Hanceola yuanyangensis Y. S. Chen, C. L. Xiang & H. L. Zheng, 2021

Chen, You-Sheng, Xiang, Chun-Lei, Wu, Jian-Yong, Liao, Jun-Jie & Zheng, Hai-Lei, 2021, Hanceola yuanyangensis (Lamiaceae, Nepetoideae), a new species from Yunnan, China, Phytotaxa 480 (3), pp. 297-300 : 297-299

Hanceola yuanyangensis Y. S. Chen, C. L. Xiang & H. L. Zheng , sp. nov. ( Figs. 1–2 )

Type:— CHINA. Yunnan Province, Yuanyang County, Majie, Dengyun , Zengyizhai , in the evergreen mixed forests, 2250 m, 28 Oct. 2019, Y. S. Chen et al. YY0522 (holotype IBSC ; isotypes IBSC, KUN) .

Diagnosis:— Hanceola yuanyangensis is morphologically most similar to H. tuberifera Sun (1942: 123) but differs by its tuber ca. 3 cm in diameter, corolla 2.6–3 cm long and 10 mm in diameter, style distinctly exserted and distinctly bilobed.

Perennial herbs, 30–50 cm tall. Rhizomes with woody, moniliform tubers ca. 3 cm in diam. Stems erect, branched or unbranched, subterete, glandular puberulent, young stems and branchlets obtusely 4-angled, Leaves opposite; lamina oblong, ovate to ovate-lanceolate, papery, 6–12 cm long, 2.2–4.6 cm wide, apex acute to acuminate, base cuneate, margin serrate, adaxially green, glabrous, abaxially light green or purple, sparsely glandular, puberulent on veins, otherwise glabrous; lateral veins 4–5 paired; petioles 0.5–2.5 cm long, glabrous. Inflorescence terminal, 10–28 cm long, cymes 1–3-flowered; peduncles 2–3 mm long, pedicels 4–5 mm long, densely purplish glandular puberulent; bracts lanceolate to linear, 3–4 mm long, bracteoles linear, 1–2 mm long, densely whitish puberulent. Calyx campanulate, ca. 3 mm long, 10-veined, densely whitish glandular puberulent and glandular outside; 2-lipped to 1/2 its length, posterior lip 3-toothed, teeth broadly triangular, apex acuminate, median lobe larger, anterior lip 2-toothed, teeth triangular, apex acuminate. Corolla purple, narrowly funnelform, tube dilated upward, 2.6–3 cm long, glandular puberulent outside, tube dilating at midpoint, ca. 1–2 mm in diameter at base, gradually dilated to 1 cm at apex, glabrous inside; limb 2-lipped, posterior lip 2-lobed, lobes slightly reflexed, orbicular, ca. 2 mm long, anterior lip 3-lobed, lobes oblong, ca. 4 mm long. Stamens 4, free filaments inserted at apical ca. 1/4 the length of anterior corolla, unequal in length for each of them; anterior pair longer, slightly exserted, posterior pair included; anthers ovoid, cells 2, divaricate, confluent at apex; filaments glabrous. Style distinctly exserted, ca. 3.6 cm long, apex distinctly bilobed; disc 4-lobed, lobes alternating with mericarps, anterior lobe much larger.

Phenology:—Flowering from October to November.

Etymology:—The epithet of the new species refers to its type locality, Yuanyang county. Chinese name: 元ḄƱƗḗ (Yuan Yang Si Lun Xiang).

Distribution and habitat:— Hanceola yuanyangensis is currently only known at the one locality from Yuanyang county in Yunnan province of China. It grows in the evergreen mixed forests at an elevation of 2250 m.

Conservation status: — Hanceola yuanyangensis is presently known only from its type locality with no more than 20 individuals. Although we have carried out a lot of field investigation in Yuanyang county, no other population has been found at present. This species maybe easily threaten by habitat lose. Since it is small size of population, this new species should be considered Critically Endangered (CR: B1, 2a; C2a) based on the IUCN Red List Categories and Criteria ( IUCN 2019).

Additional specimens examined:— CHINA. Yunnan Province, Yuanyang County, Majie, Dengyun , Zengyizhai , 2250 m, 6 Apr. 2019, Y. S. Chen et al. YY1048 (IBSC) .

Discussion:— Hanceola yuanyangensis is most similar to H. tuberifera in its rhizomes with woody, moniliform tubers, leaf blade elliptic, inflorescence glandular puberulent, but differs by its tuber ca. 3 cm in diameter, corolla 2.6–3 cm long and 10 mm in diameter, style distinctly exserted and distinctly bilobed, and flowering from October to November. Whereas in H. tuberifera , tuber ca. 6 mm in diameter, corolla 2.1–2.6 cm long and 5–6 mm in diameter, style included and slightly 2-cleft, and flowering from July to August.

Hanceola yuanyangensis is also similar to H. exserta Sun (1942: 125) in its habit, leaf shape, corolla color, style distinctly exserted, but differs by its rhizomes with woody, moniliform tubers (vs. without tubers), stamens included and straight (vs. stamens distinctly exserted and curved), limb without spots inside (vs. dotted with purple spots inside), style distinctly bilobed (vs. slightly 2-cleft).

Figures

FIGURE 1. Line illustration of Hanceola yuanyangensis sp. nov. A. flowering branch; B. dissected corolla; C. dissected calyx; D. rhizome with tuber; E. pistil. All drawn by Bing-Mou Wang from Y. S. Chen et al. YY0522.

FIGURE 2. Hanceola yuanyangensis sp. nov. in the wild. A. habit; B. living plants with tubers; C. corolla in lateral view; D. opened corolla showing style and stamens. (A & C taken by Jun-Jie LIAO from Y. S. Chen et al., YY0522; B taken by You-Sheng CHEN from Y. S. Chen et al. YY1048); D taken by Hai-Lei ZHENG from Y. S. Chen et al. YY0522.