Sect. II. PENTANTHERA G. Don 



Rhododendron sect. Pentanthera G. Don, Gen. Syst. III. 846 

 (1834). — Render & Wilson in Sargent, PI. Wilson. I. 549 (1913). 



Azalea Linnaeus, Spec. 150 (1753), as to species 2 to 4. — De Candolle, Prodr. 

 VII. 715 (1838), excluding species 13, 14, 16. — Britton & Brown, IU. Fl. 

 II. 558 (1897). 



Rhododendron a. Anthodendron Endlicher, Gen. 759 (1839). — Zabel in Mitt. 

 Deutsch. Dendr. Ges. XI. 28 (1902), as section. 



Theis "Salisb. in coll. 1817" ex De Candolle, Prodr. VII. 715 (1839), synonym. 



Rhododendron sect. Azalea Regel in Act. Hort. Petrov- I- 162 (1871), exclud- 

 ing species 5 and 8. 



Azalea subgen. Pentanthera K. Koch, Dendr. II. 1, 186 (1872). 



Azalea subgen. Euazalea K. Koch, Dendr. II. 1, 179 (1872), as to species 11, 12. 



Rhododendron sect. Euazalea Dippel, Handb. Laubholzk. I. 411 (1889). — 

 Koehne, Deutsch. Dendr. 458 (1893). 



Deciduous upright shrubs, rarely almost tree-like, sometimes stoloniferous, 

 with usually irregularly whorled branches; branchlets usually more or less strigose 

 or hirsute, sometimes glabrous. Winter-buds with many imbricate scales. 

 Leaves scattered. Flowers several to many from a terminal bud, the leafy shoots 

 from separate lateral buds; corolla funnel-form, subregular, the tube about as long 

 or longer than the limb; stamens 5, usually much exserted; ovary more or less 

 strigose or setose. Capsule with woody valves. 



The type species of this section is Rhododendron luteum Sweet. The section con- 

 tains besides the sixteen American species enumerated below, two species from 

 eastern Asia, R. molle Miq. and R. japonicum Suring., and one from southeastern 

 Europe and western Asia, R. luteum Sweet. In America it occupies two distinct 

 geographical areas: one on the Atlantic coast, extending from southern Quebec to 

 central Florida and west to Vermont, eastern Ohio, southeastern Missouri, 

 central Alabama, extreme eastern Oklahoma and eastern Texas; and one on the 

 Pacific coast from southern Oregon to southern California. 



From the section Rhodora this section is easily distinguished by the funnel-form 

 subregular corolla with a distinct cylindric tube longer or little shorter than the 

 lobes and by the 5 stamens; the ovary is always densely villose and strigillose, 

 with or without glands. Most species show a wide range of variation particularly 

 in the pubescence of the leaves and in the color of the flowers. The leaves vary 

 from nearly glabrous to pubescent in R. oblongifolium, R. serrulatum, R. canescens, 

 R. roseum, R. occidentale and R. atlanticum; they are always glabrous except the 

 midrib in R. nudiflorum, R. arborescens and R. prunifolium and usually so in 

 R. viscosum; they are always pubescent in R. alabamense and, though usually only 

 slightly so, in R. calendvlaceum and R. speciosum. The pubescence of the winter- 

 buds which affords a character hitherto neglected, shows less variation; they vary 

 from glabrous to finely pubescent in R. nudiflorum, R. viscosum, R. serrulatum, B. 

 atlanticum and R. occidentale; they are always glabrous in R. calendulaceum, 

 R. speciosum, R. arborescens, R. alabamense and R. prunifolium and always pu- 

 bescent in R. canescens, R. roseum and R. oblongifolium. The branchlets are in 

 most species more or less pubescent, usually villose and strigillose, but are always 



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