Rhododendron species in Sikkim– 48 species and subspecies shown as comparative images herein.


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Pictorial guide to Rhododendrons of Sakteng Wildlife Sanctuary (page 7)- June 2018- Sonam Wangyel, Keesang Dorjee, Jangchu Wangdi & Thinley Wangdi


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Rhododendron delavayi Franch. (syn: Rhododendron arboreum subsp. delavayi (Franch.) D.F.Chamb.) (E. Himalaya to S. Central China (and NW. Guangxi) to Indo-China: Assam, China South-Central, China Southeast, East Himalaya, Myanmar, Thailand, Tibet, Vietnam as per POWO)
 


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Rhododendron macabeanum Watt ex I. B. Balf. (NE-India (Manipur) as per CoL)


Rhododendron maddenii Hook. f.
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Rhododendron megeratum I. B. Balf & Forrest (Arunachal Pradesh to China (NW. Yunnan): China South-Central, East Himalaya, Myanmar, Tibet as per POWO)

 


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Rhododendron veitchianum Hook. (E. Assam to Indo-China: Assam, Laos, Myanmar, Thailand, Vietnam as per POWO)

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Rhododendron virgatum Hook. f.

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An important document of species of Rhododendron L. occurring in India is Bhattacharyya & Sanjappa (2014). It mentions 102 species in Indian territories. Colour images of 37 species and diagrams of 33 species are also given in this account:

R. adenosum (Covan & Davidian) Davidian
R. aeruginosum Hook.f.
R. anthopogon D. Don 
R. arboreum Sm.
R. argipeplum Balf.f. & R.E.Cooper
R. arizelum Balf.f. & Forrest
R. arunachalense D.F.Chamb. & Rae
R. baileyi Balf.f. 
R. barbatum Wall. ex G. Don 
R. beanianum Cowan 
R. boothii Nutt. 
R. callimorphum Balf.f. & W.W.Sm.
R. calostrotum Balf. f. & Kingdon-Ward
R. camelliiflorum Hook. f. 
R. campanulatum D. Don
R. campylocarpum Hook.f. 
R. campylogynum Franch. 
R. cephalanthum Franch. 
R. cerasinum Tagg 
R. chamaethomsonii (Tagg) Cowan & Davidian
R. charitopes Balf.f. & Farrer
R. ciliatum Hook.f. 
R. ciliicalyx Franch.
R. cinnabarinum Hook.f. 
R. collettianum Aitch. & Hensl.
R. concinnoides Hutch. & Kingdon-Ward
R. crassum Franch.
R. crinigerum Franch. 
R. dalhousiae Hook. f.
R. decipiens Lacaita
R. dekatanum Cowan 
R. dendricola Hutch. 
R. eclecteum Balf.f. & Forrest
R. edgeworthii Hook.f. 
R. elliottii Watt ex Brandis
R. exasperatum Tagg
R. falconeri Hook. f. 
R. faucium D.F.Chamb.
R. formosum Wall. 
R. forrestii Balf.f. ex Diels
R. fulgens Hook. f.  
R. glaucophyllum Rehder 
R. glischrum Balf.f. & W.W.Sm.
R. grande Wight
R. griffithianum Wight 
R. hodgsonii Hook. f. 
R. hookeri Nutt. 
R. johnstoneanum (Brandis) Watt ex Hutch. 
R. kasoense Hutch. & Kingdon-Ward 
R. kendrickii Nutt. 
R. keysii Nutt. 
R. lanatum Hook. f. 
R. lanigerum Tagg 
R. lepidotum Wall. ex D. Don 
R. leptocarpum Nutt.
R. lindleyi T. Moore
R. lohitense D.Bhattach.
R. macabeanum G.Watt ex Balf. f.
R. maddenii Hook. f.
R. mechukae A.A.Mao & A.Paul
R. megacalyx Balf. f. & Kingdon-Ward
R. megeratum Balf. f. & Forrest
R. mekongense Franch.
R. moulmainense Hook.
R. nayarii G.D.Pal
R. neriiflorum Franch.
R. nivale Hook.f.
R. niveum Hook.f.
R. nuttallii T.J.Booth ex Nutt.
R. pangeanum A.A.Mao & M.Bhaumik
R. papillatum Balf. f. & R.E.Copper
R. pemakoense Kingdon-Ward
R. pendulum Hook. f.
R. pocophorum Balf. f. ex Tagg
R. protistum Balf.f. & Forrest
R. pruniflorum Hutch. & Kingdon-Ward
R. pudorosum Cowan
R. pumilum Hook. f.
R. rawatii I.D.Rai, & B.S.Adhikari
R. sanguineum Franch.
R. santapaui Sastry, S.K.Kataki, Peter Cox, Patricia Cox & P.Hutch.
R. setosum D. Don
R. sidereum Balf. f.
R. sikkimense Pradhan & Lachungpa
R. sinogrande Balf. f. & W.W.Sm.
R. stewartianum Diels
R. subansiriense D. F. Chamb. & P.A.Cox 
R. succothii Davidian
R. taggianum Hutch.
R. tanastylum Balf. f. & Kingdon-Ward
R. tephropeplum Balf. f. & Farrer
R. thomsonii Hook. f.
R. triflorum Hook. f.
R. trilectorum Cowan
R. tsariense Cowan
R. tubiforme (Cowan & Davidian) Davidian
R. vaccinioides Hook. f.
R. virgatum Hook. f.
R. walongense Kingdon-Ward
R. wattii Cowan
R. wightii Hook. f.
R. xanthostephanum Merr.

