Thalictrum bouffordii Y. P. Zeng, Q. Yuan & Q. E. Yang, 2021

Zeng, You-Pai, Yuan, Qiong & Yang, Qin-Er, 2021, Thalictrum bouffordii (Ranunculaceae), a new species from the Qionglai mountains region in western Sichuan, China, Phytotaxa 510 (1), pp. 18-28 : 18-26

publication ID

https://doi.org/ 10.11646/phytotaxa.510.1.2

DOI

https://doi.org/10.5281/zenodo.5485214

persistent identifier

https://treatment.plazi.org/id/024EB22E-FFCA-C336-F992-5C617A1EF7B3

treatment provided by

Marcus

scientific name

Thalictrum bouffordii Y. P. Zeng, Q. Yuan & Q. E. Yang
status

sp. nov.

Thalictrum bouffordii Y. P. Zeng, Q. Yuan & Q. E. Yang View in CoL , sp. nov. ( Figs. 1‒4 View FIGURE 1 View FIGURE 2 View FIGURE 3 View FIGURE 4 ).

Type:— CHINA. Sichuan: Tianquan county, Xingou town , along G318 highway, near Chizhuping , 29°53′16.75″N, 102°21′21.77″E, on moist cliffs in ravine, 1690 m, 6 July 2020, Y. P. Zeng & Q. L. Huang 352 (holotype IBSC, barcode unavailable; isotypes CDBI, IBSC, PE, barcodes unavailable) GoogleMaps .

Description:—Perennial herbs. Roots fibrous. Stem to 100 cm tall, striate, distally branched. Leaves 2‒4-ternate; blade triangular, 10‒25 cm long and broad; leaflets ovate, broadly ovate or rhombic, 1‒3 cm long, 0.8‒2.5 cm broad, papery, both sides glabrous, green on adaxial side, pale green on abaxial side, base rounded or subcordate, apex obtuse or acute, 3-lobate; lobes entire or 2‒3-lobate, apex obtuse or acute; veins flat adaxially, slightly raised abaxially; petiole slender, 1.5‒10 cm long; stipule membranous, margin torn. Inflorescence a many-flowered corymbiform compound monochasium, dichotomous; rachis glabrous or sparsely pubescent. Pedicels 0.8‒1.5 cm long, glabrous or sparsely pubescent. Flowers bisexual, erect. Sepals 4‒5, caducous, cymbiform-elliptic, ca. 4 mm long, ca. 2 mm broad, whitish tinged with purplish to distinctly purple, abaxially pubescent. Stamens ca. 60, 6‒ 7 mm long; filaments clavate, ca. 5.5 mm long, purplish; anthers oblong, ca. 1.5 mm long, apex obtuse, white. Carpels 6‒10, sessile, ca. 2 mm long; ovary lunate-fusiform, shallowly ribbed, ca. 1 mm long, glabrous or sparsely pubescent; style ca. 1 mm long, recurved at apex; stigma conspicuous, linear, ca. 0.5 mm long. Immature achenes sessile, ca. 3 mm long; body fusiform, profoundly ribbed, pubescent; style persistent, recurved at apex.

Distribution and habitat:— Thalictrum bouffordii is currently known from Luding, Shimian and Tianquan counties in the Qionglai mountains region in western Sichuan, China ( Fig. 5 View FIGURE 5 ). It grows along forest margins or on moist cliffs in ravines at altitudes of 1360‒3200 m above sea level.

Phenology:—Flowering from June to October; fruiting from July to November.

Etymology:—It is a great privilege to name our new species in honor of Dr. David E. Boufford with Harvard University Herbaria, one of the greatest hunters of Chinese plants. His specimens of Chinese plants are among the finest ever made, a real joy to study. As a member of the editorial board of the Flora of China completed in 2011, Dr. Boufford is also a very active researcher of Chinese plants and a most helpful friend of many Chinese plant taxonomists, including the third author of this paper.

