Saussurea talungensis S.K.Ghimire & H.K.Rana, 2021

Rana, Hum Kala, Rana, Santosh Kumar, Sun, Hang, Fujikawa, Kazumi, Luo, Dong, Joshi, Laxmi Raj & Ghimire, Suresh Kumar, 2021, Saussurea talungensis (Asteraceae), a new species from Humla, Nepal Himalayas, PhytoKeys 176, pp. 55-66 : 55

publication ID	https://dx.doi.org/10.3897/phytokeys.176.61996
persistent identifier	https://treatment.plazi.org/id/66FB89B9-9C0E-2470-2065-8E288803964F
treatment provided by	PhytoKeys by Pensoft
scientific name	Saussurea talungensis S.K.Ghimire & H.K.Rana
status	sp. nov.

Treatment

Saussurea talungensis S.K.Ghimire & H.K.Rana sp. nov. Figs 1 View Figure 1 , 2 View Figure 2 , 3 View Figure 3

Type.

Talung valley , between Nyalu Pass and Ning Tsho, open gravelly or stony slopes, 30.234°N, 81.692°E, 4300 m a.s.l., 13 September 2012, S.K. Ghimire, A. Poudel, L.R. Joshi, S. Lo, P. Subedi, & C. Thapa CHH-1352 (holotype: KATH!; isotypes: TUCH!, KUN!) GoogleMaps .

Description.

Perennial herb, caespitose, 22-50 cm tall. Caudex branched, stout, apex covered with petioles’ residues. Stem well-developed leafy, erect, simple, stiff,> 1.3 cm in diameter, purplish-brown at maturity, covered with brownish-white tomentose hairs. Basal leaves petiolate; petioles 9.0-10.5 cm; leaf blades lanceolate, chartaceous, 10-15 × 2.5-4.0 cm, adaxially green, with brownish-white tomentose hairs, abaxially greenish-white, with dense white tomentose hairs, base attenuate, margin purplish, sinuate-dentate to shallowly pinnately lobed, lobe margins entire, apex acute to acuminate, midvein distinct, purplish-green. Cauline leaves 5-7, gradually decreasing in size upwards, margin purplish; lower cauline leaves petiolate, petiole to 4 cm, leaf blades lanceolate, 8.0-11.5 × 1.5-2.5 cm, apex acute or acuminate; middle and upper cauline leaves subsessile to sessile, narrowly lanceolate to linear, 4.0-7.5 × 0.6-1.2 cm, undivided, margin dentate, purplish-green uppermost leaves subtending the capitula or synflorescence. Capitula 1 or 3 (2 not seen), shortly pedunculate to subsessile, tomentose. Involucres campanulate, 1.2-2.0 cm in diameter. Phyllaries in 4 to 5 series, imbricate, densely tomentose, apically purplish, acuminate, spreading to reflexed; outer phyllaries ovate-elliptic, 7-10 × 3.0-3.5 mm, middle phyllaries elliptic, 11-13 × 2.5-3.0 mm, inner phyllaries narrowly elliptic to linear, 13-15 × ca. 2 mm, only tips densely tomentose. Receptacles with bristles, ca. 4 mm long. Florets> 20; corolla purplish, 10.0-12.5 mm long; limb 4-6 mm including 1.5-2.2 mm lobes; tube 5-7 mm long. Anthers ca. 5 mm long, tails lanate, ca. 1.2 mm long. Style branches ca. 1.2 mm long, reflexed, short, papillate. Achenes cylindrical, 3.5-4.5 × 1.5-2.0 mm, ribbed, glabrous, apex shortly crowned. Pappus in two rows, pale brown; outer bristles 3.0-4.5 mm, scabrid, deciduous; inner bristles 10-12 mm long, plumose, persistent, sub-equaling floret.

Phenology.

Flowering and fruiting from July to September.

Etymology.

The specific epithet is derived with reference to the type locality of Saussurea talungensis , Talung valley, Humla district, NW Nepal.

Distribution and habitat.

Saussurea talungensis is currently recorded only from the type locality in Talung valley (between Nyalu Pass and Ning Tsho), Humla district, NW Nepal (Fig. 1A-D View Figure 1 ). It grows on the alpine open gravelly or stony slopes at an elevation ca. 4300 m a.s.l. (Fig. 1C, D View Figure 1 ).

Conservation status.

Saussurea talungensis is restricted to a single mountain and is represented by ~50 mature individuals within an area of <500 m2 and appears to be local endemic. Moreover, its habitat and the population are subjected to high anthropogenic pressure, due to livestock grazing, and harvesting of caterpillar fungus and other aromatic plants used in medicine. Owing to population size, isolated distribution and observed constraints on the habitat due to anthropogenic pressure, Saussurea talungensis should be categorized as Critically Endangered [CR; B1ab (iii), B2ab (iii) and D] according to the IUCN Standards and Petitions Committee (2019).

Morphological affinities.

Critical examination of collected specimens, comparison with type material of allied taxa and relevant taxonomic literature revealed that S. talungensis is a new member of Saussurea (sect. Strictae) . Based on morphology, distribution and ecology, this population of Saussurea was initially considered as S. roylei from sect. Saussurea Strictae . To a certain extent it also resembles S. lanata in being a perennial herb with well-developed leafy stem, leaf blade undivided but lanceolate, many series phyllaries, campanulate involucres with more than 1 cm diameter, lanate anther tails, ribbed and glabrous achenes, and two rows of pale brown pappus. However, it differs from its allied taxa in having a number of qualitative and quantitative characters (see Table 2 View Table 2 ; Figs 2 View Figure 2 , 3 View Figure 3 ). Furthermore, in the western Himalayan alpine region, S. roylei is considered to have diverse morphological variations but this proposed new species owned peculiar affinities which undoubtedly differentiates it from the stated and other Saussurea species.

Molecular affinities.

The typical quadripartite structure of the newly sequenced plastome has size of 152,355 bp (37.7% GC content) consisting of a large single copy (LSC: 83,371 bp, 35.8% GC content), a small single copy (SSC: 18,562 bp, 31.4% GC content), inverted repeats (IRs: 25,211 bp, 43.1% GC contents each of IRA and IRB) (Fig. 1E View Figure 1 ). The newly sequenced chloroplast genome was used to determine the phylogenomic relationship of S. talungensis with its allied species and infer its position within Saussurea . The molecular phylogeny through BI and ML tree revealed that S. talungensis is nested within a clade comprising S. roylei , S. lanata , S. hookeri , S. eriostemon Wall. ex C.B.Clarke, S. leontodontoides (DC.) Sch.Bip., S. paleacea Y.L.Chen & S.Y.Liang, S. centiloba Hand.-Mazz., S. stella Maxim. and S. andryaloides (DC.) Sch.Bip. (PP> 0.98, BS> 93%; Fig. 4 View Figure 4 ). It is more evident that S. talungensis is a sister to S. roylei (an allied species), and is supported by Bayesian posterior probability (PP = 1) and Likelihood bootstrap support (BS = 98%) (Fig. 4 View Figure 4 ). Also, complete chloroplast genome structure is conservative in overall size and the order and size of each gene and intergenic region (Fig. 1E View Figure 1 ). The identical BI and ML phylogenomic tree using plastome sequence revealed that S. talungensis is most closely related to S. roylei (Fig. 4 View Figure 4 ), which is in congruence with the morphological observations.