Reference: Bhattacharyya, D. and Sanjappa, M. 2014. Rhododendron L. In: Sanjappa, M. & Sastry, A.R.K. (eds.) Fascicles
of Flora of India Fascicle 25 Ericaceae
. Botanical Survey of India, Kolkata. pp. 9-157, 451-452


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The genus Rhododendron in north-east India by Ashiho A. Mao- Botanica Orientalis – Journal of Plant Science (2010) 7: 26–34 –
Abstract– The genus Rhododendron belongs to the family Ericaceae and was described by Carl Linnaeus in 1737 in Genera Plantarum. Joseph Hooker’s visit to Sikkim Himalaya between 1848 and 1850 unfold the rhododendron world of this area. Within the brief span that he travelled in Sikkim, he gathered and described 34 new species and details of 43 species including varieties from the Indian region in his monograph entitled ‘Rhododendron of Sikkim Himalaya’. Since then many workers had added to the list, and currently about 121 taxa have been recorded from India, out of which 117 (98%) taxa are distributed in north-east India. The paper presents the distribution of the genus Rhododendron in north-east India and world based on literature, field studies and examination of herbarium specimens. It also discussed the status of the genus in natural habitat in recent years and the need for conservation.
List of species as per this: (*Report based on Cox (2004, 2006), **Poorly described species, *** Doubtful occurrence)
Rhododendron anthopogon D. Don subsp. anthopogon- Sikkim, Arunachal Pradesh Bhutan, China
Rhododendron arboreum Smith subsp. arboreum- Sikkim Bhutan, Nepal
Rhododendron arboreum Smith subsp. cinnamomeum (Lindley) Tagg var. cinnamomeum- Sikkim, Arunachal Pradesh Nepal
Rhododendron arboreum Smith subsp. cinnamomeum (Lindley) Tagg var. roseum Lindley- Sikkim, Arunachal Pradesh Bhutan, Nepal and China
Rhododendron arboreum Smith subsp. delavayi (Franchet) Chamberlain var. delavayi- Manipur, Meghalaya, Mizoram, Nagaland, Arunachal Pradesh Myanmar, Thailand, China
Rhododendron arboreum Smith subsp. delavayi (Franchet) Chamberlain var. peramoenum (Balf.f. & Forrest)
Chamberlain- Arunachal Pradesh China
Rhododendron argipeplum Balf.f. & Cooper- Sikkim and Arunachal Pradesh Bhutan, China
Rhododendron arizelum Balf.f. & Forrest- Arunachal Pradesh China
Rhododendron arunachalense Chamberlain & Rae- Arunachal Pradesh (Endemic) ‐
Rhododendron baileyi I.B. Balfour- Sikkim Bhutan, China
Rhododendron barbatum Wall. ex G. Don- Sikkim, Arunachal Pradesh Bhutan, Nepal and China
Rhododendron beanianum Cowan- Arunachal Pradesh Myanmar
Rhododendron bhutanense D.G. Long & Bowes Lyon- Arunachal Pradesh Bhutan and China
**Rhododendron blumei Nuttall,- Arunachal Pradesh China
Rhododendron boothii Nuttall- Arunachal Pradesh China
Rhododendron callimorphum Balf.f. & W.W. Smith var. callimorphum- Arunachal Pradesh China
Rhododendron calostrotum Balf.f. & Kingdon‐Ward subsp. riparium (Kingdon‐Ward) Cullen- Arunachal Pradesh Myanmar and China
Rhododendron camelliiflorum Hook.f.- Sikkim, Arunachal Pradesh Bhutan and Nepal
Rhododendron campanulatum D.Don subsp. aeruginosum (Hook.f.) Chamberlain- Sikkim, Arunachal Pradesh Bhutan
Rhododendron campanulatum D.Don subsp. campanulatum- Sikkim, Arunachal Pradesh Bhutan and Nepal
Rhododendron campylocarpum Hook.f. subsp. campylocarpum- Sikkim, Arunachal Pradesh Bhutan, Nepal and China
Rhododendron campylogynum Franchet- Arunachal Pradesh China and Myanmar
Rhododendron cephalanthum Franchet subsp. cephalanthum- Arunachal Pradesh China and Myanmar
Rhododendron cerasinum Tagg Arunachal Pradesh China (S.E. Xizang), Myanmar (N.E.)
Rhododendron chamaethomsonii (Tagg & Forrest) Cowan & Davidian var. chamaethauma (Tagg) Cowan & Davidian- Arunachal Pradesh China
*Rhododendron charitopes Balf.f. & Farrer subsp. tsangponse (Kingdon‐Ward) Cullen- Arunachal Pradesh China
Rhododendron ciliatum Hook.f.- Sikkim, Arunachal Pradesh Bhutan, Nepal and China
Rhododendron cinnabarinum Hook.f. subsp. cinnabarinum- Sikkim, Arunachal Pradesh Bhutan, Nepal and China
Rhododendron cinnabarinum Hook.f. subsp. xanthocodon (Hutchinson) Cullen- Arunachal Pradesh Bhutan and China
Rhododendron concinnoides Hutchinson & Kingdon Ward- Arunachal Pradesh (Endemic) ‐
Rhododendron coxianum Davidian- Arunachal Pradesh (Endemic) ‐
Rhododendron crinigerum Franchet var. crinigerum- Arunachal Pradesh Myanmar and China
Rhododendron dalhousiae Hook.f. var. dalhousiae- Sikkim, Arunachal Pradesh Bhutan, Nepal and China
Rhododendron dalhousiae Hook.f. var. rhabdotum (Balf.f. & R.E. Cooper) Cullen- Arunachal Pradesh Bhutan and China
Rhododendron dalhousiae Hook.f. var. tashii- U.C. Pradhan Sikkim (Endemic) ‐
Rhododendron dendricola Hutchinson- Arunachal Pradessh China and Myanmar
Rhododendron electeum Balf.f. & Forrest var. electeum- Arunachal Pradesh China and Myanmar
Rhododendron edgeworthii Hook.f.- Sikkim, Arunachal Pradesh Bhutan, Myanmar and China
Rhododendron elliottii Watt- Manipur and Nagaland (Endemic) ‐

