Veratrum angustifolium Pursh = Stenanthium gramineum (Ker-Gawl.) Morong ); the only species in the protologue; basionym: Veratrum subg. Stenanthium A. Gray. (Name from Greek stenos, narrow, and anthos, flower, in reference to the narrow tepals.)