Matricaria discoidea - Pineapple Weed question

Hi all,

I’m curious as to why there is a discrepancy between reference sources about the native range of Matricaria discoidea - CalFlora says it is native to California (https://www.calflora.org/app/taxon?crn=11825), but iNat and Wikipedia says it is native to Asia and invasive in California. What’s going on there?

Thanks!
Ken

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It seems each source tells different things, it’s wither West NA or East Eurasia or both!

The Jepson Manual says “native to northwestern North America, northeastern Asia”. So, maybe native in northern California but spread into the rest of California.

“It is a northwestern North American native that has spread to eastern and northern North America and elsewhere (E. McClintock 1993b; E. G. Voss 1972–1996, vol. 3; A. Cronquist 1994). NatureServe (www.natureserve.org) and Natural Resources Conservation Service (plants.usda.gov) erroneously present M. discoidea as introduced on the continent. Its natural habitat is ill-defined because the species has become ruderal even in its native range.”

Luc Brouillet’s treatment in the Flora of North America.
http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=119860

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