15. Pogostemon auricularius (Linnaeus) Hasskarl, Tijdsch. Nat. Geschied. 10: 127. 1843.
水珍珠菜 shui zhen zhu cai
Mentha auricularia Linnaeus, Mant. Pl., ed. 1, 81. 1767; Dysophylla auricularia (Linnaeus) Blume; M. foetida N. Burman.
Herbs annual. Stems 0.4-2 m tall, prostrate basally, rooting at nodes, ascending, apex much branched, densely yellow spreading hirsute. Petiole rarely to 1.2 cm, upper stem leaves subsessile; leaf blade oblong to ovate-oblong, 2.5-7 × 1.5-2.5 cm, yellow strigose, with scattered impressed glands, base rounded to shallowly cordate, rarely cuneate, margin serrate, apex obtuse to acute; lateral veins 5- or 6-paired, conspicuous abaxially. Spikes 6-18 cm, apex caudate-acuminate, ca. 1 cm in diam. in flower, continuous or sometimes interrupted at base; bracts ovate-lanceolate, as long as corolla, margin strigose. Calyx campanulate, ca. 1 × 1 mm, glabrous, yellow glandular; teeth broadly triangular, ca. 1/4 as long as calyx tube, margin pilose. Corolla purplish to white, ca. 2.5 × as long as calyx, glabrous. Stamens much exserted, exserted parts bearded. Nutlets brown, subglobose, ca. 0.5 mm in diam., glabrous. Fl. and fr. Apr-Nov.
Wet areas in sparse forests, streamsides; 300-1700 m. Fujian, Guangdong, Guangxi, Jiangxi, Taiwan, Yunnan [Cambodia, India, Indonesia, Laos, Malaysia, Myanmar, Philippines, Sri Lanka, Thailand, Vietnam].