标题：大关杜鹃
形态特征
[1]幼枝细长，近于轮生，密被绢状棕褐色糙伏毛；老枝深褐色，杜鹃(16张)被褐色毛或变为无毛。叶厚纸质，散生，披针形。卵状披针形或椭圆状披针形，长 2.5-8.5厘米，中部宽达3厘米，先端渐尖，具短尖头，基部楔形或宽楔形，全缘，上面深绿色，中脉及4-5对侧脉，凹陷，下面显著凸出，侧脉未达叶缘隐失不见，两面密被棕褐色糙伏毛；叶柄长3-8毫米，被棕褐色糙伏毛。花芽卵球形，鳞片顶端短尖，外面沿中脊被刚毛，边缘具细睫毛。伞形花序顶生，有花2-4(7)朵；花梗长8毫米，密被棕褐色扁平糙伏毛；花萼极小，裂开三角状卵形；花冠红色，漏斗形，长2.2厘米，5裂，裂片长圆形，顶端钝尖，具深红色斑点，花冠管狭圆筒状，外面无毛，内面被微柔毛，先端突然扩大；雄蕊10，不等长，长约与花冠相等，花丝线形，中部以下被微柔毛；子房圆锥状卵球形，长5毫米，密被亮棕褐色糙伏毛，花柱比雄蕊长，无毛。蒴果长卵球 形，长6毫米，直径4毫米，密被棕褐色长糙伏毛。[2]
  大关杜鹃    炎陵云锦杜鹃花  杜鹃花    大关杜鹃  大关杜鹃  大关杜鹃
相近品种
大关杜鹃[3]与杜鹃R.simsii Planch.[4]相似，但不同之处在于大关杜鹃的花冠长2.2厘米，花冠管狭圆筒状；叶披针形或椭圆状披针形，颜色有部分差异，故易于区别。[2]
相关的种
腺花杜鹃Rhododendron adenanthum M. Y. He 
短鳞芽杜鹃Rhododendron breviperulatum Hayata 
金萼杜鹃Rhododendron chrysocalyx H. Lév. & Vant. 
金萼杜鹃（原变种）Rhododendron chrysocalyx H. Lév. & Vant. var. chrysocalyx 
秀山金萼杜鹃（变种）Rhododendron chrysocalyx H. Lév. & Vant. var. xiushanense (Fang) M. Y. He 
龙山杜鹃Rhododendron chunii Fang 
棒柱杜鹃Rhododendron crassimedium P. C. Tam 
粗柱杜鹃Rhododendron crassistylum M. Y. He 
白枝杜鹃Rhododendron cretaceum P. C. Tam
龙岩杜鹃Rhododendron florulentum P. C. Tam
子花杜鹃Rhododendron flosculum Fang & G. Z. Li
河边杜鹃Rhododendron flumineum Fang & M. Y. He
贵定杜鹃Rhododendron fuchsiifolium H. Lév.
棕毛杜鹃Rhododendron fuscipilum M. Y. He
腺柱杜鹃Rhododendron glandulostylum Fang & M. Y. He
海南杜鹃Rhododendron hainanense Merr.
合江杜鹃Rhododendron hejiangense M. Y. He
湖南杜鹃Rhododendron hunanense Chun ex P. C. Tam 
背绒杜鹃Rhododendron hypoblematosum P. C. Tam
皋月杜鹃Rhododendron indicum (L.) Sweet
素馨杜鹃Rhododendron jasminoides M. Y. He 
金平杜鹃Rhododendron jinpingense Fang & M. Y. He
金秀杜鹃Rhododendron jinxiuense Fang & M. Y. He
台北杜鹃Rhododendron kanehirae E. H. Wils.
