Saussurea zogangensis 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 : 168

5. Saussurea zogangensis Y. S. Chen , sp. nov. ( Fig. 5 )

Type:— CHINA. Xizang: Zogang County, Dongdala Shan pass, alpine scree, 5000 m, 21 August 2009, Y. S. Chen 9502 (holotype PE; isotype PE) .

Herbs perennial, 3–10 cm tall, polycarpic, sometimes caespitose. Caudex branched at underground level, usually with many leaf rosettes and flowering shoots. Stem erect, grayish white arachnoid tomentose, 4–5 mm in diameter, usually concealed by leaves. Basal leaves narrowed into short petioles; leaf blade oblong or spatulate, 2–5 cm long, 3–12 mm wide, both surfaces white tomentose, margin crenate to entire, apex obtuse; middle stem leaves similar. Uppermost leaves crowded, sessile, triangular-ovate, usually reflexed, base enlarged, enveloping synflorescence. Synflorescence hemispheric, 2.5–4 cm in diameter, exposed at anthesis. Capitula 10–25, nearly sessile, congested on top of stem. Involucre cylindroid, 5–6 mm in diameter. Phyllaries in ca. 3 rows, subequal, membranous; outer phyllaries narrowly obovate-elliptic, 9–10 mm long, ca. 3 mm wide, densely blackish brown woolly over all surfaces, apex subacute; middle phyllaries obovate-elliptic, 9–10.5 mm long, ca. 3 mm wide, margin hyaline, apically blackish brown woolly, apex purplish brown, acute; inner phyllaries elliptic, ca. 10 mm long, ca. 2 mm wide, margin hyaline, apically blackish brown woolly, apex purplish brown, acute. Receptacle bristles yellowish brown, acerose, 2–3 mm long. Corolla pink, 10–11 mm long, tube 4.5–5 mm long, limb ca. 6 mm long, lobes 3–4 mm long. Anthers ca. 4.5 mm long including tails; tails densely ciliate, ca. 0.4 mm long. Achenes oblong-cylindroid, 3–5 mm long, ribbed, glabrous, apex with a short rim. Pappus black; outer bristles scabrid, 3–4 mm long; inner bristles 16–20, long plumose, ca. 10 mm long.

Distribution and habitat:— Saussurea zogangensis occurs in eastern Xizang (Tibet), China. It grows in alpine scree slopes at altitudes of 4400–5000 m.

Phenology:—Flowering and fruiting from August to September.

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

Additional specimens examined (paratypes):— CHINA. Xizang: Riwoqê to Qamdo pass, alpine scree slopes, 4800 m, 8 August 2010, Kham Expedition 10-1513 ( PE) ; Baxoi County, Ranwu, Demula Shan , 4800 m, 24 August 1973, Qinghai-Xizang Expedition 1227 ( KUN, PE) ; Baxoi County, Ranwu, Demula Shan pass, 4400–4900 m, 3 September 1983, B. S. Li & S. Z. Cheng 7344 ( PE) .

Discussion:— Saussurea zogangensis belongs to S. subgen. Eriocoryne because of its capitula in densely congested hemispheric synflorescence and surrounded by densely lanate subtending leaves. In our molecular tree, it is shown to be closely related to S. inversa Raab-Straube (2011: 92) . It is similar to S. inversa in its polycarpic habit, short stem, synfloresence hemispheric, phyllaries in ca. 3 rows and subequal, pappus black, and in the size and shape of leaf blade as well, but differs by its corolla pink (vs. rose-purple), outer pappus erect (vs. reflexed and appressed on achene). It is also similar to S. sorocephala (Schrenk ex Fischer & Meyer 1841: 43) Schrenk (1842: 38) in its short stem, polycarpic habit, leaf size, shape, margin and indumentum, uppermost leaves crowded, sessile, triangular-ovate, base enlarged, enveloping synflorescence, synfloresence hemispheric, phyllaries in ca. 3 rows and subequal, pappus black, and in the leaf size, shape, margin and indumentum, but differs by its corolla pink (vs. light bluish white), synfloresence with 10–25 capitula (vs. 7–10 capitula). Saussurea sorocephala has been previously often treated as a synonym of S. gnaphalodes (Royle ex Candolle 1838: 542) Schultz Bipontinus 1846: 331 ) ( Lipschitz 1979; Shi & Jin 1999; Shi & Raab-Straube 2011). However, we found that S. sorocephala is a distinct species after checking its type material and living plants in the field. A comparison of S. zogangensis with related species is given in Table 4.

Figures

FIGURE 5. Saussurea zogangensis. A. Habit. B. Cross section of leaf. C. Phyllaries (from left to right, outer to inner series). D. Floret. E. Outer pappus bristle. F. Inner pappus bristle. G. Floret (with pappus removed). H. Anthers. I. Style branches.All from Y. S. Chen 9502 (PE). Drawn by Mr. Y.X. Zhu.