栏目

菱形叶杜鹃Rhododendron rhombifolium R. C. Fang

菱形叶杜鹃Rhododendron rhombifolium R. C. Fang

别名:

科名:杜鹃花科 Ericaceae

属名:杜鹃属 Rhododendron

《中国植物志》第57(1)卷043页
  26.菱形叶杜鹃(云南植物研究)
  Rhododendron rhombifolium R. C. Fang in Act. Bot. Yunn. 4: 251. 图3. 1982; 云南植物志4: 481. 图版129, 3-4. 1986;横断山区维管植物下册1423. 1994.
  灌木,通常附生,高2-3米。幼枝密被褐色鳞片,老枝灰色。叶聚生枝顶,菱状椭圆形或菱状披针形,长5-8.5厘米,宽2-3厘米,顶端渐尖,基部楔形,幼叶边缘疏生褐色长刚毛,上面洁净无鳞片,下面干后褐色,密被大鳞片,鳞片褐红色,有宽边缘,不等大,相距小于直径,中脉在叶面凹陷,在下面凸起,侧脉纤细,在两面均不显,网脉在叶面明显;叶柄短,长0.5-1.2厘米,密被褐色鳞片,初时两侧生褐色长刚毛,以后脱落。花末见。果序有果3-4个,伞形着生;果梗粗壮,长0.6-1厘米,密被褐色鳞片;蒴果卵珠状或长圆形,密被褐色鳞片,6瓣开裂;宿存萼片长2毫米,波状,边缘密生褐色刚毛,宿存花柱下部1/3被鳞片。
  产云南贡山。生于山坡阔叶林中或附生于密林中树上,海拔1 800-1 900米。模式标本采自贡山。
  本种缺花标本,由于宿存花柱断落,果标本不完整,其位置暂置于有鳞大花亚组。
形态特征:灌木,通常附生,高2—3米。幼枝密被褐色鳞片,老枝灰色。叶聚生枝顶,菱状 椭圆形或菱状披针形, 长5--8.5厘米,宽2--3厘米,顶端渐尖,基部楔形,幼叶边缘 疏生褐色长刚毛, 上面洁净无鳞片,下面干后褐色,密被大鳞片,鳞片褐红色,有宽边 缘,不等大,相距小于直径,中脉在叶面凹陷,在下面凸起,侧脉纤细,在两面均不 显,网脉在叶面明显;叶柄短,长0.5—1.2厘米,密被褐色鳞片,初时两侧生褐色长刚 毛,以后脱落。花末见。果序有果3--4个,伞形着生;果梗粗壮,长0.6—1厘米,密被褐 色鳞片;蒴果卵珠状或长圆形,密被褐色鳞片,6瓣开裂;宿存萼片长2毫米,波状, 边缘密生褐色刚毛,宿存花柱下部1/3被鳞片。
产地分布:产云南贡山。生于山坡阔叶林中或附生于密林中树上,海拔1 800—1 900米。模式 标本采自贡山。
本种提示:本种缺花标本,由于宿存花柱断落,果标本不完整,其位置暂置于有鳞大花亚组。
参考文献:Rhododendron rhombifolium R.C.Fang in Act.Bot.Yunn.4:251.图3.1982; 云南植物志4:481.图版129,3—4.1986;横断山区维管植物下册1423.1994.
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 rhombifolium  R. C. Fang
菱形叶杜鹃   ling xing ye du juan
Shrubs, often epiphytic, 2–3 m tall; old branches gray; young shoots densely brown-scaly. Petiole short, 5–12 mm, densely brown-scaly; hispid on both surfaces when young, glabrescent; leaf blade rhomboidal or rhomboidal-lanceolate, 5–8.5 × 2–3 cm; base cuneate; apex acuminate; abaxial surface brown when dry, scales less than 1 × their own diameter apart, large, unequal, brownish red; adaxial surface glabrous; midrib raised abaxially, concave adaxially; lateral veins thin, inconspicuous on both surfaces. Flowers not seen, infructescence umbellate, 3- or 4-fruited. Pedicel stout, 0.6–1 cm, densely brown-scaly; fruiting calyx margin wavy, ciliate, ca. 2 mm, persistent; style persistent, basal 1/3 with scales. Capsule cylindric or ovoid-cylindric, 6-lobed, 12–20 × 8–12 mm, densely brown-scaly.
Broad-leaved forests, sometimes epiphytic on trees in dense forests; 1800–1900 m. Yunnan.
The leaf shape of Rhododendron rhombifolium is close to that of the sympatric R. taronense, but the clearly ciliate calyx of the former distinguishes the two species. Flowering material is required before the true affinities of R. rhombifolium can be ascertained, as the type specimen is in fruit. The label on the isotype at E (“Salwin-Kiukiang Divide, Muchielung, 1800 m, 8 Oct. 1938, T. T. 20581”) is somewhat at variance with the citation in the protologue (“Gongshan, ad truncos in sylvis densis, alt. 1800 m, 8 Oct. 1937, T. T. 20581”).

TOP