This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol3", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
Phyrma Leptostachya L. Sp. Pl. 601. 1753.
Puberulent; stem 1 1/2°-3° high, somewhat 4-sided, sometimes constricted above the nodes, branched above, the branches slender, elongated, divergent. Leaves ovate, acute or acuminate at the apex, obtuse of narrowed at the base, very thin, coarsely dentate, 2'-6' long, the lower petioled, the upper often nearly sessile; spikes very narrow, 3'-6' long; flowers about 3" long, mostly opposite, distant, borne on very short minutely 2-bracteolate pedicels, at first erect, soon spreading, the calyx, after flowering, abruptly re-flexed against the axis of the spike.