Phryma leptostachya is a perennial herb 0.4-1 m tall, erect, few-branched, stems 4-sided, purple, leafy, finely hairy, with a swollen area 0.3-1.2 cm long above each node; roots associated with VA mycorrhizas (Brundrett and Kendrick 1988).
Leaves opposite, each pair at right angles to next (decussate), lower leaf stalks 2-5 cm long, upper leaves often stalkless, blade egg- to lance-shaped, 5-16 cm long, 4-9 cm wide, veins impressed, surface wrinkled (rugose), margin coarsely toothed (Radford et al. 1968; Yatskievych 2006).
Flowers pale purple to white, to 0.8 cm long, corolla tubular, more or less cylindrical, bilaterally symmetrical, 2-lipped, upper lip 0.2 cm long, notched at tip, lower lip 0.2-0.3 cm long, deeply 3-lobed, middle lobe much longer than laterals, lobe tips rounded; calyx tubular, 2-lipped, upper 3-lobed, lobes linear, sharp, almost as long as petal tube, lower lip with 2 very short lobes; stamens 4 shorter than petal tube; ovary superior, stigma 2-lobed; each flower above a small bract; flowers opposite on floral axis, each pair at right angles to next; flower buds pointing upwards, open flowers horizontal, stalk (pedicel) quickly bending downward as fruit forms; inflorescence a spike-like (raceme) 5-20 cm long, often finely hairy, purplish, flower stalks less than 0.1 cm long; blooms June- Aug..
Fruit dry, 1-seeded (achene) to 0.4 cm long, enclosed in persistent, ribbed calyx, to 1 cm long in fruit, calyx lobes becoming hooked at tips; fruits pointing downward against axis; fruit matures Aug-Oct. (Radford et al. 1968; Yatskievych 2006).
Wetland status: UPL.
Frequency in NYC: Very infrequent.
Origin: Native, but another variety found in Asia.
Habitat: Moist, rich woods.
Notes: Phryma is the only species in its genus (monotypic genus). It is sometimes put into the family Phrymaceae, in which case it is the only plant in that family (monotypic family; but see Jung et al. 2005).