Saussurea pseudoeriostemon Y. S. Chen, 2015

Chen, You-Sheng & Yuan, Qian, 2015, Twenty-six new species of Saussurea (Asteraceae, Cardueae) from the Qinghai-Tibetan Plateau and adjacent regions, Phytotaxa 213 (3), pp. 159-211 : 183-184

13. Saussurea pseudoeriostemon Y. S. Chen , sp. nov. ( Fig. 13 )

Type :— CHINA. Xizang: Nyalam County, 28°10 ʹ N, 85°57 ʹ E, alpine meadows and dwarf thickets, 3900–4000 m, 9 September 2012, FLPH Tibet Expedition 12-0372 (holotype PE; isotype PE) .

Saussurea taraxacifolia var. glabrescens Kitamura ex K. Fujikawa & H. Ohba in Ohba & Fujikawa (2000: 221), syn. nov.

Type:— NEPAL. Taplejung district: Topke Gola (3600 m)–Chodo Gyabo (4000 m), 20 August 1977, H. Kanai & Y. Tateishi 770934 (holotype TI).

Herbs perennial, 25–35 cm tall. Caudex branched at ground level, covered with fibrously lacerate remains of petioles. Stems numerous, simple, erect, 2–3 mm in diameter, sparsely arachnoid in the upper part, glabrescent in the lower part. Basal and lower stem leaves petiolate; petiole 3–12 cm long, glabrous; leaf blade oblong to elliptic, 7–18 cm long, 1.5–4(–6.8) cm wide, runcinate-pinnately lobed; lateral lobes 6–11 pairs, triangular to semiorbicular, 5–30 mm long, 4–18 mm wide, margin mucronate-dentate, apex acute and mucronate; leaf blade adaxially green, subglabrous, abaxially grayish green, sparsely arachnoid to glabrescent. Middle and upper stem leaves 3–6, gradually smaller, sessile, semiamplexicaul. Capitula solitary, terminal on stem. Involucre broadly campanulate, 1.8–3 cm in diameter. Phyllaries in ca. 5 rows, white arachnoid pubescent, apex acute and usually patent; outer phyllaries triangular-ovate, 9–10 mm long, 3–4 mm wide; inner phyllaries 13–15 mm long, 2.2–2.5 mm wide. Receptacle bristles subulate, 7–8 mm long. Corolla purple, 16–18 mm long, tube 8–9 mm long, limb 8–9 mm long, lobes ca. 5 mm long. Achenes cylindroid, ca. 4 mm long, ribbed, glabrous, apex with a short crown. Pappus light brown; outer bristles 3–4 mm long, scabrid; inner bristles 14–15 mm long, plumose.

Distribution and habitat: — Saussurea pseudoeriostemon occurs in southern Xizang, China and eastern Nepal. It grows in alpine dwarf thickets and meadows at altitudes of 3600–4150 m.

Phenology:—Flowering and fruiting from July to November.

Etymology:—The specific epithet reflects the similarity of the new species to S. eriostemon Wallich ex Clarke (1876: 229) . Chinese name: LJAEḂỆṈLẄ.

Additional specimens examined (paratypes):— CHINA. Xizang: Dinggyê County, Chentang Xiang, Meinuhu , 27°54 ʹ N, 87°35 ʹ E, forest margin, 4150 m, 15 July 2013, PE Tibet Expedition 3503 ( PE) ; Nyalam County, Quxiang, Deqingtang , in thickets, 3800 m, 30 August 1972, Xizang Chinese Medical Expedition 1643 ( PE) ; Nyalam County, grassy slopes, 3600 m, 14 June 1966, Y. T. Zhang & K. Y. Lang 4219 ( PE) ; Nyalam County, alpine meadows, 3630 m, 11 November 2011, Y. S. Chen et al. 752 ( PE) ; NEPAL. Taplejung district: Topke Gola (3600 m)— Chodo Gyabo (4000 m), 20 August 1977, H. Kanai & Y. Tateishi 766198 ( TI) .

Discussion:— Ohba & Fujikawa (2000) previously published a glabrescent variety of S. taraxacifolia (Lindley ex Royle 1835: 251) Wallich ex Candolle (1838: 532) based on specimens from eastern Nepal. After comparing its type materials with the above Tibetan specimens, we find they are the same species. These specimens are quite different from S. taraxacifolia , and should be treated as a distinct species. It is similar to S. taraxacifolia in its runcinate-pinnately lobed leaves, and capitula solitary and size, but differs by its caudex numerously branched (vs. usually simple), middle and upper leaves sessile and semiamplexicaul at base (vs. attenuate at base), leaves abaxially grayish green, sparsely arachnoid to glabrescent (vs. grayish white, densely tomentose), and phyllary apex acute and patent (vs. acuminate and appressed).

In our molecular tree, S. pseudoeriostemon is shown to be closely related to S. eriostemon . It is mostly close to S. eriostemon in habit, caudex usually branched, leaves runcinate-pinnately lobed and abaxially subglabrous, and capitula solitary and size, but differs by its caudex numerously branched (vs. simpe or few branched), middle and upper leaves base sessile and semiamplexicaul (vs. base attenuate), leaves abaxially grayish green, sparsely arachnoid to glabrescent (vs. pale green, subglabrous), phyllary apex acute and patent (vs. acute to acuminate, reflexed). A comparison of S. pseudoeriostemon with related species is given in Table 11.

Figures

FIGURE 13. Saussurea pseudoeriostemon. A. Habit. B. Anthers. C. Style branches. D. Outer pappus bristle. E. Inner pappus bristle. F. Floret (with pappus removed). G. Leaf lobe (abaxial and adaxial surfaces). H. Phyllaries (from left to right, outer to inner series). I. Floret. All from FLPH Tibet Expedition 12-0373 (PE). Drawn by Mr. Y.X. Zhu.