Rhododendron Linnaeus. Common name: Rhododendron, Azalea.
A genus of about 860 species, shrubs and trees, mostly north temperate (centered in Himalayan Asia). Molecular evidence appears to show that Menziesia should be included in Rhododendron, and is actually closely related within Rhododendron to R. vaseyi (Goetsch, Eckert, & Hall 2005; Kurashige et al. 2001); while the urceolate corolla is rather anomalous in Rhododendron, many other morphological characters do ally Menziesia with "basal" clades in Rhododendron s.l.
Considerable additional work is needed to clarify Rhododendron taxonomy in our region. Additional entities appear to warrant recognition in the "Viscosum complex" and the "Canescens complex"; these will be more thoroughly tackled in the next edition.
Key advice:This key makes as much use as possible of vegetative characters, geography, and capsule characters; capsules are generally available for longer during the year than flowers, and even when plants are in flower, last year's capsules can often be found.
References: Albach & Bauer (2021); Chamberlain (1982); Craven (2011); Cullen (1980); Davidian (1982); Duncan & Pullen (1962); Fabijan (2009a) In Flora of North America Editorial Committee (2009); Goetsch, Eckert, & Hall (2005); Horn (2019); Horn (2023); Judd & Kron (1995); Judd & Kron (2009a) In Flora of North America Editorial Committee (2009); Kron (1993); Kron & Creel (1999); Miller (2011); Miller (2012); Stevens et al. (2004) In Kubitzki et al. (2004); Towe (2004); Wilson & Rehder (1921); Zhou et al. (2008). Show full citations.
Hover over a shape, letter, icon, or arrow on the map for definition or see the legend. Data for arrows not developed for genera and families which may have species only occurring outside the flora area.
© Gary P. Fleming | Rhododendron catawbiense | Original Image ⭷
© Richard & Teresa Ware | Rhododendron pilosum CC-BY-NC, permission granted to NCBG | Original Image ⭷
© Erik Danielson | Rhododendron prinophyllum source | Original Image ⭷
© Gary P. Fleming | Rhododendron prinophyllum | Original Image ⭷
© Erik Danielson | Rhododendron maximum source | Original Image ⭷
© Alan M. Cressler | Rhododendron arborescens | Original Image ⭷
© Scott Ward | Rhododendron groenlandicum | Original Image ⭷
© Gary P. Fleming | Rhododendron catawbiense | Original Image ⭷
© Scott Ward | Rhododendron austrinum | Original Image ⭷
© Gary P. Fleming | Rhododendron prinophyllum | Original Image ⭷
© Keith Bradley | Rhododendron flammeum | Original Image ⭷
© Keith Bradley | Rhododendron carolinianum | Original Image ⭷
© Richard & Teresa Ware | Rhododendron cumberlandense CC-BY-NC, permission granted to NCBG | Original Image ⭷Feedback
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