Pogostemon yatabeanus (Makino) Press (1982: 74)

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

27. Pogostemon yatabeanus (Makino) Press (1982: 74) . Dysophylla yatabeana Makino (1898: 55) . D. linearis var. yatabeana (Makino) Kudô (1929: 48) . Lectotype (designated by Panigrahi 1976: 479):— JAPAN. Honshu: Tokyo, Prov. Mushashi, Koiwa-Maru, 15 September 1883, Herb. Sc. College, Imp. Univ. Tokyo s.n. (K!, isolectotype TI).

Dysophylla martini Vaniot (1904: 178) . Type :— CHINA. Guizhou: “Kouy-tcheou, environs de Tsin-Tchen”, 13 September 1897, L. Martin & E. Bodinier 1946 (holotype E).

Dysophylla lythroides Diels (1926: 1031) . Pogostemon lythroides (Diels) Press (1982: 74) . Type: — CHINA. Zhejiang: Yeu chow, Suian hsien (Chunan Xian), 200 m, 15 October 1920, H.H. Hu 520 (holotype B probably destroyed).

Dysophylla tsiangii Y.Z. Sun in Sun & Hu (1966: 50), syn. nov. Pogostemon tsiangii (Y.Z. Sun) Press (1982: 74) . Type: — CHINA. Guizhou: Shuicheng, outside of E. Gate., in water, 23 October 1930, Y. Tsiang 9449 (holotype PE!, isotypes IBSC!, NAS!).

Annual herbs, 40–60 cm tall. Stems hollow, erect or procumbent at base, terete with shallow grooves, glabrous except for puberulent apex, usually unbranched or rarely short branched. Leaves in whorls of 3–4, sessile; blade linear, 3.5–7 cm × 5–7 mm, papery, glabrous, inconspicuously brown glandular abaxially, base acute, margin entire or obscurely remote serrate toward apex, apex obtuse, lateral veins inconspicuouse. Spike terminal, simple, 2.8–7 cm × ca. 1.5 cm, continuous and compact, sometimes interrupted basally; flowers subsessile. Bracts and bracteoles purplish, linear-lanceolate or filiform, 2–4 mm long, pilose. Calyx ovoid-campanulate, 1.6–2.1 mm long, 5-veined, pilose and glandular outside; teeth 5, triangular, subequal, 0.7–0.8 mm long, hairy inside, margin ciliate. Corolla purplish-red or purplish-blue, 3–3.5 mm long, c. 2 × as long as the calyx, glabrous, exserted, subequally 4-lobed, sparsely glandular outside. Stamens 4, much exserted; filaments 4–4.2 mm long, all inserted at a height of 1.5 mm in the tube, bearded at middle, bearded portion exserted; anthers 1-locular, cell apex dehiscent; style 5.5–5.8 mm long; stigma bifid, lobes subequally, 0.9–1.5 mm long. Nutlets 4, ellipsoidal, light brown, smooth.

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DENG & GE

Distribution and habitat:— The species is distributed in China, Japan, and Korea. In China, it occurs in Anhui, Guangxi, Guizhou, Hubei, Hunan, Jiangxi, Sichuan and Zhejiang ( Figure 19 ). It is found usually in rice paddies, near ponds or open wet places, at the elevation of 350–1200 m.

Phenology:— Flowering and fruiting from August to October.

Taxonomic notes:— Dysophylla lythroides ( Pogostemon lythroides ) was reduced to the synonymy of P. yatabeanus ( Dysophylla yatabeana ) by Wu & Huang (1977) and Li & Hedge (1994). But Bhatti & Ingrouille (1977) recognized it as an independent species and discussed that P. lythroides differs from P. yatabeanus by the number of leaves in whorls of 4 (not 3). However, leaves in whorls of 4 can also be observed in P. yatabeanus . Therefore, we treat P. lythroides as a synonym of P. yatabeanus again.

In the original description, it is indicated that Pogostemon tsiangii has leaves in whorls of 2 or 3. After examining type specimens, it was found that the leaves are indeed in whorls of 3 because those nodes with two leaves exhibit a scar which indicates that the third leaf has fallen off. Pogostemon tsiangii was reduced to synonymy of P. sampsonii ( Dysophylla sampsonii ) by Wu & Huang (1977). In fact, P. tsiangii is easily distinguished from P. sampsonii by the stem terete (not 4-angled), leaf margin with 1 or 2 obscurely teeth (not conspicuously serrate except for the basal 1/3 of leaf being entire), the calyx ca. 2.5 mm long (not ca. 1.5 mm long) and the corolla ca. 4.3 mm long (not ca. 2 mm long). These characters are however identical with P. yatabeanus .

Doubtful species

The following species was reported from China by some authors, but it can not be confirmed and is listed here as doubtful species because no specimens were available in the present study.

Pogostemon pressii Panigrahi (1984: 102) . Dysophylla griffithii Hooker (1885: 641) . Eusteralis griffithii (Hook. f.) Panigrahi (1976: 477) . Pogostemon griffithii (Hook.f.) Press (1982: 73) , nom. illeg. [non Prain]. Type:— INDIA. Tamil Nadu: Madras, no date, W. Griffith 3986 (holotype K!).

Note:— Bhatti & Ingouille (1997) noted that this species is distributed in China. However, no specimen of this species from China was discovered during the present study.

POGOSTEMON ( LAMIACEAE )

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Excluded species

The following species were placed in Pogostemon or Dysophylla previously but are now excluded from Pogostemon . Accepted names are in bold type.

Dysophylla communis Collett & Hemsley (1890: 114) = Elsholtzia communis (Coll. & Hemsl.) Diels (1912: 47) .

Dysophylla ianthina Maxim. ex Kanitz (1891: 46) . Pogostemon ianthinus (Maxim. ex Kanitz) Léveille (1911: 219) = Elsholtzia densa Bentham (1835: 714) .

Dysophylla mairei Léveillé (1912b: 236) = Elsholtzia pilosa ( Bentham 1830: 30) Bentham (1833: 163) .

Pogostemon cyprianii ( Pavolini 1908: 434) Pampanini (1910: 708) = Elsholtzia cyprianii (Pavol.) S. Chow ex Hsu (1965: 170) .

Pogostemon japonicus Bentham & Hooker (1876: 1180) = Comanthosphace japonica ( Miquel 1865: 103) Moore (1877: 293)

Figures

FIGURE 19. Distribution maps of Pogostemon szemaoensis, P. yatbeanus and P. quadrifolius.