Pogostemon septentrionalis Wu & Huang (1977: 369)

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

10. Pogostemon septentrionalis Wu & Huang (1977: 369) . Type: — CHINA. Guangdong: Wengyuan , 14 October 1935, S.K. Lau 24884 (holotype IBSC!). Figure 8 .

Perennial herbs or subshrubs, 1.5–2 m tall. Stems erect, terete or obscurely angular, finely strigillose, slightly dilated at nodes. Leaves opposite; petiole 0.5–5.5 cm long, glabrous or sparsely strigillose; blade ovate to rhombicovate, 4–12 × 2–8 cm, herbaceous, adaxially glabrous or sparsely strigillose, abxially glabrous or strigillose along veins, base broadly cuneate to cuneate-attenuate, margin double serrate, apex acuminate, lateral veins 3 or 4 pairs on each side of the midvein, conspicuously elevated abaxially. Spikes 3–13 cm long, 7–9 mm wide, terminal and axillary, continuous, with more than two lateral branches; peduncle 0.5–3.5 cm long; verticillasters many-flowered, flowers sessile. Bracts and bracteoles lanceolate, oblong-lanceolate, or ovate-lanceolate, 3–4 mm long, subequal or slightly shorter than calyx in length, pubescent, margin ciliate. Calyx infundibuliform, 3–4 mm long, 5-veined, subglabrous or pubescent and glandular outside, glandular inside in flower but glabrescent in fruit; teeth 5, triangular, equal, 1/3–1/2 as long as the calyx tube, sparsely pubescent or glabrous inside, margin ciliate. Corolla white to purple, 4–4.5 mm long, slightly exserted from calyx, 2-lipped, upper 3-lobed, lobes apex obtuse, lower lip entire, apex acute. Stamens 4, erect, exserted; filaments ca. 3.5 mm long, inserted at middle of corolla tube, beared at middle; anther 1-locular, cell apex dehiscent. Style 4–4.5 mm long; stigma bifid, equal, 0.7–0.8 mm long; disc ca. 0.5 mm long. Nutlets 4, 0.9–1 mm long, black or dark brown, orbicular or obovoid.

Distribution and habitat:— This species is endemic to China and occurs in Fujian, Guangdong, Guangxi, and Hunan ( Figure 7 ). It grows in ravines, near streams, or on slopes, at 100–800 m elevation. Phenology:— Flowering from September to October and fruiting from November to December.

Taxonomic notes:— Pogostemon septentrionalis resembles P. chinensis , and the distinguishing characters are discussed under P. chinensis .

18 • Phytotaxa 200 (1) © 2015 Magnolia Press

DENG & GE

Figures

FIGURE 7. Distribution maps of Pogostemon parviflorus, P. septentrionalis, P. xanthiiphyllus and P. brachystachys.

FIGURE 8. A–H. Pogostemon septentrionalis. A. Habit; B. Flower; C. Calyx; D. Corolla split open with stamens; E. Style; F. Stamen; G. Nutlets; H. Bracts. Drawn by Y.X. Liu based on S. K. Lau 24884 (IBSC).