Pogostemon henanensis Gang Yao, 2015

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

21. Pogostemon henanensis Gang Yao , sp. nov. Figure 14 .

Diagnosis: This species is similar to Pogostemon stellatus in habit, but differs in its leaves in whorls of 3, calyx c. 1.6 mm long and corolla c. 2.5 mm long.

Type:— CHINA. Henan: Songxian, Longchiman Nature Reserve , 600 m, 17 August 1983, Expedition for Plant Resource 20263 (holotype PE!) .

Annual herbs, to 30 cm long. Stems with shallow grooves, glabrous, short branches usually axillary. Leaves in whorls of 3, sessile; blade linear, 1.5–6 cm × 4–7 mm, adaxially glabrous, abaxially glabrous and densely yellow brown glandular, base attenuate, margin remote serrate upward, apex acuminate, midvein slightly elevated abaxially, lateral vein inconspicuouse. Spike terminal, simple, ca. 7.5 cm × 8 mm, continuous and compact; flowers sessile. Bracts and bracteoles linear, 2–2.5 mm long, villous. Calyx funnelform, ca. 1.6 × 1.5 mm, 5-veined, densely hairy and glandular outside, glabrous inside; teeth 5, triangular, ca. 0.6 mm long, ca. 0.6 mm wide at base, margin ciliate. Corolla purplish red, ca. 2.5 mm long, exserted, sparsely glandular outside, glabrous inside, subequally 4-lobed, center lobe ca. 2 mm long. Stamens 4, erect, much exserted; filaments ca. 3.4 mm long, all inserted at a height of 1 mm in the tube, bearded at middle, bearded portion exserted; anthers 1-locular, cell apex dehiscent; style ca. 5.4 mm long; stigma bifid, lobes equal ca. 0.8 mm. Disc ca. 0.3 mm long. Nutlet unknown.

Distribution and habitat:— The species is only known from its type locality, Longchiman Nature Reserve, Songxian, Hennan, China ( Figure 13 ). It grows near water at an elevation of about 600 m.

Phenology:— Flowering in August.

Etymology:— Pogostemon henanensis is named after its type locality, Henan province.

Taxonomic notes:— This new species is similar to Pogostemon stellatus in habit, but differs in its leaves in

POGOSTEMON ( LAMIACEAE )

Phytotaxa 200 (1) © 2015 Magnolia Press • 29 whorls of 3 (not 4–8), calyx ca. 1.6 mm long (not 1.2 mm), corolla ca. 2.5 mm long (not 1.5–1.8 mm). It also resembles to P. faurei , but differs from in having leaves 1.5–6 cm long (not 1.2–3.5 cm long), leaf margins conspicuously serrate (not obscurely dentate or entire), and spikes 7.5 cm long (not to 2.5 cm long).

Figures

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

FIGURE 14. A–G. Pogostemon henanensis. A. Habit; B. Calyx split; C. Corolla; D. Corolla split open with stamens; E. Style; F. Stamen; G. Bract and bracteole. Drawn by Y. X. Liu based on Expedition for Plant Resource 20263 (PE).