Aster brevicaulis W. P. Li, 2019

Xiao, Jia-Wei, Liao, Jun-Jie & Li, Wei-Ping, 2019, Aster brevicaulis (Asteraceae, Astereae), a new species from western Sichuan, China, Phytotaxa 399 (1), pp. 1-13 : 8

Aster brevicaulis W. P. Li , sp. nov. ( Figs. 2–4 )

Type.— CHINA. Sichuan, Yajiang County, Mt. Gaoersi, alt. 4,412 m, 101°20′ E, 30°30′ N, 31 July 2017, Wei-Ping Li LWP201707003 (holotype: HNNU) ( Fig. 4 ).

Diagnosis. — Aster brevicaulis differs from A. tongolensis by its stems only 2–15(22) cm long [(versus (3–)14–47(–60) cm in A. tongolensis ], stolons absent (versus present), phyllaries 5-seriate (versus 2- or 3-seriate), pappus 4–5 mm long (1.5–2 mm long) ( Table 1).

Description. —Herbs, perennial, 2–15(–22) cm tall, sometimes caespitose. Rhizomes slender, stolons absent. Stems erect, simple, somewhat slender, white below, reddish brown above, sparsely strigose or villous. Leaves basal and cauline, 3-veined above base (triplinerved); basal leaves 0.5–5(–6) × 0.2–1.1 cm, winged petiolate, petiole base subclasping, blade spatulate or obovate to oblanceolate, base attenuate, margin entire, apex obtuse to rounded, basal rosette present at anthesis; cauline leaves gradually reduced upward, sinuate; both surfaces sparsely short hispid or subglabrous, margin ciliate, veins conspicuous, midvein abaxially prominent; lower cauline leaves 1–3(–4.5) × 0.2– 0.6, sessile, oblong to linear-lanceolate, base subclasping, apex acute or obtuse, often undulate; middle and upper cauline leaves 0.7–2.5(–3) × 0.1–0.5cm, base subclasping, apex acute. Capitula terminal, solitary, 2.5–4.5 cm in diam. Involucres hemispheric, 7–13 mm; phyllaries 5-seriate, subequal, imbricate, herbaceous; abaxially sparsely to moderately villous, adxially pilose distally; margin narrowly to broadly scarious, villous-ciliate, apex obtuse to acute, tip sometimes purplish-red; outermost phyllaries oblong-linear, slightly recurved, 6.5–7.5 × 1.4–2 mm, second-seriate phyllaries oblong-linear, slightly recurved, 6–7 × 1.4–2 mm, third-seriate phyllaries oblong-linear, slightly recurved, 6.3–7.5 × 1.2–1.9 mm, fourth-seriate phyllaries oblong, slightly recurved, 6–7.1 × 1.3–1.9 mm, inmost phyllaries lanceolate, slightly recurved, 5.8–6.4 × 1–1.3 mm. Ray florets 18–40, slightly pendulous, blue or lavender to purplish; tube ca. 1.5 mm, sparsely hairy; lamina 10–20 × 2–3 mm, glabrous, eglandular. Disk florets 4–6 mm, orange; tube 1.4–1.6 mm, hairy; lobe 0.9–1.3 mm, narrowly triangular, recurved; stigmatic appendage (style branch appendage) lanceolate, ca. 0.7 mm, stigmatic lines 0.7–0.9 mm. Achenes ca. 2 × 1.5 mm, broadly obovoid, densely strigillose, 2- ribbbed. Pappus 1-seriate, red-brown, 4–5 mm, nearly as long as disk florets.

Phenology. —Flowering from July to August and fruiting from August to September.

Distribution and habitat. — Aster brevicaulis is known from location in Mt. Gaoersi and Mt. Zheduo, Sichuan Province, China. It grows at the alpine grasslands or shrub thickets at altitude of 3,800 –4,412 m.

Systematic position.— The results of our molecular phylogenetic analysis showed that the new species had close relationship with Aster tongolensis . It was treated as a member of A. subgenus Aster section Ageratoides (Kitamura) Nesom (1994: 247) , according to the infrageneric classification of Eurasian Aster by Li et al. (2012).

Etymology. —The specific epithet reflects the short stems in the new species, in comparison to the related A. tongolensis . Chinese name: AEḻṫ̎ (ai jing zi wan).

Additional specimens examined. — CHINA. Sichuan Province, Yajiang county, Mt. Gaoersi , alt. 4,412 m, 101°20′ E, 30°30′ N, 31 July 2017, Wei-Ping Li LWP1707007 & LWP1707006 & LWP1707005 & LWP1707004 & LWP1707002 ( HNNU) ; Sichuan Province, Kangding City, Mt. Zheduo , alt. 3,800–4,000 m, 101°46′ E, 30°04′ N, 3 August 2017, Wei-Ping Li LWP1708030 ( HNNU), 6 September 2015, Wei-Ping Li LWP1509061 & LWP1509065 & LWP1509067 & LWP1509070 & LWP1509073 .

Figures

FIGURE 2. Images of living plants of Aster brevicaulis. A: Habit; B: Individuals; C: Dorsal view of a capitulum; D: Involucre, showing the adaxial pilose; E: Top view of the capitulum.

FIGURE 3. Images of living plants of Aster brevicaulis. A: Basal leaves; B: Cauline leaves; C: Longitudinal section of a capitulum; D: A disk floret (left) and a ray floret (right); E: Style branches of a disk floret; F: Phyllaries from the innermost layer (left) to the outmost (right); G: Fruit (mature); H: Fruits.

FIGURE 4. Holotype of Aster brevicaulis W. P. Li.