[*] Flowers in bractless one-sided scorpioid spikes.
H. Europæ̀um, L. Erect annual (6–18´ high), hoary-pubescent; leaves oval, long-petioled; lateral spikes single, the terminal in pairs; calyx spreading in fruit, hairy.—Waste places, southward; scarce. (Adv. from Eu.)
1. H. Curassávicum, L. Apparently annual, glabrous; stems ascending; leaves lance-linear or spatulate, thickish, pale, almost veinless; spikes in pairs.—Sandy seashore, Va.; saline soils, S. Ill., and south and westward.
[*][*] Inflorescence not at all scorpioid; flowers scattered.
2. H. tenéllum, Torr. A span to a foot high, paniculately branched, slender, strigose-canescent; leaves narrowly linear, with revolute margins; flowers often bractless.—Open dry ground, Ky. to Mo. and Kan., south to Ala. and Tex.
§ 2. EÙPLOCA. Fruit didymous, the 2 carpels each splitting into two 1-seeded nutlets; style elongated; flowers scattered, large.
3. H. convolvulàceum, Gray. Low annual, strigose-hirsute and hoary, much branched; leaves lanceolate, or ovate or even linear, short-petioled; flowers opposite the leaves and terminal; corolla 6´´ broad, the strigose-hirsute tube about twice as long as the linear sepals.—Sandy plains, Neb. to W. Tex. A showy plant, with sweet-scented flowers.
§ 3. TIARÍDIUM. Fruit 2-lobed, separating into two 2-celled 2-seeded carpels, with sometimes a pair of empty false cells; style very short; flowers in bractless scorpioid spikes.
H. Índicum, L. Erect and hairy annual; leaves petioled, ovate or oval and somewhat heart-shaped; spikes single; fruit 2-cleft, mitre-shaped, with an empty false cell before each seed-bearing cell. (Heliophytum Indicum, DC.)—Waste places, along the great rivers, from S. Ind. to Mo., and southward. (Adv. from India.)
2. CYNOGLÓSSUM, Tourn. Hound's-Tongue.