Saussurea bhutanensis Y. S. Chen, 2014

Chen, You-Sheng, 2014, Six new species of Saussurea (Asteraceae) from eastern Himalaya, Phytotaxa 177 (4), pp. 191-206 : 199

5. Saussurea bhutanensis Y. S. Chen , sp. nov. ( Fig. 5 , 9A & 9B )

Type:— CHINA. Xizang: Yadong, Pagri , mountains between border of China and Bhutan , 27°37’ N, 89°07’ E, sandy meadows, 4870 m, 25 August 2013, FLPH Tibet Exped.13-2131 (holotype PE; isotypes PE) .

Herbs 1–4 cm tall, perennial, stemless, caespitose. Caudex 2–3 cm in diam., usually much branched. Rosette leaves sessile, linear, 10–25 × 1–1.5 mm, abaxially greyish white and densely tomentose-sericeous, adaxially green, shiny, and glabrous, base enlarged, sheathing, and white villous, margin entire and revolute, apex acute. Uppermost leaves merging into phyllaries, supporting capitula. Capitula solitary, in center of leaf rosette or terminal on stem, sessile, concealed by villous hairs. Involucre campanulate, 1–1.6 cm in diam. Phyllaries in ca. 6 rows, apex acuminate to caudate; outer phyllaries narrowly ovate-triangular, 14–16 × 3–4 mm, basal part dark green, apical part greenish, sparsely villous, and reflexed; middle and inner phyllaries narrowly ovate-triangular to narrowly elliptic-linear, 11–13 × ca. 2 mm, basal part pale yellow, apical part blackish purple, villous, and reflexed. Receptacle bristles very few, 1–2 mm long. Corolla purplish, 1.3–1.5 cm long, tube 7–8 mm long, limb 6.5–8 mm long, lobes 3.5–4 mm long. Achene dark brown, conic, ca. 3 mm long, glabrous. Pappus in 2 rows; outer bristles white, 2–3 mm long, scabrid; inner bristles pale brown, 9–10 mm long, plumose.

Distribution and habitat: — Saussurea bhutanensis occurs in northern Bhutan and adjacent border of Yadong, Xizang, China. It grows on alpine sandy meadows (including Saussurea , Aster , Primula , Arenaria , Gentiana , Swertia , Cyananthus , Saxifraga and Delphinium species ), alpine scree or limestones at altitudes of 4500–4900 m.

Phenology:—Flowering and fruiting from August to October.

Etymology: —The specific epithet is derived from its main distribution area, Bhutan.

Additional specimens examined (paratypes): — BHUTAN. [Bumthang district]: Tolegang, Tsampa, steep open hillside, 4720 m, 2 October 1949, F . Ludlow, G . Sherriff & J. H . Hicks 19784 ( BM, E); [Wangdi district]: Wangdue-Phodrang , Thampe La , limestone, 27°43’ N, 90°18’ E, 4500–4600 m, 28 September 2000, G. & S . Miehe 00-421-01 ( E) .

Discussion:— Saussurea bhutanensis belongs to S. subgen. Saussurea sect. Lagurostemon on account of its leaf blade being linear, entire, grasslike, and the capitula solitary, 1–1.6 cm in diameter.

Grierson & Springate (2001) reported one specimen from Bhutan (F. Ludlow, G. Sherriff & J. H. Hicks 19784) that is related to Saussurea columnaris Handel-Mazzetti (1937: 652) , but they noted this specimen is different from the typical S. columnaris in its receptacle naked, achene glandular-stipitate above and habit usually stemless. This kind of specimen was also found from the Tibetean border with Bhutan (FLPH Tibet Exped.13-2131) by the present author in 2013. But the present author found its receptacle is not entirely naked but with few short bristles 1–2 mm long, achenes glabrous, leaves 1–2.5 cm long, phyllaries usually narrower and apex acuminate, capitula concealed by dense villous hairs. Typical specimens of S. columnaris from Yunnan are different in the receptacle bristles ca. 7 mm long and plants usually stemmed, leaves 2–7 cm long, phyllaries usually broader and apex acute, capitula not concealed by villous hairs. Saussurea bhutanensis is also similar to S. durgae Jeffrey & Srivastava (1997: 235) in its caespitose habit and linear grassy leaves, but S. bhutanensis differs in its leaves adaxially green, shiny, and glabrous, capitula concealed by villous hairs, and corolla purplish, whereas S. durgae differs in its leaves densely clothed with greyish white wooly hairs on both surfaces, capitula not concealed by villous hairs, and corolla pink. A comparison of S. bhutanensis , S. columnaris and S. durgae is given in Table 5.

Figures

FIGURE 5. Saussurea bhutanensis. A. Habit. B. Cross section of leaf. C. Phyllaries and supporting leaves (from left to right, outer to inner series, one to three are supporting leaves, four to nine are phyllaries). D. Anther. E. Florets. F. Outer pappus. G. Floret, with pappus removed. H. Inner pappus. I. Style branches. All from FLPH Tibet Exped.13-2131 (PE).

FIGURE 9. Saussurea bhutanensis (A, B) and S. lhozhagensis (C) in the wild and living plants.