Aster quanzhouensis M.Tang, G.J.Yan & W.P.Li, 2022

Xiao, Jia-Wei, Yan, Guo-Jiao, Li, Wei-Ping & Tang, Ming, 2022, Aster quanzhouensis (Asteraceae), a new riparian species from eastern China, PhytoKeys 195, pp. 93-106 : 93

Aster quanzhouensis M.Tang, G.J.Yan & W.P.Li sp. nov.

Figs 1 , 2 , 3

Type.

China, Fujian province, Quanzhou city, Dehua county, Nancheng town , alt. ca. 500 m, 25°34.20'N, 118°29.65'E, 5 Oct 2021, Guo-Jiao Yan, YGJ2110003 (Holotype: HNNU!, isotypes: HNNU!, JXAU!) (Fig. 3 ) .

Additional collection seen.

China. Fujian province, Quanzhou city, Yongchun county, alt. ca. 500 m, 25°24'N, 118°21'E, 30 Nov 2021, Guo-Jiao Yan, YGJ21113001 ( HNNU!).

Diagnosis.

Aster quanzhouensis differs from A. tonglingensis by its stems only 21-30 (60) cm (vs. 70-100 cm) long, narrowly lanceolate (vs. lanceolate) rosulate leaves, purplish-red (vs. green) apices of the phyllaries, 9-20 (40) (vs. more than 30) capitula, 7-11 (vs. ca. 15) ray florets, 11-14 × ca. 2 mm (vs. 7-10 × ca. 2 mm) lamina, two-or three-ribbed (vs. 4-ribbed) achenes and flowering period (Sep to early Dec vs. Jul) (Figs 2 , 3 , Table 1 ).

Description.

Perennial herb, 21-30 (60) cm high. Rhizomes thin, with adventitious roots, stolons absent. Stem solitary, erect, unbranched except for inflorescence, glabrous or puberulent in upper part. Leaves slightly leathery, narrowly lanceolate, apex acute, base gradually narrowing, subclasping, abaxially light green, adaxially dark green and glossy, 3-veined, midvein abaxially prominent; rosulate leaves 4-13 × 0.4-1.7 cm, margin serrate, petiole 3-11 cm long, both surfaces glabrous; lower cauline leaves persistent at anthesis or rarely withered, 3-10 × 0.3-0.8 cm, sessile or with obscure petioles, margin entire or serrate, abaxially glabrous, adaxially sparsely strigose; middle cauline leaves sessile or with obscure petiole, 4-7 × 0.3-0.4 cm, margin entire or serrate, abaxially glabrous, adaxially sparsely strigose; upper leaves sessile, margin entire. Capitula 9-20 (40) in a terminal corymbose cyme, peduncle puberulent. Involucre campanulate, 5-8 mm in diameter; phyllaries in 5-7 rows, imbricate, lanceolate, the outer rows shorter than the inner ones, reflexed, densely pilose, with ciliate margin; outer phyllaries 3.2-6.2 × 1.1-2 mm; middle phyllaries 4.6-13 × 1.5-2.2 mm, with narrowly scarious margin, tip purplish-red; inner phyllaries 10.1-13.0 × 1.5-1.7 mm, with broadly scarious margin, tip purplish-red. Receptacles flat, alveolate. Ray florets 7-11, female, tube ca. 4 mm, glabrous, ligules whitish, lanceolate, 11-14 × ca. 2 mm, with four nerves, apex with two or three teeth. Disc florets (11) 18-24, hermaphrodite, yellow, tube puberulent, ca. 3 mm, thin but expanded at base, 5-lobed, lobes spreading to reflexed, narrowly triangular, unequal, 1.1-1.5 mm, glandular; anthers ca. 1.8 mm (excluding collar), apical appendage 0.35-0.45 mm long, narrowly lanceolate, anther collar ca. 0.4 mm long; style arm appendage lanceolate, ca. 2.5 mm, stigmatic lines 1.2-1.4 mm, equal to the sterile style tip appendages. Achenes 4.5-5.5 × 0.9-1.4 mm, narrowly oblong, strigose, eglandular, two- or three-ribbed. Pappus uniseriate, dirty white, 8-11 mm, nearly as long as disc corolla at anthesis.

Phenology.

Flowering from September to early December and fruiting from October to December.

Etymology.

The species is named after its type locality, Quanzhou city, Fujian province, China.

Vernacular name.

quán zhōu zĭ wăn (Chinese pronunciation); 泉州紫菀 (Chinese name).

Distribution and habitat.

Aster quanzhouensis is known from Dehua and Yongchun counties, Quanzhou city, Fujian province, China. The new species grows on rocks in riparian habitats at an altitude of ca. 500 m a.s.l.

Conservation status.

Aster quanzhouensis seems to be a narrowly distributed species, currently known only in rocky areas along two streams (Jin river and Min river) in Quanzhou city, and each population with ca. 150 (total < 1000) individuals were found. The habitat of A. quanzhouensis is easily disturbed or damaged. Further fieldwork is needed to evaluate the exact distribution of the species, and it is possible that other populations could be found in similar habitats of the Jin and Min rivers. Therefore, we only temporarily assign the species to the category DD (Data Deficient) according to the International Union for Conservation of Nature ( IUCN 2022).

Cytology

The somatic chromosomes of the new species at metaphase are illustrated in Fig. 4 . The two populations have a same karyotype formula, 2n = 18, and Stebbins’ 1A-type ( Stebbins 1971), but differs in ratio of long to short arm of chromosomes (the former is 1.02-1.55, while the latter 1.06-1.45), the chromosomes length (the former is 1.49-2.72, while the latter 1.71-2.77), and the AI value (the former is 0.54, while the latter 0.57).

Molecular phylogeny

The aligned lengths of ITS, ETS and trnL-F are 647 bp, 568 bp and 957 bp, respectively, yielding a concatenated alignment of 2172 bp. Character state changes were equally weighted and gaps were treated as missing data. ML and BI analyses produced similar topology and only the ML tree was presented in Fig. 5 , with ML bootstrap (LP), and PP values for each clade. The phylogenetic results showed that the two samples of the new taxon were grouped together with strong support (PP = 1.00, LP = 100%) and are closely related to Aster tonglingensis with strong support (PP = 1.00, LP = 99%). According to these results, A. quanzhouensis is nested within the core Aster clade (PP = 1.00, LP = 100%) that is the redefined genus Aster in Eurasia ( Li et al. 2012; Nesom 2020a, b).

Figures

Figure 1. Distribution of Aster quanzhouensis (black circle) and A. tonglingensis (black triangle).

Figure 2. Images of living plants of Aster quanzhouensis A habitat B habit C seedling D steam E rosulate leaves F top view of the capitulum G a disk floret (left) and a ray floret (right) H style branches of a disk floret I receptacle J fruits K dorsal view of a capitulum L phyllaries (from outer to inner, left to right).

Figure 3. Holotype of Aster quanzhouensis M. Tang, G. J. Yan & W. P. Li.

Figure 4. Micrographs of somatic metaphase chromosomes (A, C) and the karyotype (B, D) of Aster quanzhouensis from two different populations. (A, B Dehua county, Quanzhou, Fujian, China; C, D Yongchun county, Quanzhou, Fujian, China).

Figure 5. The phylogram of the maximum likelihood (ML) tree from the combined data (ITS, ETS and trnL-F), showing the phylogenetic position of Aster quanzhouensis. Bootstrap support values (1,000 replicates) for maximum parsimony (MP ≥ 50 %, left) and Bayesian posterior probabilities (PP ≥ 0.90, right) are provided above the branches. The samples of Aster quanzhouensis are shown in bold.