Rhododendron sect. Rhodora

Rhodora
Rhododendron canadense
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Eudicots
(unranked):	Asterids
Order:	Ericales
Family:	Ericaceae
Genus:	Rhododendron
Subgenus:	Pentanthera
Section:	Rhodora (L.) G.Don
Species
See text

Rhodora was a section of subgenus Pentanthera in the genus Rhododendron, that has since been discontinued. It comprised two species, both deciduous shrubs native to eastern North America:

• Rhododendron canadense
• Rhododendron vaseyi

Description

The section was closely related to sect. Pentanthera, differing from it in the flower corolla having only three lobes, rather than five, the upper three lobes of sect. Pentanthera being joined into a single three-lipped lobe in sect. Rhodora.

Taxonomy

The distinct floral structure resulted in Rhodora being treated as a distinct genus at one time. Treating it as such though resulted in the remainder of the genus Rhododendron being paraphyletic. However detailed phylogenetic analysis revealed that Rhodora was not a distinct entity, but rather polyphyletic, and it was disassembled, each species being allocated to other sections. Rhododendron canadense was moved to section Pentanethera, subgenus Hymenanthes and Rhododendron vaseyi was moved to section Sciadorhodion, which then became a new section of subgenus Azaleastrum.^[1]

References

1. Goetsch, Loretta A.; Eckert, Andrew J.; Hall, Benjamin D. (July–September 2005). "The molecular systematics of Rhododendron (Ericaceae): a phylogeny based upon RPB2 gene sequences". Systematic Botany. 30 (3): 616–626. doi:10.1600/0363644054782170.

Bibliography

• Germplasm Resources Information Network: Rhododendron sect. Rhodora
• Huxley, A., ed. (1992). New RHS Dictionary of Gardening. Macmillan.
• Chamberlain DF, Hyam R, Argent G, Fairweather G, Walter KS (1996). ‘The genus Rhododendron: its classification and synonymy.’ (Royal Botanic Garden Edinburgh: Edinburgh) ISBN 1 872291 66 X
• Craven, L.A.; Goetsch, L.A.; Hall, B.D.; Brown, G.K. (2008). "Classification of the Vireya group of Rhododendron (Ericaceae)". Blumea - Biodiversity, Evolution and Biogeography of Plants. 53 (2): 435. doi:10.3767/000651908X608070.