Aster sect. Aster in Flora of China @ efloras.org

6. Aster sect. Aster

紫菀组 zi wan zu

Gymnaster Kitamura (1937), not F. Schütt (1891) [Algae]; Kitamuraea Rauschert; Kitamuraster Soják; Leptocoma Lessing; Miyamayomena Kitamura; Rhynchospermum Reinwardt; Zollingeria Schultz Bipontinus.

Herbs, perennial, usually simple, sometimes branched, erect. Leaves basal (withered at anthesis) and cauline; blade spatulate or ovate to narrowly ovate or lanceolate, sometimes pandurate, margin flat, entire or serrate to coarsely serrate, 1-veined (rarely 3-veined). Capitula radiate, rarely discoid, terminal, numerous, in corymbiform synflorescences, rarely few, rarely solitary at ends of branches or in leaf axils. Involucres hemispheric, campanulate, or obconic, to cylindric-campanulate; phyllaries 3-7-seriate, unequal or sometimes subequal, membranous (upper part sometimes leaflike) or outer leaflike, not keeled, margin scarious. Receptacles flat or ± convex, rarely conic. Ray florets 1(or 2)-seriate, 10-40, purple, blue, lavender, pink, or white; disk floret limb campanulate or sometimes funnelform, lobes equal. Achenes obovoid or oblong to oblanceoloid, ± compressed, 2-6-ribbed. Pappus of ray and disk florets 1-4-seriate, of persistent, rarely caducous, numerous free bristles, innermost series clavate, outermost series of short bristles, rarely of scales, sometimes absent in ray and/or disk florets.

About 60 species: Asia, Europe; 49 species (40 endemic) in China.

As circumscribed here, Aster sect. Aster is paraphyletic to A. sect. Alpigeni (Brouillet et al. in Funk et al., Syst. Evol. Biogeogr. Compositae, 589-629. 2009). The separation of A. sect. Aster and A. sect. Orthomeris Torrey & A. Gray (Y. Ling & Y. L. Chen, FRPS 74: 134, 157. 1985) is unclear, and data supporting the segregation of monophyletic groups within the section are insufficient at the present time. Removal of the shrubby species of A. ser. Albescentes (Incertae sedis group above) renders the group more natural. Furthermore, the name A. sect. Orthomeris belongs to the North American Oclemena Greene (Brouillet, Fl. N. Amer. 20: 78-81. 2006) and would be inappropriate in Aster s.s.

A hitherto unrecognized group of species within Aster sect. Aster (formerly part of A. sect. Orthomeris, see Y. Ling & Y. L. Chen, loc. cit.) was identified in molecular phylogenies (Brouillet et al., loc. cit.), where it appeared to be sister to members of A. sect. Alpigeni. The group also includes Miyamayomena and Rhynchospermum. Morphologically, it is characterized by distally unreduced or slightly reduced cauline leaves that are abaxially pale and often appearing spongy on the surface; some species are glabrous, but most are hairy with minutely stipitate glands that are often (but not always) found in shallow pits and produce an abundance of resin, making the surface or parts of the surface vernicose. Some members of the group have a caducous pappus (Rhynchospermum) or have lost the pappus of ray and/or disk achenes (Miyamayomena). Further phylogenetic work is necessary to determine the monophyly and limits of this group.

1 Leaf surfaces (both) glabrous (sometimes abaxial veins sparsely strigillose), eglandular; leaves thick, margin revolute (2)

+ Leaf abaxial and/or adaxial surfaces hairy or glandular; leaves thick or thin, margin flat or revolute (4)

2 (1) Capitula solitary in leaf axils or terminal, overall forming a paniculose-corymbiform synflorescence; pappus dirty white. 65 A. hunanensis

+ Capitula in corymbiform synflorescences; pappus reddish or yellowish (3)

3 (2) Leaves abaxially with 3 or 4 pairs of lateral veins joining to form a raised submarginal vein on each side; achenes 4-ribbed; pappus reddish. 49 A. dolichophyllus

+ Leaves with lateral veins 2- or 3-paired; achenes 2-ribbed; pappus yellowish. 50 A. moupinensis

4 (1) Abaxial leaf surface minutely stipitate glandular in pits (5)

+ Abaxial leaf surface eglandular or glandular (but not in pits) (23)

5 (4) Pappus absent in all achenes, or absent in ray and of scales in disk achenes (6)

+ Pappus present in all achenes (12)

6 (5) Disk pappus of short scales. 58 A. piccolii

+ Disk pappus absent (7)

7 (6) Ray achenes long beaked. 64 A. verticillatus

+ Ray achenes not beaked (8)

8 (7) Achenes inconspicuously ribbed; leaf margin entire (9)

+ Achenes 2-4- to multiribbed; leaf margin ± serrate or crenate (10)

