Rhododendron subg. Hymenanthes is a subgenus of the genus Rhododendron, with a widespread distribution in the temperate Northern Hemisphere. The species are evergreen shrubs and small to medium-sized trees (up to 20 m tall), with medium-sized to large leaves (very large, over 40 cm long, in a few species). The flowers are large, produced in terminal trusses of 5-40 together.
The subgenus includes two sections, Rhododendron sect. Ponticum, divided into 24 subsections and about 140 species, and (since 2005) Rhododendron sect. Pentanthera.
Cultivation This subgenus includes the majority of the larger evergreen rhododendrons widely grown as ornamental plants. Some species, notably Rhododendron ponticum, have escaped from cultivation and become invasive in some regions such as New Zealand.
Ponticum Section Ponticum (24 subsections) includes: R. subsect. Arborea (4 species) R. subsect. Argyrophylla (23 species) R. subsect. Barbata (2 species) R. subsect. Campanulata (2 species) R. subsect. Campylocarpa (4 species) R. subsect. Falconera (7 species) R. subsect. Fortunea (39 species) R. subsect. Fulgensia (2 species) R. subsect. Fulva (2 species) R. subsect. Glischra (5 species) R. subsect. Grandia (9 species) R. subsect. Griersoniana (one species, R. griersonianum) R. subsect. Irrorata (7 species) R. subsect. Lanata (6 species) R. subsect. Maculifera (6 species) R. subsect. Neriiflora (19 species) R. subsect. Parishia (3 species) R. subsect. Pontica (13 species) R. subsect. Selensia (5 species) R. subsect. Taliensia (20 species) R. subsect. Thomsonia (7 species) R. subsect. Venatora (one species, R. venator) R. subsect. Williamsiana (one species, R. williamsianum)
Arborea Rhododendron subsect. Arborea is a subsection of section Ponticum in Hymenanthes consisting of 4 species of trees native to East Asia.
Image Name Distribution Rhododendron arboreum China (Guizhou, S Xizang), Bhutan, India, Kashmir, Nepal, Sikkim, Sri Lanka, Thailand, VietnamRhododendron delavayi China (Guangxi, Guizhou, Sichuan, Xizang, Yunnan), Bhutan, India, Myanmar, Thailand, Vietnam Rhododendron lanigerum China (Xizang), IndiaRhododendron niveum China (Xizang), Bhutan, India (Sikkim) Argyrophylla Rhododendron subsect. Argyrophylla is a subsection of section Ponticum in Hymenanthes consisting of 23 species of shrubss native to East Asia. This section is distinguished by its silvery white, pale yellow or yellowish-brown hairs on the abaxial leaf surface.
Image Name Distribution Rhododendron adenopodum China ( Chongqing, Hubei) Rhododendron argyrophyllum China (Guizhou, Sichuan, Yunnan) Rhododendron brevipetiolatum China (Sichuan)Rhododendron coryanum China ( Xizang, Yunnan) Rhododendron denudatum China (Guizhou, Sichuan, Yunnan) Rhododendron ebianense China (Sichuan ) Rhododendron eriobotryoides China (Guizhou)Rhododendron fangchengense China (Guizhou) Rhododendron farinosum China (Yunnan) Rhododendron floribundum China (Guizhou, Sichuan, Yunnan.) Rhododendron formosanum Taiwan Rhododendron haofui China (Guangxi, Guizhou, Hunan, Jiangxi, Yunnan)Rhododendron hunnewellianum China (Gansu, Sichuan) Rhododendron hypoglaucum China (Chongqing, Hubei, Shaanxi, Sichuan.) Rhododendron insigne China (Sichuan.)Rhododendron longipes China (Chongqing, Guizhou, Sichuan, Yunnan.) Rhododendron oblancifolium China (Guizhou)Rhododendron pingianum China (Sichuan)Rhododendron pudiense China (Guizhou) Rhododendron ririei China (Sichuan) Rhododendron shimenense China (Hunan) Rhododendron simiarum China (Anhui, Fujian, Guangdong, Guangxi, Guizhou, Hainan, Hunan, Jiangxi, Zhejiang) Rhododendron thayerianum China (Sichuan) Barbata Rhododendron subsect. Barbata is a subsection of section Ponticum in Hymenanthes consisting of 5 species of small trees native to East Asia.
Image Name Distribution Rhododendron argipeplum China (Xizang), Bhutan, India (Sikkim) Rhododendron barbatum China (Xizang), Bhutan, India (Sikkim), Nepal Rhododendron erosum China (Xizang), Arunachal Pradesh Rhododendron exasperatum China (Xizang), India, Myanmar Rhododendron succothii Bhutan, India (W Arunachal Pradesh) Campanulata Rhododendron subsect. Campanulata is a subsection of section Ponticum in Hymenanthes consisting of 2 species of shrubs native to East Asia.
