Synotis nyalamensis M. Tang, C. Ren, Y.S. Chen & Q.E. Yang, 2022

Tang, Ming, Ren, Chen, Chen, You-Sheng & Yang, Qin-Er, 2022, Synotis nyalamensis (Asteraceae, Senecioneae), a new species from southern Xizang (Tibet), China, Phytotaxa 554 (3), pp. 278-284 : 280-283

Synotis nyalamensis M. Tang, C. Ren, Y.S. Chen & Q.E. Yang , sp. nov., Figs. 1 , 2A–C .

TYPE:— CHINA. Xizang, Nyalam county, Kangshan bridge to Zhangmu town , 28°02′29.52″N, 85°45′15.97″E, ca. 3200 m a.s.l., gravelly places on mountain slope, 26 August 2013 , M. Tang & C. Ren 485 (holotype IBSC, isotypes KUN, PE) . Fig. 1 .

Synotis kunthiana auct. non (Wallich ex Candolle 1838: 169) Jeffrey & Chen (1984: 288): Tang & Yang (2013).

Diagnosis:— Synotis nyalamensis is closely similar to S. kunthiana in having abaxially white-tomentose leaves and cylindric-campanulate capitula, but differs by having higher stature (45–60 vs. 20–40 cm), singular (vs. several) stems, caudate-acuminate (vs. acuminate) leaf tips, prominent (vs. obscure) nerves on abaxial side of leaves, more phyllaries (10–13, rarely 8 or 9 vs. 6–8), and more disk florets (15–24 vs. 7–12).

Description:—Perennial rhizomatous subshrubs. Rhizomes thick, woody. Stems solitary, erect, 45–60 cm tall, sparsely arachnoid-tomentose, proximally leafless at flowering time. Median stem leaves ovate-lanceolate, green, papery, 6–8 cm long, 3–5 cm broad, caudate-acuminate, remotely and minutely mucronulate-denticulate, adaxially sparsely pubescent, abaxially grey-whitish arachnoid-tomentose, pinnately veined, lateral veins 8–10; petiole 0.8–1.5 cm long; upper leaves becoming gradually smaller, sessile, oblong-linear. Capitula radiate, 3–8, loosely arranged in terminal and upper axillary corymbs on inflorescence branches; peduncles (1.0–)2.0– 4.5 cm long, slender, pubescent, bearing 1–3 filiform bracteoles. Involucres cylindric-campanulate, 8–10 mm long, 4–6 mm broad, with 8–10 subulate bracteoles at base, bracts of calyculus 5 to 8, filiform, green or purple, 6–8 mm long; phyllaries usually 10–13, rarely 8 or 9, linear-lanceolate, 1–2 mm broad, green, herbaceous, sparsely pubescent, margin narrowly scarious, apically acute, pubescent. Ray florets (6–)8, yellow; corolla tube 3–4 mm long; lamina oblong, 4–5 mm long, 1.5–2 mm broad, shallowly 2- or 3-denticulate, 3 or 4 veined, apex acute. Disk florets 15–24; corolla yellow, 7–10 mm long, with 3–4 mm long tube and infundibuliform limb; lobes ovate-triangular, 6–7 mm long, apically acute. Anthers 3–3.5 mm long; anther tails ca. 1.5 times the length of anther collars; appendages ovate-oblong; anther collars slightly dilated at base. Style arms ca. 1 mm long, fringed with short papillae, the apical tuft not differentiated. Achenes cylindric, 2–3 mm long, glabrous. Pappus white, 6–7 mm long.

Phenology:—Flowering from August to September; fruiting from October to December.

Etymology:—The specific epithet of our new species, “ nyalamensis ”, is derived from the type locality, i.e. Nyalam county in southern Xizang, China.

Distribution and habitat:— Synotis nyalamensis is currently known only from its type locality, i.e. Nyalam county in southern Xizang, China ( Fig. 5 ). It grows in gravelly places on mountain slope at an altitude of ca. 3200 m above sea level. Its putative closest ally, Syn. kunthiana , is distributed only in northwestern India, Nepal, and Pakistan, not in China ( Fig. 5 ).

Conservation status:— Synotis nyalamensis is a locally endemic species. During our field work we tried our best to search for it around the type locality but discovered only a small population with ca. 15 mature individuals. We have also been unable to trace any herbarium specimen of this species collected prior to us. According to IUCN Red List categories and criteria ( IUCN Standards and Petitions Subcommittee 2019), Syn. nyalamensis should be categorized as a Critically Endangered (CR) species.

Notes:—As pointed out by Jeffery & Chen (1984), a notable feature of the genus Synotis is the occurrence of closely similar, usually vicariant but sometimes partially sympatric sets of similar species, which on experimental study may prove better distinguished at subspecific rank. They gave eight examples in the Chinese flora. It seems that Syn. kunthiana and Syn. nyalamensis are an example in the Himalayan flora. Morphologically these two species, although different in some characters, are indeed closely similar to each other ( Table 1 ).

According to Jeffery & Chen (1984), Chen (1999) and Li et al. (2018), Synotis is divisible into two well-marked sections, sect. Synotis and sect. Karelinioidei (Fedtschenko & Fedtschenko ex Schischkin 1961: 751) Ren et al. in Li et al. (2018: 9). The former is divisible into five not very clearly differentiated series, with S. kunthiana belonging to Syn. ser. Fulvipapposae Jeffrey & Chen (1984: 332). Considering the remarkable morphological resemblance between Syn. nyalamensis and Syn. kunthiana , we propose to place Syn. nyalamensis also within this series.

Figures

FIGURE 1. Holotype sheet of Synotis nyalamensis sp. nov.

FIGURE 2. Synotis nyalamensis sp. nov. (A–C) and S. kunthiana (D–F), showing their rhizomes, proximal portion of stems, leaves and synflorescences.A. Rhizome and proximal portion of stem. B. Leaf (left: adaxial side; right: abaxial side. C. Synflorescence. D. Rhizome and proximal portion of stems. E. Median portion of stem, showing that the leaves are shortly petiolate. F. Synflorescence. A–C from M. Tang & C. Ren 485 (IBSC), D–F from Blinkworth, Wall. Num. List 3118/228 (K).

FIGURE 5. Distribution of Synotis kunthiana (■) and S. nyalamensis sp. nov. (●).