9 (8) Stems and leaves hispidulous-villous; middle leaves oblong-lanceolate or subelliptic, 1.5-2.5(-4) × 0.3-0.6(-0.9) cm; ray florets ca. 16 mm. 60 A. pseudosimplex

+ Stems hirsutulous, leaves strigose; middle leaves lanceolate-ovate to narrowly oblong or linear, 1-3 × 0.1-0.6 cm; ray florets 5-7 mm. 61 A. lixianensis

10 (8) Leaf margin coarsely serrate to serrate. 59 A. yuanqunensis

+ Leaf margin remotely serrate, serrulate, or obscurely repand-crenate (11)

11 (10) Middle leaf blades oblanceolate to narrowly lanceolate, margin remotely serrate to serrulate. 62 A. sinoangustifolius

+ Middle leaf blades ovate, broadly elliptic, or obovate, margin obscurely repand-crenate. 63 A. lushiensis

12 (5) Ray achenes long beaked. 64 A. verticillatus

+ Ray achenes not beaked (13)

13 (12) Phyllary abaxially with midvein plus 3-7 dark green striae; peduncle bracts crowded below head, often grading into phyllaries. 73 A. falcifolius

+ Phyllary without dark green striae; peduncle bracts not grading into phyllaries (14)

14 (13) Capitula terminal, solitary (rarely 2) on branches. 69 A. molliusculus

+ Capitula few to many (rarely 1) in terminal corymbiform synflorescences (15)

15 (14) Involucres cylindric-campanulate (16)

+ Involucres campanulate to hemispheric (18)

16 (15) Ray florets purple. 55 A. alatipes

+ Ray florets white (17)

17 (16) Phyllaries 3- or 4-seriate; leaf blade ovate, base cordate. 48 A. formosanus

+ Phyllaries 5-7-seriate; leaf blade obovate to oblanceolate, base attenuate. 51 A. taiwanensis

18 (15) Phyllaries 3- or 4-seriate, unequal (19)

+ Phyllaries 2- or 3-seriate, subequal (21)

19 (18) Ray florets purple. 36 A. veitchianus

+ Ray florets white (20)

20 (19) Lower leaf margin coarsely 3- or 4-serrate distally, teeth pointing forward. 53 A. taoyuenensis

+ Lower leaf margin crenate-serrate. 57 A. morrisonensis

21 (18) Ray florets 10-14; capitula 1-10. 54 A. homochlamydeus

+ Ray florets 25-35(-60); capitula 10 to numerous (22)

22 (21) Ray florets 30-35(-60); achenes 4-ribbed. 70 A. sikkimensis

+ Ray florets 25-30; achenes 2-ribbed. 72 A. nigromontanus

23 (4) Subshrubs or woody perennial herbs (24)

+ Herbs perennial (26)

24 (23) Phyllaries 3-seriate, unequal to subequal; leaf blades lanceolate, 4-7.5[-10] cm; ray florets 21-25. 46 A. smithianus

+ Phyllaries 4- or 5-seriate, unequal; leaf blades linear-oblong, oblong, or oblong-lanceolate to elliptic, 0.5-2.5(-3) cm; ray florets 10-20 (25)

25 (24) Leaf and phyllary surfaces strigose, villous; involucres cylindric-campanulate; phyllaries ± leaflike. 42 A. poliothamnus

+ Leaf and phyllary surfaces densely velutinous; involucres hemispheric; phyllaries membranous. 43 A. sikuensis

26 (23) Phyllaries 2- or 3-seriate, subequal, outer usually leaflike (if sometimes unequal then outer leaflike) (27)

+ Phyllaries 3-7-seriate, unequal, leaflike in upper part or not leaflike (notably if subequal) (35)

27 (26) Ray florets purple, mauve, pink, or blue; achenes obovoid (28)

+ Ray florets white; achenes oblong or oblanceoloid, rarely obovoid (31)

28 (27) Involucres hemispheric; ray florets 50-60. 44 A. taliangshanensis

+ Involucres campanulate to broadly campanulate; ray florets 13-30 (29)

29 (28) Leaf blade broadly ovate or oblong to lanceolate, base cordate or rounded, margin coarsely serrate to serrate; achenes 4-ribbed, pappus red-brown; disk corolla limb funnelform. 34 A. fuscescens

+ Leaf blade oblanceolate, base attenuate to cuneate or rounded, margin entire or serrulate to serrate or coarsely serrate; achenes 2-ribbed, pappus dirty white or straw-colored; disk corolla limb campanulate (30)

30 (29) Ray florets mauve or pink; pappus dirty white; leaf surfaces scabridulous. 31 A. indamellus

+ Ray florets blue; pappus straw-colored; leaf abaxially villosulous, adaxially strigillose. 39 A. trichoneurus

31 (27) Herbs scapiform; leaves basal, rosulate; capitula 1 or 2, terminal. 68 A. itsunboshi

