Microseris is a genus of flowering plants in the tribe Cichorieae, within the large daisy family Asteraceae (order Asterales). The genus is native to a remarkably wide range, with species found across North America, South America, Australia, and New Zealand.
Plants in Microseris are either annuals or perennials. Most perennial species develop a taproot or caudex; an exception is Microseris borealis, which spreads by rhizomes. The leaves are mostly or entirely basal, lying close to the ground rather than being held up on erect stems. Flower heads are solitary, borne upright on slender stems both during flowering and when setting seed. The florets are yellow to orange and bear a strong superficial resemblance to dandelions, as is typical of many members of the chicory tribe.
The limits of the genus are actively debated among taxonomic authorities. Plants of the World Online (POWO) treats the genus Nothocalais as a synonym of Microseris, incorporating several species. The USDA PLANTS database, World Flora Online, the Global Compositae Database, and Flora of North America continue to recognise Nothocalais as a separate genus, placing species such as Microseris nigrescens (as Nothocalais nigrescens), M. alpestris, M. cuspidata, and M. troximoides outside Microseris under this treatment. GBIF recognises approximately 15 species in the genus.
Etymology
The name Microseris derives from the Greek mikros (small) and seris (a type of chicory or endive), referring to the plant's resemblance to small chicory-tribe plants.
Distribution
Microseris is native to North America, South America, Australia, and New Zealand, making it one of few genera in the chicory tribe (Cichorieae) with a disjunct distribution spanning both the Americas and Australasia.
Taxonomy Notes
The circumscription of Microseris is contested. POWO synonymises the closely related genus Nothocalais into Microseris, whereas USDA PLANTS, WFO, GCD, and Flora of North America (as of 2023) retain Nothocalais as a distinct genus. Under the broader treatment, species such as M. nigrescens, M. alpestris, M. cuspidata, and M. troximoides are included; under the narrower treatment, these are returned to Nothocalais.
