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大喇叭杜鹃Rhododendron excellens Hemsl. et Wils.

大喇叭杜鹃Rhododendron excellens Hemsl. et Wils.

别名:优秀杜鹃;

科名:杜鹃花科 Ericaceae

属名:杜鹃属 Rhododendron

《中国植物志》第57(1)卷030页
  8.大喇叭杜鹃(中国高等植物图鉴)图版5:6-7
  Rhododendron excellens Hemsl. et Wils. in Kew Bull. 1910: 113. 1910; Hutch. in Not. Bot. Gard. Edinb. 12: 30. 1919; id. in Stevenson, Spec. Rhodod. 486. 1930; 中国高等植物图鉴3: 34. 图4021. 1974; Cullen in Not. Bot. Gard. Edinb. 39: 36. 1980; 云南植物志4: 471. 图版126, 3-5. 1986; 贵州植物志3: 200. 1990.——R. sinonuttallii auct. non Balf. f. et Forrest: Fang in Contr. Biol. Lab. Sci. Soc. China Bot. 12: 73. 1939.
  灌木,高1.5-3米,有时为高约5米的小乔木。幼枝褐紫色,圆柱形,密被暗褐色鳞片。叶常绿,革质,长圆状椭圆形,长11-19厘米,宽3.5-8厘米,顶端钝尖,基部圆,有时微凹入稍呈耳状,幼时上面散生鳞片,以后洁净,下面苍白色,密被大小不等的褐色鳞片,小鳞片相距为其直径,或2倍于直径或小于直径,大鳞片散生其间,有时脱落,中脉在上面平坦,下面明显突起;叶柄长1.5-3厘米,暗紫色,圆柱形无凹槽,密被鳞片。花序顶生,3-4花伞形排列;花芽鳞早落;花梗粗壮,长1.2-2厘米,密被鳞片;花萼圆卵形,长0.8-1.2厘米,外面近基部被鳞片;花冠宽漏斗状,长9-11厘米,白色,外面被鳞片,在筒部更多,裂片圆形;雄蕊10,短于花冠筒,花丝下部被柔毛,花药长约8毫米;子房5室,密被鳞片,花柱略伸出花冠,下部1/2被鳞片,柱头扁球形。蒴果圆柱形,长4.5-5.5厘米,果瓣龙骨状突起,下部被以宿 存萼片,宿萼长1.5-1.8厘米。花期5月。
  产贵州南部、云南东南部。生于常绿、落叶混交林地或灌丛中,海拔1 100-2 400长。模式标本采自云南蒙自红河以南。
形态特征:灌木,高1.5—3米,有时为高约5米的小乔木。幼枝褐紫色,圆柱形,密被暗褐 色鳞片。叶常绿,革质,长圆状椭圆形,长11—19厘米,宽3.5—8厘米,顶端钝尖, 基部圆,有时微凹人稍呈耳状,幼时上面散生鳞片,以后洁净,下面苍白色,密被大小 不等的褐色鳞片,小鳞片相距为其直径,或2倍于直径或小于直径,大鳞片散生其间, 有时脱落,中脉在上面平坦,下面明显突起;叶柄长1.5--3厘米,暗紫色,圆柱形天 凹槽,密被鳞片。花序顶生,3—4花伞形排列;花芽鳞早落;花梗粗壮,长1.2—2厘 米,密被鳞片;花萼圆卵形,长0.8—1.2厘米,外面近基部被鳞片;花冠宽漏斗状, 长9—11厘米,白色,外面被鳞片,在筒部更多,裂片圆形;雄蕊10,短于花冠筒, 花丝下部被柔毛,花药长约8毫米;子房5室,密被鳞片,花柱略伸出花冠,下部“ 被鳞片,柱头扁球形。蒴果圆柱形,长4.5—5.5厘米,果瓣龙骨状突起,下部被以宿存萼片,宿萼长1.5—1.8厘米。 花期5月。
产地分布:产贵州南部、云南东南部。生于常绿、落叶混交林地或灌丛中,诲拔1100—2 400 米。模式标本采自云南蒙自红河以南
参考文献:Rhododendron excellens Hemsl.Et WiN,in Kew Bull.1910:113.1910;Hutch.I Not.B)t.Gard.Edinb.12:30. 1919;id,inStevenson,Spec.Rhodod.486. 1930;中 国高等植物图鉴3:34. 图4021.1974;Cullen in Not.Bot.Gard.Edinb.39:36. 1980;云南植物志4:471.图版126,3—5.1986;贵州植物志3:200.1990.—— R.Sinonuttallii auct.Non Balf.f.Et Forrest:Fang in Contr.Bi01.Lab,Sci.Soc.China Bot.12:73.1939.
亚组概述:Subsect.Maddenia(Hutch.)Sleumer in Bot.Jahrb.74: 533.1949.--Ser.Maddenii setisu Hutch.In Not.Bot.Gard.Edinb.12:1.1919 ct in Stevenson,Spec.Rhodod.447.1930;Davidian.Rhodod.Spec.1:259.1982. 中等大小至大灌木或小乔木,常绿,附生或地生。幼枝被鳞片,有时有毛。叶革 质,下面通常密被大小不等的鳞片。花序顶生,1至多花,伞形或短总状着生;花萼发 育或不发育,裂片大者通常无缘毛,短小者常有长缘毛;花冠在本亚属中最长大,外面 通常有鳞片,简部常有柔毛;雄蕊10—25,通常10枚,花丝下部密被柔毛,稀无毛; 子房5—12室,通常5—6室,密被鳞片,花柱伸长,稀短于雄蕊,略弯,下部或基部 总是有鳞片,稀光滑。蒴果通常大,卵状长圆形、卵球形或圆筒形,长(0.5)1—7厘 米,密被鳞片。种子有翅和有鳍状物。 亚组的模式种:隐脉杜鹃Rhododendron maddenii Hook.F. 本亚组约44种,分布沿东喜马拉雅至中南半岛,即印度东北、尼泊尔、锡金、不 丹、中国西南、缅甸、泰国、老挝、越南。我国产32种,集中分布西藏、云南,星散 布于四川、贵州、广西、广东、福建、江西、湖南。

