Rhododendron L. (incl. Azalea L.)
Rhododendron is a large genus of ca. 700-800 (or more) species, most confined to north temperate areas (some extending further south). Numerous species are cultivated as ornamentals in European gardens (more than 300 and perhaps even as much as 500 according to Cullen 1997) but only few are really common. As currently circumscribed, Rhododendron also includes the genus Azalea.
The two species treated here in detail are perhaps no pure species and part of the populations possibly represent rather complex, artificially raised hybrids.
- Leaves slightly pubescent, finely serrate, deciduous. Flowers yellow. Stamens 5 === 1. Rhododendron luteum
- Leaves glabrous, entire, leathery, and evergreen. Flowers violet-purple. Stamens 10 === 2. Rhododendron ponticum
Literature:
There is a vast literature on the genus Rhododendron. Numerous additional references are cited by Cullen l.c.
Cullen J. (1997) Rhododendron. In: Cullen J. & al. (eds.), The European Garden Flora, vol. 5. Cambridge University Press, Cambridge: 418-476.
De Koning J., Van den Broek J.W., Van de Laar H.J. & Fortgens G. (2000) Nederlandse dendrologie (13e druk). H. Veenman & zonen, Ede: 585 p.