Additional specimens examined:— CHINA. Sichuan: Luding, K.Y. Lang, L.Q. Li & Y. Fei 1351 (KUN0689899, PE01108835, PE01108836), G.H. Xu 26353 (CDBI0026148, CDBI0026149); Shimian, C.C. Hsieh 41833 (IBSC0090544, PE00471029, PE00471091, SZ00092282, SZ00092301, WUK, barcode unavailable), Shimian Exped. 78-1050 (SM704604597, SM704604743); Tianquan, D.F. Chamberlain & F.T. Pu 148 (CDBI0026494), X.J. He & Q.S. Zhao 171869 (SZ00571393, SZ00571413, SZ00571414, SZ00571415), X.J. He & Q.S. Zhao 190519 (SZ00578647, SZ00578648), X.J. He & Q.S. Zhao 192292 (SZ00571336, SZ00571337, SZ00571338), K.C. Kuan & W.T. Wang 3247 (K, barcode unavailable, PE00471028, PE00471030), N. Liu ELS008 (BNU0020049), C. Pei 8268 (NAS00187295, NAS00187297, SZ00092590), D.Y. Peng 46583 (CDBI0026159, IBSC0090429), Sichuan Econ. Plant Exped. 540 (PE00471031, PE00471033), P.C. Tai & C.M. Teng 4378 (SZ00092589), H.L. Tsiang 34799 (IBK00012648, IBSC0090351, PE00471035, SZ00092274), H.L. Tsiang 35238 (NAS00187277, PE00470992, SZ00092272), Y.P. Zeng & Q.L. Huang 355 (IBSC, barcode unavailable).

Conservation status:— Thalictrum bouffordii is currently known from Luding, Shimian, and Tianquan counties in the Qionglai mountains region in western Sichuan, China. The two populations in Luding and Tianquan, which we visited in 2020, consist of at least 100 individuals each. However, the size of the population in Shimian remains unknown. The conservation status of T. bouffordii should be considered as “Data Deficient (DD)” before adequate information of this species is acquired ( IUCN Standards and Petitions Committee 2019).

Notes:— Thalictrum bouffordii is most closely similar to T. xinningense Wang (2017: 408) ( Figs. 6‒8 View FIGURE 6 View FIGURE 7 View FIGURE 8 ) in habit and having clavate filaments, apically recurved styles, and sessile, profoundly ribbed and pubescent achenes, but differs by having proximally glabrous (vs. densely pubescent) stem ( Figs. 3D View FIGURE 3 , 7D View FIGURE 7 ), inflorescence a many-flowered corymbiform compound monochasium (vs. a thyrse) ( Figs. 1 View FIGURE 1 , 2 View FIGURE 2 , 3B View FIGURE 3 , 4B View FIGURE 4 , 6 View FIGURE 6 , 7B View FIGURE 7 , 8 View FIGURE 8 ), abaxially pubescent (vs. glabrous) sepals ( Figs. 3I View FIGURE 3 , 4G View FIGURE 4 , 7I View FIGURE 7 ), and purplish (vs. white) filaments ( Figs. 3J View FIGURE 3 , 4H View FIGURE 4 , 7J View FIGURE 7 ) (also see Wang 2017, 2018a). Geographically T. bouffordii occurs in western Sichuan, whereas T. xinningense is widely distributed in southern Chongqing, northern Fujian, northern Guangdong, northern Guangxi, eastern Guizhou, southwestern Hubei, Hunan, northern Jiangxi, and southern Zhejiang ( Zeng et al. 2020a); both species are thus geographically isolated from each other ( Fig. 5 View FIGURE 5 ).

As mentioned above, specimens of Thalictrum bouffordii had all been previously misidentified as T. javanicum . Indeed, T. bouffordii is somewhat similar to T. javanicum in habit, but differs by having abaxially pubescent (vs. glabrous) sepals, purplish (vs. white) filaments, and pubescent (vs. glabrous) achenes (also see Backer & Bakhuizen van den Brink 1963). Moreover, as noted by Zeng et al. (2020b), previous records of the occurrence of T. javanicum in China might be a mistake caused by the misapplication of this name to the relevant Chinese populations. The descriptions of T. javanicum in the Chinese floristic works by various authors, including Anonymous (1972, 1976, 2014), Wang & Wang (1979), Wang (1985, 1991, 1993, 2000, 2003, 2004, 2018a), Lin & Zhao (1985), Li (1986), Lin (1992), Liu (2000), Fu & Zhu (2001), Luo & Luo (2008), Wang & Liu (2016), and Xie et al. (2016), have been made mainly based on Chinese specimens, not on material from the type locality, i.e. Java in Indonesia. These Chinese specimens actually belong to T. nepalense Wang (2018b: 641), T. xinningense , and our new species as well, respectively. An identification key to T. bouffordii and its closely similar species including T. javanicum , T. nepalense and T. xinningense is given below.

Y

Yale University

P

Museum National d' Histoire Naturelle, Paris (MNHN) - Vascular Plants

Q

Universidad Central

L

Nationaal Herbarium Nederland, Leiden University branch

IBSC

South China Botanical Garden

CDBI

Chengdu Institute of Biology

PE

Institute of Botany, Chinese Academy of Sciences

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