Image Name Distribution Rhododendron campanulatum China (Xizang), Bhutan, India (Kashmir, Sikkim, Himachal Pradesh), Nepal Rhododendron gannanense China (Gansu)
Campylocarpa Rhododendron subsect. Campylocarpa is a subsection of section Ponticum in Hymenanthes consisting of 6 species of shrubs with campanulate shaped flowers native to East Asia. Image Name DistributionRhododendron callimorphum China (Yunnan), MyanmarRhododendron campylocarpum China (Xizang, Yunnan) Bhutan, India (Sikkim), Myanmar, Nepal, Rhododendron henanense China (Henan)Rhododendron longicalyx China (Sichuan)Rhododendron souliei China (Sichuan, Xizang)Rhododendron wardii China (Sichuan, Xizang, Yunnan)
Falconera Rhododendron subsect. Falconera is a subsection of section Ponticum in Hymenanthes consisting of 14 species of shrubs and trees with thick leaves that have yellow veins and red brown hairs on the underside that are native to East Asia. Image Name DistributionRhododendron arizelum China (Xizang, Yunnan), MyanmarRhododendron basilicum China (Yunnan), MyanmarRhododendron coriaceum China (Xizang, Yunnan)Rhododendron falconeri Nepal, India (Sikkim, Arunachal Pradesh, West Bengal), BhutanRhododendron fictolacteum China (Sichuan, Xizang, Yunnan), MyanmarRhododendron galactinum China (Sichuan)Rhododendron hodgsonii China (Xizang), Bhutan, India (Sikkim), NepalRhododendron mechukae India (Arunachal Pradesh)Rhododendron preptum China (Yunnan), MyanmarRhododendron rex China (Sichuan, Xizang, Yunnan) MyanmarRhododendron rothschildii China (Yunnan)Rhododendron semnoides China (Xizang, Yunnan)Rhododendron sinofalconeri China (Yunnan), VietnamRhododendron titapuriense India (Arunachal Pradesh)
Fortunea Rhododendron subsect. Fortunea is a subsection of section Ponticum in Hymenanthes consisting of 37 species of shrubs or trees native to East Asia.
Image Name Distribution Rhododendron asterochnoum China (Sichuan)Rhododendron auriculatum China (Shaanxi, Guizhou) Rhododendron bailiense China (Guizhou)Rhododendron calophytum China (Chongqing, Gansu, Guizhou, Hubei, Shaanxi, Sichuan, Yunnan) Rhododendron chihsinianum China (Guangxi) Rhododendron davidii China (Sichuan, Yunnan)Rhododendron decorum China (Guizhou, SW Sichuan, SE Xizang, Yunnan), MyanmarRhododendron discolor China (Anhui, Chongqing, Guangxi, Guizhou, Hubei, Hunan, Jiangxi, Shaanxi, Sichuan, Yunnan, Zhejiang) Rhododendron faithiae China (Guangdong, Guangxi)Rhododendron fortunei China (Anhui, Fujian, Guangdong, Guangxi, Guizhou, Henan, Hubei, Hunan, Jiangxi, Shaanxi, Sichuan, Yunnan, Zhejiang)Rhododendron glanduliferum China (Yunnan)Rhododendron griffithianum China (Xizang), Bhutan, N India, E Nepal, Sikkim Rhododendron guihainianum China (Guangxi)Rhododendron hemsleyanum China (Sichuan) Rhododendron huangpingense China (Guizhou) Rhododendron huanum China (Chongqing, Guizhou, Sichuan, Yunnan) Rhododendron jinchangense China (Yunnan) Rhododendron jingangshanicum China (Jiangxi) Rhododendron jiulongshanense China (Guizhou) Rhododendron leigongshanense China (Guizhou) Rhododendron liboense China (Guizhou) Rhododendron magniflorum China (Guizhou) Rhododendron maoerense China (Guangxi) Rhododendron miyiense China (Sichuan) Rhododendron nymphaeoides China (Sichuan)Rhododendron orbiculare China (Guangxi, Sichuan)Rhododendron oreodoxa China (Gansu, Hubei, Shaanxi, Sichuan, Xizang) Rhododendron platypodum China (Chongqing) Rhododendron praeteritum China (Gansu, Hubei, Hunan, Qinghai)Rhododendron praevernum China (Guizhou, Hubei, Shaanxi, Sichuan, Yunnan) Rhododendron qiaojiaense China (Yunnan)Rhododendron serotinum China (Yunnan), VietnamRhododendron sutchuenense China (Chongqing, Gansu, Guangxi, Guizhou, Hubei, Hunan, Shaanxi)Rhododendron vernicosum China (Sichuan, Xizang, Yunnan) Rhododendron verruciferum China (Sichuan) Rhododendron wolongense China (Sichuan) Rhododendron xiaoxidongense China (Jiangxi) Fulgensia Rhododendron subsect. Fulgensia is a subsection of section Ponticum in Hymenanthes consisting of 3 species of shrubs with glossy leaves that have dark brown hairs on the underside native to East Asia.
