Pogostemon cruciatus (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

19. Pogostemon cruciatus (Benth.) Kuntze (1891: 530) . Dysophylla cruciata Bentham (1830: 30) . Eusteralis cruciata (Benth.) Panigrahi (1976: 478) . Anuragia cruciata (Benth.) Raizada (1976: 218) . Lectotype (designated here): — NEPAL. In 1821, N. Wallich 1541 (K-W!, isolectotypes E!, K!, NY!, P!).

Dysophylla tetraphylla Wight (1833: 355) . Type: — INDIA. Probably Malabar, no date, R. Wight 2531 (holotype K; isotype E!).

Annual herbs, 15–45 cm tall. Stems solid, erect, terete, with shallow grooves, procumbent and branched sometimes basally, yellow or brown strigose, lower internodes short. Leaves in whorls of 4–5, sessile; blade linear, 1.2–3.5 cm × 2–5.5 mm, obliquely spreading, papery, strigose, abaxially glandular, base broad cuneate, margin entire and strong revolute, apex acute, lateral veins inconspicuous. Spike terminal, simple, 1.5–10 cm × 7–8 mm, continuous and compact; flowers subsessile. Bracts and bracteoles linear to narrowly lanceolate, 1.5–3.3 mm long, equal to or longer than the corolla, gray strigose, gray-purple. Calyx campanulate, ca. 1.5 mm long, 5-veined, villous and sparsely glandular outside, glabrous inside; teeth 5, ovate-triangular, ca. 1/3 as long as calyx tube, hairy inside, margin ciliate. Corolla pink, purplish pink or red, ca. 2.3 mm, about 1.5 × as long as calyx, exserted, villous outside, subequally 4-lobed. Stamens 4, much exserted; filaments ca. 2.8 mm long, much exserted, inserted at the middle of corolla tube, bearded at middle, beard portion exserted; anthers 1-locular, cell apex dehiscent; style ca. 3.7 mm long; stigma bifid, lobes equal, ca. 0.6 mm long; disc ca. 0.3 mm long. Nutlets 4, oblong, ca. 0.6 mm long, dark brown, smooth, shiny.

Distribution and habitat:— The species is distributed in Cambodia, China, India, Laos, Nepal, Thailand, and Vietnam. In China, it occurs in Yunnan ( Figure 13 ). It grows in open ravines, grassy slopes, or near streams, at 1100–1800 m elevation.

Phenology:— Flowering and fruiting from July to December.

Taxonomic notes:— The species is similar to Pogostemon szemaoensis ( Wu & Hsuan 1965: 238) Press (1982: 74) in habit, but differs in its leaf margin being entire and strongly revolute (not remotely shallow serrate, flat or

28 • Phytotaxa 200 (1) © 2015 Magnolia Press

DENG & GE slightly revolute) and its stems covered with spreading and ascending strigose indumentum (not appressed strigose). This species is also similar to P. petelotii Doan ex Yao et al. (2013: 39) from Vietnam and Thailand, but differs in having the stems and leaves brown spreadingly hirsute (not whitish adpressed tomentose), hairs on leaves 2–3-cellular (not unicellular), leaf margins revolute and quite entire (not revolute and dentate upward), midrib inconspicuously elevated (not conspicuously elevated), lateral veins invisible (not distinct in 3–5 pairs), and the calyx tube rounded (not 4-angled).

Figures

FIGURE 13. Distribution maps of Pogostemon falcatus, P. cruciatus, P. fauriei and P. henanensis.