Rhododendron eudoxum Cowan var. eudoxum- Arunachal Pradesh China
Rhododendron exasperatum Tagg- Arunachal Pradesh Myanmar and China
Rhododendron falconeri Hook.f. subsp. eximium (Nuttall) Chamberlain- Arunachal Pradesh Bhutan
Rhododendron falconeri Hook.f. subsp. falconeri- Sikkim, Arunachal Pradesh Bhutan and Nepal
*Rhododendron faucium D.F. Chamberlain- Arunachal Pradesh China
Rhododendron flinckii Davidian- Arunachal Pradesh Bhutan
Rhododendron formosum Wallich var. formosum- Meghalaya (Endemic) ‐
Rhododendron formosum Wallich var. inaequale (Hutchinson) Cullen- Meghalaya, Manipur, Nagaland, Mizoram, Arunachal Pradesh (endemic) ‐
Rhododendron forestii Balf.f. ex Diels subsp. forestii- Arunachal Pradesh China and Myanmar
*Rhododendron fragariflorum Kindon‐Ward- Arunachal Pradesh Bhutan and China
Rhododendron fulgens Hook.f.- Sikkim, Arunachal Pradesh Nepal, Bhutan and China
Rhododendron fulvum Balf.f. & W.W. Smith- Arunachal Pradesh Myanmar and China
Rhododendron glaucophyllum Rehder var. glaucophyllum- Sikkim Nepal, Bhutan, China
Rhododendron glaucophyllum Rehder var. tubiforme Cowan & Davidian- Arunachal Pradesh Bhutan and China
Rhododendron glischrum Balf.f. & W.W. Smith subsp. rude (tag & Forrest) Chamberlain- Arunachal Pradesh China
Rhododendron grande Wight- Sikkim, Arunachal Pradesh Nepal, Bhutan and China
Rhododendron griffithianum Wight- Sikkim, Arunachal Pradesh Nepal and Bhutan
*Rhododendron haematodes subsp. chaetomallum (I.B.Balfour & Forrest) D.F. Chamberlain- Arunachal Pradesh China
Rhododendron hodgsonii Hook.f.- Sikkim, Arunachal Pradesh Bhutan, Nepal and China
Rhododendron hookerii Nuttall- Arunachal Pradesh (Endemic) ‐
Rhododendron hylaeum Balf.f. & Farrer- Arunachal Pradesh China and Myanmar
Rhododendron imperator Kingdon‐Ward- Arunachal Pradesh Myanmar and China
Rhododendron johnstoneanum (Watt ex) Hutchinson- Manipur, Mizoram and Nagaland (Endemic)‐
Rhododendron kasoense Hutchinson & Kingdon‐Ward- Arunachal Pradesh China
Rhododendron kendrickii Nuttall- Arunachal Pradesh Bhutan and China
Rhododendron kesangiae D.G. Long & Rushforth var. Kesangiae- Arunachal Pradesh Bhutan
Rhododendron keysii Nuttall- Sikkim, Arunachal Pradesh Bhutan and China
*Rhododendron lacteum Franchet- Arunachal Pradesh China
Rhododendron lanatum Hook.f.- Sikkim, Arunachal Pradesh Bhutan and China
Rhododendron lanigerum Tagg- Arunachal Pradesh China
Rhododendron lepidotum Wallich ex G. Don- Sikkim, Arunachal Pradesh, Manipur and Nagaland
Nepal, Bhutan, Myanmar and China
Rhododendron leptocarpum Nuttall ex C.B. Clarke- Arunachal Pradesh, Sikkim Bhutan, Myanmar and
China
Rhododendron lindleyi T. Moore- Sikkim, Arunachal Pradesh Nepal Bhutan and China
Rhododendron ludlowii Cowan- Arunachal Pradesh China
Rhododendron macabeanum Watt ex Balf.f- Manipur and Nagaland (Endemic) ‐
Rhododendron maddenii Hook.f. subsp. crassum (Franchet) Cullen- Arunachal Pradesh, Manipur, Nagaland Myanmar, China and Vietnam
Rhododendron maddenii Hook f. subsp. maddenii- Sikkim, Arunachal Pradesh Bhutan
Rhododendron megacalyx Balf.f & Kingdon‐Ward- Arunachal Pradesh Myanmar and China
Rhododendron megeratum Balf.f. & Forrest Arunachal Pradesh Bhutan, Myanmar and China
