Pogostemon linearis (Benth.) Kuntze (1891: 529)

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

22. Pogostemon linearis (Benth.) Kuntze (1891: 529) . Dysophylla linearis Bentham (1848: 157) . Eusteralis linearis (Benth.) Panigrahi (1976: 476) . Anuragia linearis (Benth.) Raizada (1976: 218) . Lectotype (designated by Panigrahi 1976: 476): — INDIA. Assam: no locality, no date, J. Mack s.n. (K). Figure 15 .

Annual herbs, to 80 cm tall. Stems hollow, terete, with shallow grooves, erect-ascending, base procumbent and trailing, pubescent, rust colored. Leaves in whorls of 4–6, sessile; blade linear-lanceolate to linear, 2.5–7.5 cm × 2–6 mm, papery, adaxially puberulent, abaxially glandular pubescent on midvein otherwise glandular, base acute,

30 • Phytotaxa 200 (1) © 2015 Magnolia Press

DENG & GE margin entire or obscurely remote serrate toward apex, slightly revolute, apex acuminate. Spike terminal, simple, 2–7 cm × 9–12 mm, continuous; flowers subsessile. Bracts and bracteoles lanceolate to linear, 2.5–4 mm long, apex purple-red, pubescent. Calyx narrowly campanulate, 2.5–2.8 mm long, 5 veined, sparsely pubescent and brown glandular outside, puberulent inside of tube; teeth 5, triangular, suberect, pubescent inside, margin ciliate. Corolla 4–4.2 mm long, much exserted, puberulent outside, subequally 4-lobed, sparsely pubescent and glandular outside. Stamens 4, much exserted; filaments 4.3–4.5 mm long, inserted at a same height in corolla tube, bearded at middle, bearded portion exserted; anthers 1-locular, cell apex dehiscent; style 5–6 mm long; stigma bifid, lobes subequal, 0.7–0.8 mm long; disc ca. 0.3 mm long. Nutlets 4, ellipsoid to ellipsoid-oblong, reticulate-foveate.

Distribution and habitat:— The species is distributed in Bhutan, China, and NE India. In China, it occurs in Yunnan ( Figure 16 ). It is discovered infrequently in wet areas or marsh grounds where with rich organic matter, at the elevation of 1500–2400 m.

Phenology:— Flowering and fruiting from October to December.

Taxnomic note:— The species resembles Pogostemon yatabeanus ( Makino 1898: 55) Press (1982: 74) , but differs from the latter in its stems and leaves with rust colored hairs (not glabrous), and leaves in whorls of 4–6 (not 3–4).

POGOSTEMON ( LAMIACEAE )

Figures

FIGURE 15. A–G. Pogostemon linearis. A. Habit; B. Flower; C. Calyx split; D. Corolla split open with stamens and style; E–G. Bract and bracteole. Drawn by Y.X. Liu based on G. Forrest 25138 (PE).

FIGURE 16. Distribution maps of Pogostemon linearis, P. pentagonus, P. sampsonii and P. stellatus.