All Floras      Advanced Search
Flora of Taiwan Login | eFloras Home | Help
Flora of Taiwan | Family List | Compositae

Aster L.

紫菀屬

SOEJIMA, Akiko & PENG, Ching-I

Aster takasagomontanus

Credit: HAST

Mostly perennial herbs, subshrubs or shrubs, seldom annual or biennial herbs. Leaves simple, alternate, those of basal rosettes usually dissimilar to cauline leaves, those of peduncle often bract-like, mostly dentate. Heads heterogamous, solitary and terminal or variously corymbosely or paniculately arranged, radiate, rarely discoid. Involucral bracts in 2-6 imbricate, usually graduated series, margins herbaceous. Receptacle naked, often flat or convex, pitted or alveolate. Ray florets pistillate and fertile, in 1 (-2) series, ligules white, pink, blue or purple. Disc florets mostly yellow, all bisexual and fertile, corolla regular, narrowly tubular or funnelform, limb sometimes abruptly dilated at throat, 5-lobed. Anthers obtuse or subauriculate at base, with narrow scarious terminal appendages. Style of ray florets filiform, style of disc florets with flattened branches and linear-lanceolate, acute or acuminate appendages longer than stigmatic area. Achenes oblong-obovoid, mostly somewhat compressed, usually pubescent. Pappus usually in 1 row, similar in ray and disc florets, sometimes very short or absent, or only absent in ray florets, rarely in 2 rows with an outer row of shorter scale-like bristles.

A large, complex genus of more than 600 species, cosmopolitan in distribution. In Taiwan, about 16 species, one of which is represented by two varieties.


KEY TO SPECIES

1 Heads 5-6 mm across.   Aster subulatus
+ Heads more than 10 mm across.   (2)
       
2 (1) Biennial herbs; involucral bracts nearly equal long.   (3)
+ Perennial rhizomatous herbs; inner involucral bracts longer than outer except in A. takasagomontanus.   (5)
       
3 (2) Pappus uniform on ray and disc florets, 5 mm long.   Aster altaicus
+ Pappus dimorphic, 1 mm long on ray florets, 5 mm long on disc florets.   (4)
       
4 (3) Leaves oblanceolate to linear, apex acute or obtuse, hispidulous rarely glabrous.   Aster hispidus
+ Leaves elliptic-lanceolate to obovate, apex rounded to obtuse, nearly glabrous.   Aster oldhamii
       
5 (2) Small alpine plants, 5-20 cm tall.   (6)
+ Large plants 50-110 cm tall.   (9)
       
6 (5) Radical leaves spatulate; involucral bracts nearly equal long; heads 2.5-3.5 cm across.   Aster takasagomontanus
+ Radical leaves oblong to lanceolate, petiolate; inner involucral bracts longer than outer; heads less than 2 cm across.   (7)
       
7 (6) Stems to 5 cm tall.   Aster itsunboshi
+ Stems to 20 cm tall.   (8)
       
8 (7) Leaves oblong, apex acute.   Aster chingshuiensis
+ Leaves lanceolate, apex acuminate.   Aster morrisonensis
       
9 (5) Leaves narrowly ovate to oblong, long petiolate.   Aster formosanus
+ Leaves oblong to lanceolate, elliptic, or ovate, sessile or shortly petiolate.   (10)
       
10 (9) Radical leaves present at anthesis.   Aster taoyuenensis
+ Radical leaves withering at anthesis.   (11)
       
11 (10) Pappus 0.2-0.5 mm long.   (12)
+ Pappus 3-5 mm long.   (13)
       
12 (11) Stems 30-60 cm tall; leaves nearly glabrous or sparsely puberulous.   Aster indicus
+ Stems 50-100 cm tall; leaves hispidulous, rough to touch.   Aster shimadai
       
13 (11) Leaves pinnately nerved, glabrous.   Aster taiwanensis
+ Leaves conspicuously trinerved, not entirely glabrous.   (14)
       
14 (13) Leaves ovate; involucres turbinate.   Aster ovalifolius
+ Leaves oblong-lanceolate to lanceolate; involucres campanulate to hemispheric.   (15)
       
15 (14) Leaves scarcely puberulous or nearly glabrous.   Aster ageratoides
+ Leaves densely villose or hirsute.   Aster lasiocladus

  • List of lower taxa


     

    Related Objects  

    Flora of Chile  
  • PDF
  • PDF
    Flora of China  
  • PDF File: Aster
  • PDF
    Ornamental Plants From Russia And Adjacent States Of The Former Soviet Union  
  • Image/JPEG (Tatyana Shulkina)
  • Image/JPEG

  •  |  eFlora Home |  People Search  |  Help  |  ActKey  |  Hu Cards  |  Glossary  |