Rhododendron mekongense Franchet var. rubrolineatum (Balf.f. & Forrest) Cullen- Arunachal Pradesh China
Rhododendron moulmainense Hook.f.- Arunachal Pradesh China, Myanmar, Taiwan, Japan, S. Indo‐China to W.Malayasia
Rhododendron nayarii G.D. Pal- Arunachal Pradesh (Endemic) ‐
Rhododendron neriiflorum Franchet subsp. phaedropum (Balf.f. & Farrer) Tagg- Arunachal Pradesh Bhutan, Myanmar and China
Rhododendron nivale Hook.f. subsp. nivale- Sikkim, Arunachal Pradesh Nepal, Bhutan and China
Rhododendron niveum Hook.f.- Sikkim, Arunachal Pradesh Bhutan
Rhododendron nuttallii Booth- Arunachal Pradesh Bhutan and China
Rhododendron papillatum Balf.f. & Cooper- Arunachal Pradesh Bhutan
Rhododendron pendulum Hook.f.- Sikkim, Arunachal Pradesh Bhutan, Nepal and China
*Rhododendron piercei Davidian- Arunachal Pradesh China
Rhododendron pocophorum (Balf.f ex) Tagg var. pocophorum- Arunachal Pradesh China
Rhododendron prostitum Balf.f. & Forrest var. prostitum- Arunachal Pradesh Myanmar and China
Rhododendron pruniflorum Hutchinson- Arunachal Pradesh Myanmar and China
Rhododendron pumilum Hook.f.- Sikkim, Arunachal Pradesh Nepal, Bhutan, Myanmar and China
Rhododendron santapaui A.R.K. Sastry, S.K. Kataki, P.A. & E.P. Cox- Arunachal Pradesh (Endemic) ‐
Rhododendron setosum D.Don- Sikkim, Arunachal Pradesh Bhutan and China
Rhododendron sherrifii Cowan- Arunachal Pradesh China
Rhododendron sidereum Balf.f.- Arunachal Pradesh Myanmar and China
Rhododendron sikkimense U.C. Pradhan- Sikkim and Arunachal Pradesh (Endemic) ‐
Rhododendron sinogrande Balf.f. & W.W. Smith- Arunachal Pradesh Myanmar and China
Rhododendron subansiriense Chamberlain & Cox- Arunachal Pradesh (Endemic) ‐
Rhododendron succothii Davidian- Arunachal Pradesh Bhutan
Rhododendron taggianum Hutchinson- Arunachal Pradesh Myanmar and china
Rhododendron tanastylum Balf.f. & Kingdon‐Ward var. tanastylum- Arunachal Pradesh Myanmar and China
Rhododendron tephropeplum Balf.f. & Farrer- Arunachal Pradesh Myanmar and China
Rhododendron thomsosnii Hook.f. subsp. thomsonii- Arunachal Pradesh, Sikkim Nepal, Bhutan and China
Rhododendron triflorum Hook.f. var. bauhiniiflorum (Watt ex Hutchinson) Cullen- Manipur and Nagaland (Endemic) ‐
Rhododendron triflorum Hook.f. var. triflorum- Sikkim, Arunachal Pradesh Nepal, Bhutan, Myanmar
and China
Rhododendron trilectorum Cowan- Arunachal Pradesh China
Rhododendron tsariense Cowan- Arunachal Pradesh Bhutan and China
Rhododendron uvarifolium Diels var. uvarifolium- Arunachal Pradesh China
***Rhododendron vietchianum Hooker Mizoram Myanmar, Laos and Thailand
Rhododendron vaccinioides Hook.f.- Manipur, Nagaland, Arunachal Pradesh, Sikkim Nepal, Bhutan, China and Myanmar
Rhododendron virgatum Hook.f. subsp. virgatum- Sikkim, Arunachal Pradesh Bhutan and China
Rhododendron wallichii Hook.f.- Sikkim and Arunachal Pradesh Nepal, Bhutan and China
Rhododendron walongense Kingdon‐Ward- Arunachal Pradesh China
Rhododendron wattii Cowan- Manipur and Nagaland (Endemic) ‐
Rhododendron wightii Hook.f.- Sikkim and Arunachal Pradesh Nepal, Bhutan and China
Rhododendron xanthostephanum Merrill- Arunachal Pradesh Myanmar and China


