American water horehound, more...
[Lycopus americanus var. longii Benner, more]
Plant: perennial, rhizomes ± slender, not thickened at tip; stems erect, 2-8 dm, generally glabrous; nodes short-hairy Leaves: 2-8(10) cm, short-petioled, oblong to lanceolate, lobed to cut especially in lower half, glabrous to puberulent on veins INFLORESCENCE: cyme, axillary, each head-like, subtended by leaves Flowers: calyx 5-lobed, lobes awl-like, short-awned; corolla 2-3 mm, ± = calyx, white; stamens 2, exserted, staminodes 2, minute, club-shaped; style exserted Fruit: nutlets 4, 1-1.5 mm, top rounded, smooth, ± compressed, edge corky-thickened Misc: Moist areas, marshes, streambanks; < 1000 m.; Aug-Sep
Rhizomes elongate, without tubers; lvs glandular- punctate and usually glabrous (or scabrous above) except along the veins beneath, where provided with short hairs only 0.1-1.5 mm, the blade lanceolate or narrowly oblong to nearly linear, 3-8 cm, tapering to a short petiole or narrow, subpetiolar base, coarsely and irregularly incised-toothed or subpinnatisect, the lower teeth the larger; bracts lanceolate and about equaling the cal, avg 3 mm; cal 2-3.3 mm, its 5 lobes narrow, firm, slenderly subulate-pointed, surpassing the nutlets; cor 4-lobed, the upper lobe broader and notched; anthers 0.25-0.5 mm; nutlets 1.0-1.4 נ0.7-1.0 mm, the outer apical margin smooth and broadly rounded, the corky lateral ridges confluent around the tip, the inner angle much shorter than the outer ones, so that the center of the set of nutlets is depressed; 2n=22. Our most abundant sp.; Nf. and Que. to B.C., s. to Fla. and Calif.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
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