Tetrataenium mianguaqi Ze H. Wang & L. Chen, 2021

Wang, Ze-Huan, Wang, Yi, Liu, Bao-Lin, Wang, Chao-He & Fu, Xian-Guo, 2021, A new species of Tetrataenium (Tordyliinae, Apiaceae) from SW Yunnan, China, based on morphological and molecular data, Phytotaxa 491 (1), pp. 85-91 : 86-90

Tetrataenium mianguaqi Ze H. Wang & L. Chen , sp. nov. ( Figs. 2–3 )

Similar to Tetrataenium olgae Manden. , but differing mainly in the stems are slender and lower branched (vs. stout and middle upwards branched); the basal and lower leaves are peltate (vs. petiole base adnate).

Type: — CHINA. Yunnan: Cangyuan County, Yanshuai Town, Baling Village , 23°18′35.02″N, 99°31′25.18″E, elev. 1634.6 m, 26 Sep 2018, Liu Bao-lin & Wei Guang-rong et al. 5309270873 (holotype: KUN !, Isotype: CMMI) .

Herbs perennial, ca. 80–120 cm high. Root cylindrical, stout, divergent, yellowish white to tan. Stem slender, solitary, grooved, finely scabrous-hairy, hollow, branched upward from lower middle. Basal leaves with long stalks, petioles scabrous-hairy, base extended into sheaths. Leaf blade peltate, suborbicular, ca. 15cm in diameter, distinctly 5-lobed, apical lobes further ± shallowly 3-lobed, all lobes broadly ovate, apex round or acute, sparsely hirsute on both surface, especially along veins, margin irregularly serrate. Cauline leaves similar to the basal, reduced upward, smaller, from 5 shallow fission to 3 lobed, petiole peltate gradually to non-peltate. Umbels densely scabrous-hairy, 4.8–10.4cm wide; bracts absent; rays 10–16, 1.6–4.7cm, unequal; bracteoles 2–5, linear-lanceolate, unequal, 5–9mm, persistent; umbellule 7–25-flowered. Calyx teeth lanceolate. Petals white, obovate, apex acute, curved inward, abaxially glabrous, outer flowers in umbel conspicuously radiant. Stylopodium thick, style 1–1.2 mm long, ovary elliptic, scabrous-hairy. Young fruit oblong or elliptic, finely scabrous-hairy, back flattened, dorsal ribs filiform, lateral ribs broadly winged. Mature fruit not seen.

Distribution and Habitat: — Tetrataenium mianguaqi is currently encountered and seen growing in rocky habitats on cliff from four localities near Tuanjie Town (now merged into Yanshuai Town), Cangyuan County, Yunnan Province, China. The four localities are as follows: (1) Baling Village (23°18′35.20″N, 99°31′25.18″E), (2) Bannai Village (23°16′59.16″N, 99°28′10.82″E), (3) Nongke Village (23°19′56.36″N, 99°29′58.22″E), (4) Papai Village (23°18′08.17″N, 99°22′59.72″E) ( Fig. 4 ).

Phenology: —Flowering September – October; mature fruit not seen currently.

Etymology: —The epithet “mianguaqi” is the local name of the new species called by the local people in Cangyuan County. “miangua” refers to its leave shape similar to “nangua” ( Cucurbita moschata ), “qi” is a word usually used to indicate the anti-inflammation function of plants in minority area of Yunnan province.

Threat status: —To date, Tetrataenium mianguaqi has been found in four separate localities near the place of formerly Tuanjie Town (now merged into Yanshuai Town), Cangyuan County, Yunnan Province, China, where the largest one (Baling popution) with almost twenty individuals and the other three only a few individuals. Currently, the largest population may be destroyed by the road construction according to the report of the third author. Moreover, the new species has been traditionally used by the local people of Wa nationality in Cangyuan for several decades and still in use nowadays. Take all these factors into consideration, Tetrataenium mianguaqi seems to be an endangered species endemic to some small part of Tuanjie Town, Cangyuan County. However, a formal threat status assessment according to the IUCN criteria and categories ( IUCN 2001) for this species requires more data on its actual and historical distribution and population sizes in relation to land use changes. Thus, its status should be of concern and addressed by further investigations.

Notes: —According to the latest comprehensive phylogenetic study of Chinese Heracleum based on 114 nrDNA ITS sequences, Tetrataenium should be treated as a separate genus with 5 species distributed in China: T. olgae , T. nepalense , H. bivittatum , H. kingdonii , H. yunnanense ( Yu et al. 2011) . All these species have bipinnatifid leaves and mainly distributed in Yunnan and Xizang except T. olgae , which have pinnatilobate leaves and distributed in Xinjiang. In our molecular phylogenetic study, the new species T. mianguaqi is shown to be nested between T. olgae and all the other four species, with a closer relationship to the latter four ( Fig. 1 ), which is consistent with its distributional area. The morphological comparison of the six Tetrataenium species is shown in table 1.

The new species is a good medicinal resources of anti-inflammation function, which has been traditionally used by the local people of Wa nationality in Cangyuan for several decades and still in use nowadays. Given its limited population, special habitat and good medicinal values, more attention should pay to its population dynamics for continuous use.

Figures

FIGURE 1. Jackknife 50% majority-rule tree of tribe Tordylieae (Apiaceae) and outgroups based on the nrITS region. The MP jackknife support (JK) values are shown above the branches and the BI posterior probabilities (PP) are given below the branches.

FIGURE 2. Tetrataenium mianguaqi. A. plants; B. inflorescences with petals; C. inflorescences without petals; D. infructescence with young fruits; E. flower with petals; F. young fruit. Drew by Dr. Yuan Luo.

FIGURE 3. Tetrataenium mianguaqi. A. plants; B. root; C. basal leaf; D. inflorescences; E. young fruit. Photographed by Li Chen.

FIGURE 4. Distribution map of the four populations of Tetrataenium mianguaqi.