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

Ixeris Cass.

苦藚菜屬

Ixeris polycephala

Credit: HAST

Low, usually glaucous annuals, biennials, or perennials; leaves radical and cauline, alternate, radical ones long petiolate. Heads small, few to many, on erect corymbosely branched stems; peduncle slender, ebracteate. Involucre tubular, bracts minute, in few series, glabrous, herbaceous, inner bracts all equal, linear, green, much larger and longer than outer calyculate bracts. Receptacle flat, naked. Corollas ligulate, truncate, yellow, white or purplish; ligule 5-toothed. Achenes glabrous, somewhat flattened, narrowly oblong, usually 10-ribbed, long beaked. Pappus bristles many, slender, scaberulous, nearly equal, silvery.

About 20 species in eastern and southeastern Asia. Taiwan, six species, one of which is represented by two subspecies.

  • Pak, J. H. & S. Kawano. 1992. Biosystematic studies on the genus Ixeris and its allied genera (Compositae-Lactuceae). IV. Taxonomic treatments and nomenclature. Mem. Fac. Sci. Kyoto Univ., Ser. Biol. 15: 29-61.
  • Yahara, Y. 1995. Ixeris Cass. In K. Iwatsuki, T. Yamazaki, D. E. Boufford & H. Ohba (eds.). Fl. Jap. 3(b): 15-19.


KEY TO SPECIES

1 Stolons elongate, stems scapiform.   (2)
+ Stolons wanting or short, stems usually leafy.   (4)
       
2 (1) Leaves trifoliolate or palmately 3- or 5-fid; outer involucral bracts prominent, 2/5 to 1/2 as long as inner ones.   Ixeris repens
+ Leaves ovate-orbicular or linear lanceolate, entire to runcinate-dentate or pinnatifid; outer involucral bracts calyculate, 1/5 to 1/3 as long as inner ones.   (3)
       
3 (2) Leaves ovate-orbicular, long petiolate.   Ixeris stolonifera
+ Leaves linear-lanceolate, attenuate at base.   Ixeris debilis
       
4 (1) Cauline leaves sagittate at base; heads nodding at maturity; achenes deeply sulcate.   Ixeris polycephala
+ Cauline leaves auriculate; heads erect at maturity; achenes shallowly grooved.   (5)
       
5 (4) Leaves radical and cauline; outer involucral bracts equal.   Ixeris chinensis
+ Leaves chiefly radical; outer involucral bracts somewhat unequal.   Ixeris tamagawaensis

Lower Taxa

Related Synonym(s):


 

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