+ Herbs erect; leaves cauline; capitula 2 to numerous in terminal corymbiform synflorescences (rarely solitary) (32)

32 (31) Middle leaf base auriculate, clasping; ray florets 18-30. 35 A. auriculatus

+ Middle leaf base cuneate, rounded, or attenuate; ray florets 10-20 (33)

33 (32) Leaf base cuneate to rounded, apex obtuse or rounded, margin revolute, entire. 40 A. mangshanensis

+ Leaf base attenuate, apex acute to acuminate, margin flat, ± serrate or entire (34)

34 (33) Leaf blade ovate to ovate-lanceolate, midvein prominent. 45 A. procerus

+ Leaf blade oblong-lanceolate, triplinerved. 66 A. menelii

35 (26) Leaf margin revolute, entire or ± serrate (36)

+ Leaf margin flat, coarsely serrate or serrate to serrulate or entire (40)

36 (35) Pappus white or dirty white (innermost reddish) (37)

+ Pappus reddish brown or orangish (38)

37 (36) Middle leaf blade oblanceolate to ovate, base cuneate-rounded to rounded; ray florets white; pappus dirty white (innermost reddish). 52 A. chingshuiensis

+ Middle leaf blade narrowly lanceolate to linear-lanceolate, base attenuate; ray florets blue-purple; pappus white. 67 A. gracilicaulis

38 (36) Middle leaf abaxial surface tomentose; phyllaries 3-seriate. 41 A. vestitus

+ Middle leaf abaxial surface velutinous or moderately scabridulous, strigose; phyllaries 4-6-seriate (39)

39 (38) Middle leaves sessile or shortly petiolate, blade lanceolate, abaxially velutinous. 77 A. velutinosus

+ Middle leaves winged petiolate, blade ovate to linear-obovate, abaxially moderately scabridulous, strigose, minutely stipitate glandular. 79 A. sampsonii

40 (35) Ray florets white (41)

+ Ray florets purple (44)

41 (40) Abaxial leaf surface moderately scabrous or moderately strigose, adaxial surface scabrous, margin serrate or serrulate; phyllaries 5-7-seriate (42)

+ Abaxial leaf surface ± hispidulous, adaxial surface sparsely puberulent or hispidulous, margin entire to subentire or sparsely serrate; phyllaries 4- or 5-seriate (43)

42 (41) Middle leaf blade pandurate or ovate to ovate-lanceolate, base truncate or rounded to auriculate-clasping; capitula 1-10 in racemiform synflorescences; involucres 10-12 mm. 74 A. turbinatus

+ Middle leaf blade narrowly ovate to lanceolate, base attenuate to rounded; capitula numerous in corymbiform to paniculiform synflorescences; involucres 6-7 mm. 75 A. baccharoides

43 (41) Middle leaf blade oblong or oblong-elliptic, base attenuate. 76 A. sinianus

+ Middle leaf blade ovate, base rounded. 78 A. ovalifolius

44 (40) Middle leaf blade cordate, reniform, or subrounded, cordate-ovate. 56 A. limosus

+ Middle leaf blade pandurate or ovate to ovate-lanceolate, lanceolate, or linear-lanceolate (45)

45 (44) Middle and upper leaves petiolate; disk corolla limb funnelform, lobes lanceolate; achenes lanceoloid. 71 A. pycnophyllus

+ Middle and upper leaves winged petiolate or sessile; disk corolla limb campanulate, lobes narrowly triangular; achenes obovoid (46)

46 (45) Phyllaries 5- or 6-seriate; involucres 10-12 mm. 74 A. turbinatus

+ Phyllaries 3- or 4-seriate; involucres 4-10(-12) mm (47)

47 (46) Involucres 7-10(-12) mm (48)

+ Involucres 4-6 mm (50)

48 (47) Middle leaf blade ovate or pandurate to lanceolate-pandurate, base attenuate or auriculate, clasping. 37 A. sphaerotus

+ Middle leaf blade oblanceolate to ovate or lanceolate, base attenuate (49)

49 (48) Leaf midvein prominent; phyllary apex acute or acuminate; ray florets 14-30; achenes 4-6-ribbed. 32 A. tataricus

+ Leaf 3-veined; phyllary apex obtuse to rounded; ray florets 30-40; achenes 2-ribbed. 33 A. maackii

50 (47) Middle leaves sessile, blade lanceolate to linear-lanceolate, apex acuminate; pappus white. 47 A. dolichopodus

+ Middle leaves winged petiolate or sessile, blade ovate or pandurate to lanceolate- pandurate or elliptic to oblanceolate, apex obtuse or acute; pappus reddish (51)

51 (50) Middle leaf blade ovate or pandurate to lanceolate-pandurate. 38 A. panduratus

+ Middle leaf blade ovate to elliptic or oblanceolate. 41 A. vestitus

List of lower taxa