Saussurea pseudorockii Y.S. Chen, 2014

Chen, You-Sheng, 2014, Five new species of Saussurea (Asteraceae, Cardueae) from the Hengduan Mountains region, southwestern China, Phytotaxa 170 (3), pp. 141-154 : 145-146

3. Saussurea pseudorockii Y.S. Chen , sp. nov. ( Figs. 3 & 6B )

Type:— CHINA. Yunnan: Gongshan, Bingzhongluo, mountains above Chunganchu lake , 3900 m, alpine meadows among rocks, 5 September 2009, Y. S . Chen 9730 (holotype PE; isotypes PE) .

Perennial herbs, nearly stemless. Rhizome usually branched, ascending, densely covered with dark brown residue of old leaves. Leaves rosulate or cauline, subsessile; leaf blade linear, 10–22 cm × 4–6 mm, chartaceous, abaxially green, glabrous, adaxially sericeous-tomentose except for midrib, base slightly attenuate, then expanded into a sheath, apex acute, margin entire; midrib conspicuous on both surfaces. Capitula solitary in rosette of leaves at end of stem, sessile, 1.5–2.5 cm in diameter and 2.3–3 cm high. Phyllaries in ca. 4 rows, subequal, imbricate, chartaceous, abaxially subglabrous; outer phyllaries green, triangulate-oblong, 19–25 × ca. 4 mm, apex acuminate; middle phyllaries brownish, oblong, 19–21 × ca. 4 mm, apex acuminate; inner phyllaries lanceolate, ca. 20 × 2.5 mm, apex acute. Receptacle flat, densely covered with persistent yellowish bristles, bristles linear, 7–8 mm long. Florets numerous; corolla purple, tubular-funnelform, glabrous, tube ca. 1 cm long and ca. 0.2 mm in diameter, limb (including lobes) ca. 6 mm long and ca. 1 mm in diameter, with 5 lobes ca. 3.5 mm long; anthers ca. 5 mm long. Achenes cylindroid, blackish brown, glabrous, ca. 5 × 1 mm, with 5–7 distinct longitudinal ribs, apex with a conspicuous denticulate crown, base truncate. Pappus heteromorphic, biseriate, blackish brown, outer series of scabrid bristles 2.5–3 mm long, falling off individually; inner series of 14–18 yellowish white plumose bristles 15–18 mm long, connate at base into a ring, falling off as a whole.

Distribution and habitat:— Saussurea pseudorockii is currently known only from Gongshan County, northwestern Yunnan, China. It grows in alpine meadows among rocks at an altitude of 3900 m.

Phenology:—Flowering from August to September.

Etymology:—The specific epithet is derived from the name of its putative closest ally, Saussurea rockii Anthony (1934: 211) .

Discussion:— Saussurea pseudorockii is readily referable to S. subgen. Saussurea sect. Lagurostemon ( Cassini 1828: 466) Candolle (1838: 532) on an account of its leaf blade linear, entire, and grasslike, and the capitula solitary, 1.5–2.5 cm in diameter. The new species is most closely related to S. rockii which is distributed in Gongshan and Lijiang Counties of northwestern Yunnan, China at altitudes of 2700–3900 m, but the latter species differs by its stem usually distinct, 6–12 cm high, leaves usually shorter (5–7 cm long), abaxially sparsely pilose, margin usually remotely and obscurely mucronate, capitula 1–2 cm in diameter, phyllaries pilose in the upper part, outer phyllaries lanceolate, ca. 3 mm wide, and inner pappus shorter (7–10 mm long).

Saussurea pseudorockii is also similar to S. romuleifolia Franchet (1888: 339) which is widely distributed in northwestern Yunnan, western Sichuan and southeastern Xizang at altitudes of 2200–4000 m but differs in the stem very short, the plant being even nearly stemless, capitula 1.5–2.5 cm in diameter, leaves 4–6 mm wide, and phyllaries glabrous and acuminate at apex. Saussurea romuleifolia is distinct by its stem usually 10–40 cm tall (rarely abbreviated), capitula 2–3.5 cm in diameter, leaves usually 1–2 mm wide (rarely 5 mm wide), and phyllaries sericeous and long acuminate at apex.

Figures

FIGURE 3. Saussurea pseudorockii. A. Habit. B. Floret, with the pappus removed. C. Inner pappus. D. Outer pappus. E. Style branches. F. Leaf section. G. Floret with pappus. H. Phyllaries (from left to right, outer to inner series). I. Anther. All from Y.S. Chen 9730 (PE). Illustration by Mr.Y.X. Zhu.

FIGURE 6. Saussurea fuscipappa (A) and S. pseudorockii (B) in the wild.