Saussurea yanyuanensis 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 : 198-200

21. Saussurea yanyuanensis Y. S. Chen , sp. nov. ( Fig. 21 )

Type:— CHINA. Sichuan: Yanyuan County, Wodi Xiang , Huolu Shan , alpine scree, 27°54 ʹ N, 101°37 ʹ E, 4170 m, 29 July 2011, Y. S. Chen & Y. C. Bi 11-075 (holotype PE; isotype PE) .

Herbs perennial, to 23 cm tall, caespitose. Caudex stout, dark brown, usually branched at ground level, covered with remains of petioles, often with several leaf rosettes and flowering shoots. Stems erect, simple, 4–6 mm in diameter, with dense white manicate hairs. Leaves grasslike, sessile, blade linear, adaxially light green, sparsely white pilose to glabrescent, abaxially with dense white manicate hairs, basally widened and sheathing stem, apex acute, margin revolute and entire or rarely fewly toothed at the base part, lower leaves 7–13 cm long, 3–9 mm wide, upper leaves smaller, 2–6 cm long, 3–5 mm wide. Capitula solitary, terminal on stem. Involucre subglobose, 2–2.5 cm in diameter, 1.8–2 cm high. Phyllaries in 5–6 rows, imbricate, dark brown, coriaceous; outermost ones densely white pilose, triangular-oblong, ca. 1.8 cm long, basal part broad, ca. 5 mm wide, apex acute; inner ones densely villous, ovate to oblong, 13–15 mm long, 3.8–6 mm wide, margin entire, apex acute; innermost ones densely pilose in the upper part, glabrous in the lower part, linear-oblong, ca. 14 mm long, ca. 2.5 mm wide. Receptacle densely bristly, bristles 7–9 mm long, persistent. Florets numerous, bisexual, fertile, corolla tubular-funnelform, dark purple, glabrous, tube ca. 7 mm long, limb ca. 5 mm long, throat ca. 1 mm in diameter, lobes ca. 4 mm long. Anthers blackish, ca. 5.4 mm long, apical appendage acute, basal appendages obtuse, auricles with lacerate tails ca. 1.5 mm long; style branches ca. 1.7 mm long. Achenes cylindroid, ca. 4.6 mm long, ca. 1.4 mm wide, glabrous, brown, with ca. 10 distinct ribs; apex with conspicuous denticulate crown; base truncate. Pappus grayish brown; outer bristles scabrid, 3–4 mm long; inner bristles 15–18, plumose, 11–17 mm long.

Distribution and habitat:— Saussurea yanyuanensis is currently known only from Yanyuan County, southwestern Sichuan. It grows in alpine scree slopes or grassy slope at altitudes of 3900–4200 m.

Phenology:—Flowering and fruiting from July to September.

Etymology:—The specific epithet is derived from its type locality, Yanyuan County. Chinese name: ÄDZṈLẄ.

Additional specimens examined (paratypes):— CHINA. Sichuan: Yanyuan County, Wodi, Huolu Shan, grassy slope, 3900–4200 m, 23 July 1983, Qinghai-Xizang Expedition 12299 (KUN, PE).

Discussion:—No species are shown to be closely related to S. yanyuanensis in our molecular tree. It is similar to S. loriformis Smith (1913: 114) and S. brunneopilosa Handel-Mazzetti (1937: 651) in its linear and grasslike leaves, caespitose habit and solitary capitula. However, it is different from these species by its broader leaves, phyllaries densely white pilose, phyllary apex acute and patent, achenes larger and pappus grayish brown. Comparing with S. yanyuanensis , S. loriformis is distinct by its leaf apex obtuse, phyllary apex long acuminate, apically usually reflexed, and pappus white; S. brunneopilosa is distinct by its stem slender and ca. 3 mm in diameter, leaf blade ca. 1 mm wide, phyllaries densely brown and white villous, phyllary apex long acuminate, apically usually reflexed, and pappus yellowish brown. A comparison of S. yanyuanensis and related species is given in Table 18.

Figures

FIGURE 21. Saussurea yanyuanensis. A. Habit. B. Style branches. C. Cross section of leaf. D. Phyllaries (from left to right, outer to inner series). E. Inner pappus bristle. F. Outer pappus bristle. G. Anthers. H. Floret (with pappus removed). I. Floret. J. Leaf section. All from Y. S. Chen & Y. C. Bi 11-075 (PE). Drawn by Mr.Y.X. Zhu.