Pogostemon quadrifolius (Benth.) Kuntze (1891: 530)

YAO, GANG, DENG, YUN-FEI & GE, XUE-JUN, 2015, A Taxonomic Revision Of Pogostemon (Lamiaceae) From China, Phytotaxa 200 (1), pp. 448-450 : 448-450

Phytotaxa 200 (1) © 2015 Magnolia Press • 27 18. Pogostemon quadrifolius (Benth.) Kuntze (1891: 530) . Dysophylla quadrifolia Bentham (1830: 30) . Mentha stellata Buch. -Ham. ex Roxburgh (1832: 5), nom. illeg. non Mentha stellata Loureiro (1790: 360) . Eusteralis quadrifolia (Benth.) Panigrahi (1976: 478) . Anuragia quadrifolia (Benth.) Raizada (1976: 218) . Lectotype (here designated):— INDIA. No locality, no date, W. Roxburgh s.n. (K!, isolectotype BM!).

Perennial herbs, 20–50 cm tall. Stems erect, soild, terete, woody basally, upward densely hirsute, branched sometimes upward. Leaves opposite or mostly 3–4 in whorls; petiole ca. 3–5 mm long, densely silky; blades linear, or rarely linear-lanceolate, 3–6.5 cm × 3–6 mm, adaxially appressed silky, abaxially densely so along veins and glandular, base cuneate, margin shallow serrate except base 1/2 entire, apex acuminate, midvein elevated abaxially, lateral veins 2–4 pairs, conspicuous abaxially. Spikes terminal, 4.5–12.5 cm × 4–6 mm, black when dry, compact. Bracts and bracteloes linear, equivalent or slightly longer than calyx, densely silky. Calyx campanulate, ca. 2 mm long, hairy outside, glabrous inside; teeth 5, 0.4–0.5 mm long, triangular to narrowly triangular, hairy outside, glabrous inside, margin ciliate. Corolla purple, black when dry, ca. 3.3 mm long, exserted, subequally 4-lobed, lobes ca. 0.9 mm wide, hairy outside. Stamens 4, much exserted; filaments black when dry, equally hairy at base, inserted at a height of 1.4 mm in the corolla tube; anthers 1-locular, cell apex dehiscent; style ca. 4.5 mm long; stigma bifid, lobes subequal, 0.9–1 mm long. Nutlet 3–4, ca. 0.5 mm long, ellipsoid-oblong, dark brown, spinulose.

Distribution and habitat:— The species is distributed from India, Bangladesh to Myanmar and China. In China, it occurs in southern Yunnan. It grows occasionally near roads at the edge of forests, at an elevation of about 500 m.

Phenology:— Flowering from September to October.

Taxonomic notes:— Pogostemon quadrifolius resembles P. falcatus , the distinguishing characters are discussed under P. falcatus .

IIIb. Pogostemon sect. Verticillati (Benth.) Panigrahi (1984: 102) . Dysophylla sect. Verticillatae Bentham (1833: 157) . Type: D. verticillata Benth. [= Pogostemon stellatus (Lour.) Kuntze ]

Pogostemon sect. Eusteralis (Raf.) Keng (1978: 352) . Eusteralis Rafinesque (1837: 95) . Type: Eusteralis pumila Rafinesque (1837: 95) [= Pogostemon stellatus (Lour.) Kuntze ]