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Rhododendrons in Indian Himalayan Region: Diversity and Conservation by K. Chandra Sekar, Sunil Kumar Srivastava- American Journal of Plant Sciences, 2010, 1, 131-137
ABSTRACT– The genus Rhododendron of Indian Himalayan Region (IHR) has been enumerated in the present paper. A total of 87 species, 12 subspecies and 8 varieties of Rhododendrons recorded in IHR, among these 6 species and one subspecies are reported from Western Himalaya. The maximum concentration of 86% observed in Arunachal Pradesh (75 species). The species of Rhododendrons exhibit significant diversity in habit and broad range of distribution from the altitude of 800-6000 m. and the best range is observed in 3001-3500 m altitudes. In analysis revealed 20 taxa are endemic, 30 are rare, 24 are threatened / endangered, 3 are vulnerable and 47 taxa have to be assessed. The major threats to rhododendrons are deforestation and unsustainable extraction for firewood and incense by local people has been discussed.
List of species as per this:
Rhododendron anthopogon D. Don
R. anthopogon D. Don subsp. hypenanthum (Balf. f.) J. Cullen
R. arboreum Sm.
R. arboreum Sm. subsp. cinnamomeum (Wall. ex G. Don) Tagg
R. arboreum Sm. var. roseum Lindl.
R. arboreum Sm. subsp. delavayi (Franch.) D. F. Chamb.
R. arboreum var. peramoenum (Balf. f. & Forrest) D.F. Chamb.
R. assamicum Kingdon-Ward
R. baileyi Balf. f.
R. barbatum G. Don
R. beanianum Cowan
R. boothii Nutt.
R. bulu Hutch.
R. calostrotum Balf. f. & Kingdon-Ward subsp. riparium (Kingdon-Ward) J. Cullen
R. camelliaeflorum Hook. f.
R. campanulatum D. Don
R. campanulatum D. Don subsp. aeruginosum (Hook. f.) D. F. Chamb.
R. campanulatum D. Don var. wallichii Hook. f.
R. campylocarpum Hook. f.
R. campylogynum Franch.
R. candelabrum Hook. f.
R. cephalanthum Franch.
R. cerasinum Tagg
R. chamaethomsonii (Tagg) Cowan & Davidian
R. ciliatum Hook. f.
R. cinnabarinum Hook. f.
R. cinnabarinum Hook. f. subsp. xanthocodon (Hutch.) J. Cullen
R. concinnoides Hutch. & Kingdon-Ward
R. coxianum Davidian
R. crinigerum Franch.
R. dalhousiae Hook. f.
R. dalhousiae Hook. f. var. rhabdotum (Balf. f. & Cooper) J. Cullen
R. decipiens Lacait.
R. dendricola Hutch.
R. edgeworthii Hook. f.
R. elliottii Watt
R. eudoxum Balf. f. & Forrest
R. eudoxum Balf. f. & Forrest subsp. tamenium (Balf. f. & Forrest) Tagg
R. exasperatum
R. falconeri Hook. f.
R. falconeri Hook. f. subsp. eximium (Nattau) D. F. Chamb.
R. formosum Kingdon-Ward
R. formosum Wall. var. inaequale (Hutch.) J. Cullen
R. fulgens Hook. f.
R. fulvum Balf. f. & W. W. Smith
R. glaucophyllum Rehder
R. glaucophyllum Rehder var. tubiforme Cowan & Davidian
R. grande Wight
R. griffithianum Wight
R. hodgsonii Hook. f.
R. hookeri Nutt.
R. imberbe Hutch.
R. johnstoneanum Watt ex Hutch.
R. kasoense Hutch. & Kingdon-Ward
R. kendrickii Nutt.
R. keysii Nutt.
R. lanatum Hook. f.
R. lanigerum Tagg
R. lepidotum Wall. ex D. Don
R. leptocarpum Nutt.
R. lindleyi T. Moore
R. macabeanum Watt ex Balf. f.
R. maddenii Hook. f. subsp. crassum (Franch.) J. Cullen
R. maddenii Hook. f.
R. megacalyx Balf. f. & Kingdon-Ward
R. megeratum Balf. f. & Forrest
R. mekongense Franch. var. rubrolineatum (Balf. f. & Forr.) J. Cullen
R. nayarii G.D. Pal
R. neriiflorum Franch. subsp. phaedropum (Balf. f. & Farrer) Tagg
R. nivale Hook. f.
R. niveum Hook. f.
R. nuttallii Booth ex Nutt.
R. obtusum Hort. ex Wats
R. papillatum Balf. f. & Copper
R. pemakoense Kingdon-Ward
R. pendulum Hook. f.
R. pocophorum Balf. f. ex Tagg
R. pruniflorum Hutch. & Kingdon-Ward
R. pumilum Hook. f.
R. rex Levl. subsp. Arizelum (Balf. f. & Forr.) D. F. Chamb.
R. santapaui Sastry, Kataki, P. Cox, Patricia Cox & P. Hutch.
R. setosum D. Don
R. sidereum Balf. f.
R. sikkimense U. C. Pradhan & S. T. Lachungpa
R. sinogrande Balf. f.
R. smithii Nutt.
R. stenaulum Balf. f. & W. W. Smith
R. stewartianum Diels
R. subansiriense D. F. Chamb. & Cox
R. succothii Davidian
R. taggianum Hutch.
R. tanastylum Balf. f. & Kingdon-Ward
R. tephropeplum Balf. f. & Farrer
R. thomsonii Hook. f.
R. triflorum Hook. f.
R. triflorum Hook var. bauhiniiflorum (Watt ex Hutch.) J. Cullen
R. tsariense Cowan
R. uvarifolium Diels
R. vaccinioides Hook. f.
R. virgatum Hook. f.
R. virgatum Hook. f. subsp. oleifolium (Franchet) J. Cullen
R. veitchianum Hook.
R. wallichii Hook. f.
R. walongense Kingdon-Ward
R. wattii Cowan
R. wightii Hook. f.
R. xanthostephanum Merrill

