栏目

乳源杜鹃Rhododendron rhuyuenense Chum ex Tam

乳源杜鹃Rhododendron rhuyuenense Chum ex Tam

别名:

科名:杜鹃花科 Ericaceae

属名:杜鹃属 Rhododendron

《中国植物志》第57(2)卷414页
  320. 乳源杜鹃(中国高等植物图鉴)图版131:1-4
  Rhododendron rhuyuenense Chun ex Tam, Survey Rhodod. South China 32 et 95. f. 2. 1983. ——R. lingii Chun ex Ching中国高等植物图鉴3: 151. 图4256. 1974.
  半常绿灌木,高3米;小枝灰褐色,被长刚毛和短腺毛。叶革质,簇生枝端,椭圆状披针形、长披针形或阔卵形,长2.5-6.5厘米,宽1.5-3(-4.5 )厘米,先端渐尖,具短尖头,基部近于圆形,微不对称,边缘反卷,具长刚毛,稀具短腺头毛,上面于后深褐色,下面棕褐色,叶脉在上面凹陷,下面凸起,侧脉未达叶缘连结,上面除沿中脉残存刚毛外,近于无毛,下面散生刚毛或残留粗糙的毛基;叶柄长0.4-1厘米,密被棕褐色长刚毛和短腺头毛。花芽粘结,鳞片阔卵形,外面近顶端具淡黄棕色糙伏毛和腺体。伞形花序顶生,有花达12朵;花梗长8-10毫米,密被棕褐色长刚毛和短腺毛;花萼小,5浅裂,裂片卵形或三角状卵形,密被长刚毛状糙伏毛;花冠粉红色或粉红带紫蓝色,辐状钟形,长1厘米,花冠管较粗壮,长5毫米,基径4毫米,外面被腺毛,内面被微柔毛,5深裂,裂片开展,卵形,长与花冠管等长,上部裂片具红色斑点;雄蕊5,不等长,长1.5-1.8厘米,伸出冠外较长,花丝扁平,中部以下被微柔毛;子房卵球形,被棕褐色刚毛和腺毛,花柱比雄蕊短,长约1.2厘米,中下部被红棕色长刚毛和腺毛,柱头5裂,深褐色。蒴果卵球形,长5-6毫米,直径4毫米,被深褐色长刚毛。花期5-6月,果期7-11月。
  产江西东部、湖南南部、广东北部。生于海拔1 500米以下的阳坡疏林或灌丛中。模式标本采自广东乳源清溪洞。
  本种与毛果杜鹃 R. seniavinii Maxim.相近,但不同在于本种的小枝、叶柄、花梗均具长刚毛和短腺毛;花冠粉红色或粉红带紫蓝色;花柱比雄蕊短,易于区别。
形态特征:半常绿灌木,高3米;小枝灰褐色,被长刚毛和短腺毛。叶革质,簇尘枝端,椭圆状披针形,长披针形或阔卵形,长2.5—6.5厘米,宽1.5—3(--4.5)厘米,先端渐尖,具短尖头,基部近干圆形,微不对称,边缘反卷,具K刚毛,稀具短腺头毛,上面干后深褐色,下面棕褐色,叶脉在上面凹陷,下面凸起,侧脉未达叶缘连结,上面除沿中脉残存刚毛外,近于无毛,下面散生刚毛或残留粗糙的毛基;叶柄长0.4—1厘米,密被棕褐色长刚毛和短腺头毛。花芽粘结,鳞片阔卵形,外面近顶端具淡黄棕色糙伏毛和腺体。伞形花序顶生,有花达12朵;花梗长8—10毫米,密被棕褐色长刚毛和短腺毛;花萼小,5浅裂,裂片卵形或三角状卵形,密被长刚毛状糙伏毛:花冠粉红色或粉红带紫蓝色,辐状钟形,长1厘米,花冠管较粗壮,长5毫米,基径4毫米,外面被腺毛, 内面被微柔毛,5深裂,裂片开展, 卵形, 长与花冠管等长,上部裂片具红色斑点;雄蕊5, 不等长, 长1.5—1.8厘米,伸出冠外较长,花丝扁平,中部以下被微柔毛; 子房卵球形,被棕褐色刚毛和腺毛,花柱比雄蕊短,长约1.2厘米,中下部被红棕色长刚毛和腺毛,柱头5裂,深褐色。蒴果卵球形, 长5—6毫米,直径4毫米, 被深褐色长刚毛。 花期5—6月,果期7—11月。
产地分布:产江西东部、湖南南部、广东北部。生于海拔1500米以下的阳坡疏林或灌丛中。模式标本采自广东乳源清溪洞。
本种提示:本种与毛果杜鹃R.Seniavinii Maxim.相近,但不同在于本种的小枝、叶柄、 花梗均具长刚毛和短腺毛;花冠粉红色或粉红带紫蓝色;花柱比雄蕊短,易于区别。
参考文献:Rhododendron rhuyuenense Chun ex Tam,Survey Rhodod.South Chma 32 et96. F.2. 1983.——R.linfiii Chun ex Ching 中国高等植物图鉴3:1 51. 图4256.1974.

《Flora of China》 Vol. 14 (2005)
Rhododendron rhuyuenense  Chun ex P. C. Tam
乳源杜鹃   ru yuan du juan
Shrubs, to 3 m tall; shoots with long bristles and short glandular hairs. Summer and winter leaves different. Petiole 4–10 mm, densely long-setose and shortly glandular-hairy; leaf blade leathery, elliptic-lanceolate, long-lanceolate or broadly ovate, 2.5–6.5 × 1.5–3(–4.5) cm; base subrounded and slightly asymmetrical; margin revolute, long-setose, rarely shortly glandular-hairy; apex acuminate and mucronate; abaxial surface sparsely setose, setae may be reduced to swollen hair bases; adaxial surface subglabrous except for persistent setae along midrib, lateral veins not reaching the margin. Inflorescence ca. 12-flowered. Pedicel 0.8–1 cm, densely long brown-setose and shortly glandular-hairy; calyx lobes shallowly divided, ovate or triangular-ovate, small, densely coarsely long-strigose; corolla rotate-campanulate, pink or pink-purplish blue, the upper lobes with red flecks, ca. 1 cm; tube short, ca. 5 × 4 mm, outer surface glandular-hairy, inner surface puberulent; lobes spreading, ovate, as long as corolla tube; stamens 5, unequal, 1.5–1.8 cm, long-exserted, filaments puberulent at base; ovary ovoid, brown-setose and glandular-hairy; style ca. 1.2 cm, shorter than stamens, long red-brown-setose and glandular-hairy. Capsule ovoid, 5–6 × ca. 4 mm, long dark-setose. Fl. May–Jun, fr. Jul–Nov.
Open forests and thickets; 1500 m. N Guangdong, S Hunan, E Jiangxi.
This species was described (in Chinese) and illustrated under the name “Rhododendron lingii Chun” (Ching, Iconogr. Cormophyt. Sin. 3: 151, t. 4256. 1974), which was not validly published.

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