广西杜鹃Rhododendron kwangsiense Hu ex P. C. Tam
广西杜鹃〔原变种）Rhododendron kwangsiense Hu ex P. C. Tam var. kwangsiense
钝圆杜鹃（变种）Rhododendron kwangsiense Hu ex P. C. Tam var. obovatifolium P. C. Tam 
广东杜鹃Rhododendron kwangtungense Merr. & Chun
毛花柱杜鹃Rhododendron lasiostylum Hayata
荔叶杜鹃Rhododendron litchiifolium T. C. Wu & P. C. Tam
长尖杜鹃Rhododendron longifalcatum P. C. Tam
长鳞芽杜鹃Rhododendron longiperulatum Hayata
忍冬杜鹃Rhododendron loniceriflorum P. C. Tam
麻栗坡杜鹃Rhododendron malipoense M. Y. He
岭南杜鹃Rhododendron mariae Hance
南边杜鹃Rhododendron meridionale P. C. Tam
南边杜鹃（原变种）Rhododendron meridionale P. C. Tam var. meridionale
狭叶南边杜鹃（变种）Rhododendron meridionale P. C. Tam var. minus P. C. Tam
糙柱杜鹃（变种）Rhododendron meridionale P. C. Tam var. setistylum P. C. Tam
亮毛杜鹃Rhododendron microphyton Franch.
亮毛杜鹃（原变种）Rhododendron microphyton Franch. var. microphyton 
碧江亮毛杜鹃（变种）Rhododendron microphyton Franch. var. trichanthum A. L. Chang ex R. C. Fang
小花杜鹃Rhododendron minutiflorum Hu
白花杜鹃Rhododendron mucronatum (Bl.) G. Don
铁仔叶杜鹃Rhododendron myrsinifolium Ching ex Fang & M. Y. He
南昆杜鹃Rhododendron naamkwanense Merr. 
紫薇春（变种）Rhododendron naamkwanense Merr. var. cryptonerve P. C. Tam
南昆杜鹃（原变种）Rhododendron naamkwanense Merr. var. naamkwanense
那克哈杜鹃Rhododendron nakaharae Hayata 
南平杜鹃Rhododendron nanpingense P. C. Tam 
钝叶杜鹃Rhododendron obtusum (Lindl.) Planch. 
八蕊杜鹃Rhododendron octandrum M. Y. He 
砖红杜鹃Rhododendron oldhamii Maxim.
千针叶杜鹃Rhododendron polyraphidoideum P. C. Tam 
岭上杜鹃（变种）Rhododendron polyraphidoideum P. C. Tam var. montanum P. C. Tam 
千针叶杜鹃（原变种）Rhododendron polyraphidoideum P. C. Tam var. polyraphidoideu
美艳杜鹃Rhododendron pulchroides Chun & Fang
锦绣杜鹃Rhododendron pulchrum Sweet
黔阳杜鹃Rhododendron qianyangense M. Y. He
淡红杜鹃Rhododendron rhodanthum M. Y. He
乳源杜鹃Rhododendron rhuyuenense Chun ex P. C. Tam
溪畔杜鹃Rhododendron rivulare Hand.-Mazz.
台红毛杜鹃Rhododendron rubropilosum Hayata
滇红毛杜鹃Rhododendron rufohirtum Hand.-Mazz.
茶绒杜鹃Rhododendron rufulum P. C. Tam
崖壁杜鹃Rhododendron saxatile B. Y. Ding & Y. Y. Fang
毛果杜鹃Rhododendron seniavinii Maxim.
杜鹃Rhododendron simsii Planch.
蔗黄杜鹃Rhododendron spadiceum P. C. Tam
川南杜鹃Rhododendron sparsifolium Fang
腊黄杜鹃Rhododendron subcerinum P. C. Tam
隐脉杜鹃Rhododendron subenerve P. C. Tam
涧上杜鹃Rhododendron subflumineum P. C. Tam
大埔杜鹃Rhododendron taipaoense T. C. Wu & P. C. Tam
细瘦杜鹃Rhododendron tenue Ching ex Fang & M. Y. He
薄片杜鹃Rhododendron tenuilaminare P. C. Tam
鼎湖杜鹃Rhododendron tingwuense P. C. Tam
两广杜鹃Rhododendron tsoi Merr.
垂钩杜鹃Rhododendron unciferum P. C. Tam
粘质杜鹃Rhododendron viscidum C. Z. Guo & Z. H. Liu
粘芽杜鹃Rhododendron viscigemmatum P. C. Tam 
阳明山杜鹃Rhododendron yangmingshanense P. C. Tam 
瑶山杜鹃Rhododendron yaoshanicum Fang & M. Y. He[5]