Botany Photo of the Day will have brief written entries on weekends, holidays and my vacations from April through September. – Daniel
Thank you once again to Anne from Alberta (aka annkelliott@Flickr) for sharing one of her photographs with us (original via BPotD Flickr Group Pool).
A native of Europe, orange hawkweed is a problem plant in other parts of the world despite its beauty (the list of Idaho’s Noxious Weeds makes an assertion that “distribution of this weed has likely been assisted by flower enthusiasts due to its beauty”).
Wikipedia has more links, though it uses a different scientific name for the species, Pilosella aurantiaca (I’ve opted to use what is currently accepted by GRIN taxonomy).

A general comment: I would love it if the descriptions would include some idea of scale/how big the featured plant is. It makes a difference whether this bloom is as big as a florist’s proteus, or small like a Lily of the Valley. Thanks! I love this service.
Key to Identification of Native and Invasive Hawkweeds in the PNW by L. Wilson:
http://www.for.gov.bc.ca/hfp/publications/00230/Hawkweed%20key_PNW_R3-June06.pdf
For clarification, Pilosella aurantiaca is the accepted name in its native area, e.g. BSBI database, Fl. NW Europe: http://ip30.eti.uva.nl/BIS/flora.php?selected=beschrijving&menuentry=soorten&id=3953
“It makes a difference whether this bloom is as big as a florist’s proteus, or small like a Lily of the Valley”
The flowerheads are 10-25mm diameter.