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Flora of Taiwan | Family List | Compositae

Ixeridium (A. Gray) Tzvelev


Ixeridium laevigatum

Credit: HAST

Perennial herbs with mainly rosulate, generally entire or sometimes dentate-pinnatifid leaves. Heads rather small, few-flowered, in loose corymbs. Involucral bracts in two unequal series. Florets yellow. Achenes narrowly oblong-terete to fusiform, with a distinct beak, ca. 10-ribbed, glabrous. Pappus brown, bristles scabrid-barbellate.

About 15 species from eastern and southeastern Asia to New Guinea; two species in Taiwan.

Based mainly on cytology and achene anatomy, Pak & Kawano (1992) split Ixeris into Ixeridium and Ixeris. Ixeridium has a basic chromosome number of n = 7 and a brown pappus; Ixeris has a basic chromosome number of n = 8 and a white pappus. Their treatment is accepted here.

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.


1 Inner involucral bracts 8-10, rarely 5; floret 8-11; pappus ca. 2.5-3 mm long.   Ixeridium laevigatum
+ Inner involucral bracts 5, rarely to 7; floret 5-7; pappus ca. 4-5 mm long.   Ixeridium transnokoense

Lower Taxa

Related Synonym(s):


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