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Rhododendron Species and Their Uses with Special Reference to Himalayas (2011) by Debjyoti Bhattacharyya:

R. anthopogon D. Don,
Rhododendron arboreum Sm.,
R. barbatum Wall. ex G. Don,
R. campanulatum D. Don,
R. cinnabarinum Hook. f.,
R. falconeri Hook. f.,
R. fulgens Hook.f.,
R. hodgsonii Hook. f.,
R. lepidotum Wall. ex G. Don,
R. niveum Hook. f.,
R. thomsonii Hook. f.

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Rhododendron Species in the Indian Eastern Himalayas: New Approaches to Understanding Rare Plant Species Distributions by Shaily Menon*, Mohamed Latif Khan, Ashish Paul, and A. Townsend Peterson- JOURNAL AMERICAN RHODODENDRON SOCIETY- SPRING 2012

Abstract : Rhododendron species serve an important ecological and economic role in the
mountains of the Eastern Himalayas. Recent changes in this once-pristine landscape have resulted in the classification of many Rhododendron species as threatened or endangered. This study used field surveys and ecological niche modeling to expand existing knowledge about Rhododendron species’ distributions in the region, with a view to helping develop strategies for conservation action and possible reintroductions.


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Diversity and Distribution of Rhododendrons in Arunachal Himalaya, India by Ashish Paul*, Mohamed Latif Khan, Ashesh Kumar Das and Pijush Kumar Dutta-  JOURNAL AMERICAN RHODODENDRON SOCIETY- FALL 2010.
Abstract– Rhododendron is one of the important dominant plant groups in the temperate, subalpine and alpine regions of western Arunachal Pradesh, India. The main aim of this study is to document Rhododendron biodiversity and conservation in western Arunachal Pradesh. The study area is the West Kameng and Tawang districts of Arunachal Pradesh, where extensive field surveys were made on a bimonthly basis. A total of 47 Rhododendron taxa were recorded from these two districts, which cover 16.4% of the geographic area of the state, from a total of 90 reported from all of Arunachal Pradesh. Sizes of different taxa ranged from tiny shrubs to large trees, and a majority belonged to the subgenus Hymenanthes. We document
three species as new to Arunachal Pradesh, and 13 species are endemic, endangered, rare or threatened. Maximum diversity of Rhododendron was observed between 2000 to 4000 m (6560–13,125 feet) elevation. Rhododendron formed a dominant vegetation type, comprising a fragile ecosystem in the timberline zone that included other plants and animals over this altitudinal gradient. Thus, we consider Rhododendron a keystone plant in the western part of Arunachal Pradesh.
Species listed:
R. anthopogon
R. arboreum
R. arboreum ssp. arboreum
R. arboreum ssp. cinnamomeum
R. arboreum ssp. delavayi var. delavayi
R. arboreum ssp. delavayi var. peramoenum
R. barbatum
R. bhutanense
R. camelliiflorum
R. campanulatum
R. campylocarpum
R. x candelabrum
R. ciliatum
R. cinnabarinun
R. coxianum
R. dalhousiae
R. dalhousiae var. rhabdotum
R. edgeworthii
R. falconeri
R. falconeri ssp. eximium
R. flinckii
R. fulgens
R. glaucophyllum var. tubiforme
R. grande
R. griffithianum
R. hodgsonii
R. hookeri
R. kendrickii
R. kesangiae
R. kesangiae var. album
R. keysii
R. lanatum
R. lepidotum
R. lindleyi
R. maddenii
R. megeratum
R. neriiflorum ssp. phaedropum
R. niveum
R. pendulum
R. setosum
R. x sikkimense
R. tanastylum
R. thomsonii
R. triflorum
R. virgatum
R. wallichii
R. wightii