Image Name Distribution Rhododendron fulgens China (Xizang), Bhutan, India (Sikkim), Nepal Rhododendron miniatum China (Xizang) Rhododendron rawatii India (Uttarakhand)
Fulva Rhododendron subsect. Fulva is a subsection of section Ponticum in Hymenanthes comprising 2 species of shrubs native to East Asia.
Image Name Distribution Rhododendron fulvum China (Sichuan, Xizang, W Yunnan), MyanmarRhododendron uvariifolium China (Sichuan, Xizang, Yunnan)
Glischrum Rhododendron subsect. Glischrum is a subsection of section Ponticum in Hymenanthes comprising 9 species of shrubs native to East Asia.
Image Name Distribution Rhododendron adenosum China (Sichuan) Rhododendron crinigerum China (Sichuan, Xizang, Yunnan) Rhododendron diphrocalyx China (Yunnan) Rhododendron glischroides MyanmarRhododendron glischrum China (Xizang, Yunnan) India, Myanmar Rhododendron habrotrichum China (Yunnan), MyanmarRhododendron recurvoides Myanmar Rhododendron spilotum Myanmar Rhododendron vesiculiferum China (Xizang, Yunnan), Myanmar
Grandia Rhododendron subsect. Grandia is a subsection of section Ponticum in Hymenanthes that comprises 15 species of trees with large leaf blades covered with trichomes native to East Asia.
Image Name Distribution Rhododendron balangense China (Sichuan)Rhododendron grande China(Xizang), Bhutan, India (Arunachal Pradesh, Sikkim), NepalRhododendron kesangiae BhutanRhododendron macabeanum China (Xizang), Myanmar Rhododendron magnificum China (Xizang) Rhododendron montroseanum China (Xizang) Rhododendron oreogenum China (Xizang)Rhododendron praestans China (Xizang, Yunnan)Rhododendron protistum China (Xizang, Yunnan), Myanmar Rhododendron pudorosum China (Xizang) Rhododendron sidereum China (Yunnan), MyanmarRhododendron sinogrande China (Xizang, Yunnan), Myanmar Rhododendron suoilenhense Vietnam Rhododendron watsonii China (Gansu, Sichuan) Rhododendron wattii India (Assam) Griersoniana Rhododendron subsect. Griersoniana is a subsection of section Ponticum in Hymenanthes that contains a single species of shrub.
Image Name Distribution Rhododendron griersonianum China (Yunnan), Myanmar
Maculifera Rhododendron subsect. Maculifera is a subsection of section Ponticum in Hymenanthes that contains 15 species of shrubs or small trees with tomentose stems and rough bark.
Image Name Distribution Rhododendron anwheiense China (Anhui)Rhododendron longesquamatum China (Sichuan)Rhododendron maculiferum China ( Anhui, Gansu, Guangxi, Guizhou, Hubei, Hunan, Jiangxi, Shaanxi, Sichuan, Zhejiang)Rhododendron morii Taiwan Rhododendron ochraceum China (Sichuan, Yunnan) Rhododendron pachyphyllum China (Guangxi, Hunan)Rhododendron pachysanthum Taiwan Rhododendron pachytrichum China (Sichuan, Shaanxi) Rhododendron pilostylum China (Yunnan) Rhododendron polytrichum China (Guangxi, Hunan)Rhododendron pseudochrysanthum Taiwan Rhododendron sikangense China (Sichuan)Rhododendron strigillosum China (Sichuan, Yunnan) Rhododendron subroseum China (Guizhou)Rhododendron ziyuanense China (Guangxi)
Lanata Rhododendron subsect. Lanata contains 6 species of small trees found in east asia Image Name Distribution Rhododendron circinnatum China (Xizang) Rhododendron lanatoides China (Xizang) Rhododendron lanatum China (Xizang), Bhutan, India (Sikkim) Rhododendron luciferum China (Xizang) Rhododendron poluninii Bhutan Rhododendron tsariense China (Xizang), Bhutan, India Parishia Rhododendron subsect. Parishia is a subsection of section Ponticum in Hymenanthes that contains 8 species of small trees found in east asia.