Prepared by Jennifer L. D’Appollonio, Assistant Scientist, University of Maine, Orono, ME 04469. Updated February 2018.

Scientific name: Rhododendron canadense (L.) Torr.

Common name(s): rhodora, Canada rosebay

Links: USDA PLANTS Profile, NPIN Profile, Go Botany

Images: (to see enlargements [PC]: click on image, then right click and choose “view image”)


perennial, woody shrub

– flowers before and/or with leafout

– rose-purple flowers with two-lipped corolla emerge late May-early June in ME

-reaches 1’-3’ in height

-yellowish twigs

buds clusters at twig end and terminal buds have flowers larger than leaf buds

-leaves are

  • Alternate
  • oblong to elliptical
  • hairy leaves dark green above and light green beneath.


-Prefers bogs and poorly drained soils.

-disturbed sites

-meadows and fields

-shores of rivers

Wildlife uses:

– host plant for the Columbia silkmoth (Hyalophora columbia) in Maine

-attracts bees



Hansen, R.W., S.B. Hansen and E.A. Osgood. 1991. Reproductive phenologies of selected flowering plants in eastern Maine forests. ME Agric. Exp. Station Tech. Bull. 143. 17 pp.

Heinrich, B. 1976. Flowering phenologies: Bog, woodland, and disturbed habitats. Ecology. 57(5):890-899.

Go Botany. “Rhododendron Canadense (L.) Torr.” Rhododendron Canadense (Canada Rosebay, Rhodora): Go Botany, 2021, gobotany.nativeplanttrust.org/species/rhododendron/canadense/.