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Rhododendron rawatii (Ericaceae), a new species from the Western Himalaya, India by ISHWARI DATT RAI & BHUPENDRA SINGH ADHIKARI*- Phytotaxa 71: 10–16 (2012)
Abstract: A new species of Rhododendron, R. rawatii is illustrated and described from the Western Himalaya. The species is sporadically found in the subalpine–timberline zone of Uttarakhand state. Fascicled white cottony hairs on the abaxial surface in between lateral veins of leaves, bright pink and shine-less corolla and comparatively large calyx with hairy margins distinguish the new species from its nearest ally R. fulgens. The populations of the species were found in two geographically distinct localities in the Rudraprayag and Pithoragarh districts of Uttarakhand state. The distinguishing morphological characters, affinities with other species and various ecological aspects of the new species are discussed here.


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Binomial Habit Notes References Distribution
Rhododendron
arboreum
J.E. Smith subsp. nilagirium (Zenk.) Tagg.
Tree/ shrub Western Ghats,
Evergreen Forests
Flora of Tamil
Nadu, VOL. II, 1987
Dindigul ,
Nilgiri
Rhododendron indicum (L.) Sweet Shrub Western
Ghats, Cultivated, Native of East
Asiatic  Region
Flora
of Tamil Nadu, VOL. II, 1987
Dindigul,
Nilgiri
Rhododendron mucronatum G.Don Shrub Western
Ghats, Cultivated Native of Himalayas
Flora
of Tamil Nadu, VOL. II, 1987; Matthew 1999
Dindigul
Rhododendron ponticum L. Shrub/ small
tree
Western
Ghats, Cultivated Native of Himalayas
Flora
of Tamil Nadu, VOL. II, 1987; Matthew 1999
Dindigul
Rhododendron simsii Planch. Shrub Western
Ghats, Cultivated, Native of East
Asiatic  Region
Flora
of Tamil Nadu, VOL. II, 1987; Matthew 1999
Dindigul

Botanical name Synonyms Family Common name
Rhododendron anthopogon Rhododendron anthopogon var. album Ericaceae Dwarf Rhododendron
Rhododendron arboreum subsp. nilagiricum Rhododendron nilagiricum, Rhododendron arboreum var. nilagiricum Ericaceae Nilgiri Rhododendron
Rhododendron arboreum Ericaceae Tree Rhododendron
Rhododendron brachycarpum Ericaceae Short Fruited Azalea
Rhododendron campanulatum subsp. aeruginosum Ericaceae Pink Bell Rhododendron
Rhododendron campanulatum Ericaceae Bell Rhododendron
Rhododendron cephalanthum Rhododendron chamaetortum Ericaceae Flowering Head Rhododendron
Rhododendron ciliatum Ericaceae Fringed Leaf Rhododendron
Rhododendron cinnabarinum Ericaceae Cinnabar Rhododendron
Rhododendron dalhousieae Ericaceae Lady Dalhousie Rhododendron
Rhododendron decipiens Ericaceae Deceptive Rhododendron
Rhododendron fulgens Ericaceae Shining Rhododendron
Rhododendron hodgsonii Ericaceae Hodgson’s Rhododendron
Rhododendron hypenanthum = Rhododendron degronianum var. heptamerum (Maxim.) Sealy ex Davidian Rhododendron anthopogon var. hypenanthum Ericaceae Yellow Dwarf Rhododendron
Rhododendron keysii Rhododendron keysii var. unicolor Ericaceae Keys Rhododendron
Rhododendron lepidotum ssp. salignum Rhododendron salignum Ericaceae Willow-Leaved Rhododendron
Rhododendron lepidotum Ericaceae Pink Scaly Rhododendron
Rhododendron lepidotum Ericaceae Yellow Scaly Rhododendron
Rhododendron lindleyi Rhododendron bhotanicum Ericaceae Maddenia Rhododendron
Rhododendron neriiflorum ssp. phaedropum Rhododendron tawangense Ericaceae Tawang Rhododendron
Rhododendron nivale Ericaceae Snow Rhododendron
Rhododendron setosum Ericaceae Bristly Rhododendron
Rhododendron thomsonii Ericaceae Thomson’s Rhododendron
Rhododendron wallichii Ericaceae Wallich’s Rhododendron
Rhododendron wightii Ericaceae Wight’s Rhododendron


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1997 IUCN Red List of Threatened Plants edited by Kerry Scott Walter, Harriet J. Gillett-
R. concinnoides Hutch. & Kingdon-Ward- Endangered- Arunachal Pradesh
R. elliottii Watt- Indeterminate- Manipur & Nagaland
R. formosum Kingdon-Ward – Vulnerable- Arunachal Pradesh, Manipur, Meghalaya & Nagaland
R. johnstoneanum Watt ex Hutch.- Indeterminate- Manipur & Mizoram
R. macabeanum Watt ex Balf. f.- Rare- Manipur & Nagaland
R. santapaui Sastry, Kataki, P. Cox, Patricia Cox & P. Hutch.- Endangered- Arunachal Pradesh
R. subansiriense D. F. Chamb. & Cox- Endangered- Arunachal Pradesh

