Sp. Pl. 2: 601. 1753
Herbs, perennial, terrestrial; rhizomes fleshy, vertical. Stems erect, terete proximally, 4-angled distally, glabrous or puberulent. Leaves cauline, opposite, decussate; petiole present; blade not fleshy, margins crenate-serrate, venation pinnate. Inflorescences terminal, sometimes axillary at distal nodes, spikelike racemes, long-pedunculate, elongate; bracts present. Pedicels present, shorter than calyx; bracteoles present. Flowers opposite, proximalmost sometimes subopposite, erect in bud, becoming horizontal to ascending at anthesis and strongly reflexed and appressed in fruit; sepals 5, calyx bilaterally symmetric, narrowly campanulate, lobes triangular or subulate-uncinate; petals 5, corolla lavender to purple to white, bilaterally symmetric, bilabiate, narrowly campanulate, abaxial lobes 3, adaxial 2; stamens 4, included, filaments glabrous, staminode 0; ovary 1-locular, placentation basal; stigma 2-lobed. Fruits achenes, enclosed in accrescent calyx. Seeds 1, yellowish brown or brown, narrowly ellipsoid, wings absent. x = 14.
c, e North America, e Asia.
The name lopseed alludes to the fruit appearing to lop or hang as it matures, reflexes, and becomes appressed to the infructescence axis.
Phryma has often been included in Verbenaceae based on presumed affinities with members of Lantaneae Endlicher, particularly Stachytarpheta (H. L. Whipple 1972). Others have placed it in Phrymaceae based on its unusual gynoecium with only one ovule becoming a seed. Molecular evidence (P. M. Beardsley and R. G. Olmstead 2002; B. Oxelman et al. 2005) suggests that Phryma is allied with genera traditionally placed in the Scrophulariaceae (Mazus, Mimulus, and others). This evidence has led to an expanded circumscription of Phrymaceae, followed here.