《Flora of China》 Vol. 14 (2005)
Rhododendron excellens  Hemsley & E. H. Wilson
大喇叭杜鹃   da la ba du juan
Shrubs, sometimes small trees, 1.5–3(–5) m tall; young branches brownish purple, cylindric, densely dark brown scaly. Petiole not grooved, 15–30 mm, densely scaly; leaf blade leathery, oblong-elliptic, 11–19 × 3.5–8 cm; base rounded, sometimes slightly cordate to auriculate; apex acuminate; abaxial surface dirty white; adaxial surface sparsely scaly when young, glabrescent; midrib raised abaxially, concave adaxially. Inflorescence terminal, umbellate, 3–4-flowered; bud scales falling off early. Flowers fragrant. Pedicel stout, 1.2–2 cm, densely scaly; calyx lobes ovate, 8–12 mm, persistent in fruit, 1.5–1.8 cm, scaly at base; corolla broadly campanulate, white, 9–11 cm, outer surface scaly; lobes rounded; stamens 10(or 11 or 15), shorter than corolla tube; filaments pubescent below; anthers ca. 8 mm; ovary 5-locular, densely scaly; style slightly exserted from corolla tube, basal half scaly; stigma discoid. Capsule cylindric, lobes keeled, 45–55 mm. Fl. May.
Evergreen broad-leaved forests or thickets; 1100–2400 m. S Guizhou, SE Yunnan [N Vietnam].
Rhododendron excellens was originally described as having 15 stamens, which does not agree with this description. One solution would be to describe those plants with 10(–11) stamens as a new taxon, which could be called “var. decandrum”. This would account for the vast majority of the specimens available. It is possible that the type of R. excellens was a chance hybrid between “var. decandrum” and R. maddenii subsp. crassum. In Vietnam, where the distribution of “var. decandrum” overlaps with that of R. nuttallii (which it closely resembles), there appear to be intermediates between the two taxa.

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