Saussurea xianrendongensis 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 : 188

15. Saussurea xianrendongensis Y. S. Chen , sp. nov. ( Fig. 15 )

Type:— CHINA. Yunnan: Shangri-la County, Xianrendong , 27°46 ʹ N, 99°39 ʹ E, rocky slopes in a small valley, 3400 m, 23 August 2010, Kham Expedition 10-2675 (holotype PE; isotypes PE) .

Herbs perennial, 20–40 cm tall. Caudex branched, fibrously split. Stems usually several, erect, simple, base covered with fibrous petiole remains. Basal and lower stem leaves petiolate; petiole 2–5 cm long; leaf blade linear, 12–20 cm long, 0.6–1 cm wide, margin with 1–3 pairs of runcinate distinct teeth; teeth linear or obliquely narrowly triangular, reclinate; blade adaxially green, glabrous, apex acute to acuminate, abaxially grayish white arachnoid tomentose; terminal lobe linear. Middle and upper stem leaves gradually smaller upward on stem, 2.5–14 cm long, 1.5–2.5 mm wide, margin entire, apex acuminate. Capitula solitary, terminal on stem. Involucre campanulate, 1.5–2 cm in diameter. Phyllaries in ca. 5 rows, linear, subequal, apex green and acute; outer phyllaries 16–18 mm long, ca. 2 mm wide, white pubescent, apex patent; middle phyllaries 16–18 mm long, ca. 2 mm wide, white pubescent, apex patent; inner phyllaries 16–17 mm long, 1–2 mm wide, apex appressed. Receptacle bristles 6–8 mm long. Corolla purple, ca. 12 mm long, tube 6–7 mm long, limb 5–6 mm long, lobes ca. 3 mm long. Achenes cylindroid, ca. 3.4 mm long, ribbed, glabrous. Pappus light brown; outer bristles ca. 3 mm long, scabrid; inner bristles ca. 11 mm long, plumose.

Distribution and habitat:— Saussurea xianrendongensis is currently only known from its type locality. It grows in rocky slopes in a small valley at an altitude of 3400 m.

Phenology:—Flowering and fruiting from August to September.

Etymology:—The specific epithet is derived from its type locality, Xianrendong. Chinese name: IJλÑṈLẄ.

Discussion:— Saussurea xianrendongensis belongs to S. subgen. Saussurea sect. Strictae because of its pinnately lobed leaves and solitary capitula. It is similar to S. yunnanensis var. runcinata Franchet (1888: 340) in the habit, linear leaves, leaves abaxially grayish white arachnoid tomentose, capitula size, subequal phyllaries, phyllaries apex acuminate, but differs by its leaf blade always linear (vs. elliptic, narrowly elliptic, or linear), phyllaries apex acute and patent (vs. caudate acuminate and appressed).

In our molecular tree, S. xianrendongensis is shown to be weakly related to S. pseudolingulata . It is similar to S. pseudolingulata in its runcinate pinnately lobed or toothed leaves, leaves abaxially grayish white arachnoid tomentose, capitula solitary, and phyllaries green, but differs by its leaf blade linear, less than 1 cm wide, teeth 1–3 pairs (vs. narrowly elliptic, 1–2 cm wide, lobes 6–13 pairs), and phyllaries green, apex acute and patent (vs. blackish purple, apex acuminate and appressed). A comparison of S. xianrendongensis with related taxa is given is Table 12.

Figures

FIGURE 15. Saussurea xianrendongensis. A. Habit. B. Style branches. C. Floret (with pappus removed). D. Anthers. E. Inner pappus bristle. F. Outer pappus bristle. G. Phyllaries (from left to right, outer to inner series). H. Leaf lobe. I. Floret. All from Kham Expedition 10-2675 (PE). Drawn by Mr. Y.X. Zhu.