Ericaceae-Neotropical Blueberries
James L. Luteyn and Paola Pedraza-Peñalosa
The New York Botanical Garden

RHODODENDRON

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     Rhododendron, with approximately 850 spp., is one of the largest and most complex genera in the Ericaceae.  Only one species, R. simsii, occurs as a cultivar and rarely as an escape in the neotropics.  A second species, R. arboreum Smith, has been collected twice on Jamaica, but is not native, nor has it escaped in the Neotropics. Rhododendron simsii (section Tsutsutsi, the Indian Azaleas), is endemic to China;  however, early in the 1800's it was introduced to European gardens and is now commonly cultivated throughout the world.  In the Neotropics, it is cultivated as an ornamental (often in hanging baskets) along boulevards and in gardens in scattered areas from Mexico to Bolivia.  None of the neotropical specimens have precisely the characteristics given by Wilson (1921) for wild R. simsii, however, and they are probably members of one of the Evergreen Azalea hybrid series (particularly the Belgium Indian Azaleas or the Southern Indian Azaleas) (see Clemants, 1995c).

 

RHODODENDRON Linnaeus, Sp. pl. 1: 392.  1753.  Lectotype species.  Rhododendron ferrugineum Linnaeus, see N. L. Britton, N. Amer. trees 752.  1908.

     Terrestrial or epiphytic, evergreen or deciduous, shrubs or trees or occasionally subshrubs; indumentum extremely variable including unicellular, uniseriate, multiseriate-multicellular glandular and eglandular hairs, and scales, persistant of not.  Leaves alternate to pseudoverticillate, exstipulate, petiolate or subsessile; blades simple, flat to longitudinally curled, coriaceous or chartaceous, marginally entire or rarely ciliate-serrulate.  Buds with several to many imbricate scales.  Inflorescence terminal or less commonly axillary, perulate, umbelliform or corymbose, sometimes solitary; pedicels not articulating with the calyx; bracts and bracteoles brown and deciduous.  Flowers: calyx lobes free, usually 5(-10), often somewhat reduced; corolla sympetalous, (4-)5-8(-10)-lobed, rotate to campanulate, or funnelform, sometimes tubular, usually zygomorphic, deciduous, white to yellow, pink, purple, or deep red; stamens 5-10(-20), filaments usually unequal, pubescent or glabrous; anthers unappendaged, dehiscing by an ovate terminal pore; ovary 5(-20)-locular, superior; style slender, curved; stigma capitate.  Fruit a dry septicidal capsule, usually ovoid to oblong; seeds numerous, minute, flat and more or less winged to fusiform.

Key to Neotropical Species                                                                                               Back to Top

    Rhododendron simsii

     This is a version of the taxonomic treatment of Rhododendron (Ericaceae: Rhododendroideae: Rhodoreae) by Steven E. Clemants, modified from "Ericaceae--Part II. The Superior-Ovaried Genera (Monotropoideae, Pyroloideae, Rhododendroideae, and Vaccinioideae p.p.)."  The full treatment including specimen citations may be seen in Flora Neotropica Monograph 66: 131-132 (Clemants, 1995c).  This on-line synthesis is published with permission of The New York Botanical Garden and Steven E. Clemants.

 

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