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Forest Plants of Eastern India By Amal Bhusan Chaudhuri (1993)- Brief details with keys-
R. anthopogon D. Don
R. arboreum Sm.
R. barbatum G. Don
R. camelliaeflorum Hook. f.
R. campylocarpum Hook. f.
R. cinnabarinum Hook. f.
R. dalhousiae Hook. f.
R. edgeworthii Hook. f.
R. falconeri Hook. f.
R. fulgens Hook. f.
R. glaucum
R. grande Wight
R. griffithianum Wight
R. hodgsonii Hook. f.
R. lanatum Hook. f.
R. lepidotum Wall. ex D. Don
R. maddenii Hook. f.
R. nivale Hook. f.
R. niveum Hook. f.
R. pendulum Hook. f.
R. setosum D. Don
R. thomsonii Hook. f.
R. triflorum Hook. f.
R. vaccinioides Hook. f.
R. virgatum Hook. f.
R. wightii Hook. f.

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Rhododendron :  3 posts by 1 author.

I have updated eFI (efloraofindia) page on  Rhododendron

Attempts have been made to incorporate most of the species available in India & nearby areas with details & keys directly or through links as far as possible. It’s quite possible that there may be some discrepancy in the accepted names & synonyms taken from other links.

Species discussed so far in efloraofindia are given at the bottom of the page in the form of links against Subpages. On clicking them one can see all the details.

Any comments/ corrections are welcome.


Its a good effort. many species/taxa given are not found in India. At present 128 taxa are reported from India.


Thanks, … I have done the needful pl.


Pl. go through Rhododendron (‎‎‎‎‎‎‎‎‎‎Ericaceae) page with images of species in efloraofindia.

If you find any incorrect identification, pl. let us know. If anybody can send images of other species of this genera (for incorporation in the website), if any, or can identify unidentified images, it will be really nice.


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Fwd: Identifying plans from a coach/bus…. : 1 post by 1 author. Attachments (1)
I have just posted about identifying plants from a railway carriage.  This made me think about the two botanical tours I led to Himachal Pradesh is the mid-1980s. The majority of the time we were trekking in the Miyah Nullah, Lahaul.  On the first occasion I came in as a last-minute
replacement for the Late Oleg Polunin (co-author of ‘Flowers of the Himalaya’).
To reach Udaipur, the starting point of our trek, my party was driven in a private bus/coach.  It proved a mentally exhausting day for me, as I was constantly being asked to identify the plants which individuals could see through the windows – often on both sides of the bus.  Fortunately, I knew most of the prominent ones following visits to Ladakh and Kashmir.  In addition, IF one is familiar with wild and garden plants in the UK, the genus of most plants seen from the Rohtang onwards will be recognisable.
Nevertheless, it was very hard work.  We had 2 or 3 stops in promising locations.  Although we had spent a couple of days in Manali (at about 2200m or so) to help us acclimatise, us Britishers, accustomed to living at sea-level in the UK, certainly felt the altitude at the of the Rohtang Pass (c. 3900m).  It was a relief to drop back down in elevation in Lahaul, spending the night at some 2700m.
IF one can recognise a particular genus and is aware of which species belonging to the genus are found in H.P., this can greatly narrow down the possibilities.  Take Rhododendron for example.  There are c. 30 species found in the parts of the Himalaya covered by ‘Flowers of the Himalaya’ (more species if one adds Sikkim & Bhutan).
Of these, only 4 are known from the NW Himalaya (which includes H.P.). Once one reaches the Rohtang proper, then elevation-wise, R.arboreum is no longer present.  That just leaves R.campanulatum (which is a large shrub) plus R.lepidotum and R.anthopogon – smaller shrubs to shrublets.  By the time one is exploring above the Rohtang Pass @ 4000m+, the dwarf strongly aromatic shrublet with yellowish to creamy-white flowers encountered must surely be Rhododendron anthopogon only.
Thus, even from a bus, I can recognise each species of Rhododendron in H.P.  In Sikkim or Bhutan it would be another matter – not that one gets to view many Rhodendrons along roads in these parts.  One must trek.
Much the same applies to images of Rhododendron photographed in H.P.  Even without close-ups and despite the images not being in good focus, it is possible to confidently name almost all photos of this genus from the NW Himalaya.   As one explores into the Eastern Himalaya, things become much more difficult, with many more species of Rhododendron to consider – quite a number of which I have never come across myself and know little about.
See image attached of some members of my botanical tour in the 1980s on the Rohtang looking for Primula munroi to photograph.

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Rhododendron species in India :
I have also added list of species of Rhododendron L. (Ericaceae) in India based on the document published by BSI in 2014.

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Rhododendron sp. from Sikkim! : Attachments (1)  – 48 species and subspecies shown as comparative images.
Enclosing  list/images of Rhododendron sp.of Sikkim. I hope it would help us to ID in future!