海南紫珠属5种植物的木材解剖学研究

Wood Anatomy Research on Five Plants of Callicarpa L. in Hainan

摘要: 为更好地识别海南产紫珠属(Callicarpa L.) 5种植物，即杜虹花(C. formasana Rolfe)、裸花紫珠(C. nudiflora Vahl)、红腺紫珠(C. erythrosticta Merr. & Chun)、短柄紫珠[C. brevipes (Benth.) Hance] 及散花紫珠[C. kochiana var. laxiflora (H. T. Chang) W. Z. Fang] 的木材解剖学特征，本文对上述植物的树皮、木材宏观及微观构造进行了详细的观测和描述。对上述五者的研究表明：树皮极薄，厚度为0.7~1.4 mm；而树皮颜色、皮孔略有不同。宏观特征：共同特征在于心边材区别不明显；散孔材；管孔大小略一致；轴向薄壁组织无或不明显；横切面上木射线清晰，较细密，常比管孔小；弦切面上呈银白色细线状；径切面上射线斑纹明显。不同特征在于髓心形状、生长轮大小、侵填体数量、内涵韧皮部有无等，其中杜虹花和裸花紫珠的髓心形状分别呈近六边形和近四方形，较为特殊，其他呈近圆形至椭圆形；短柄紫珠生长轮最窄(8~10轮/cm)，而裸花紫珠最宽(1.5~2轮/cm)；杜虹花和散花紫珠的侵填体较多；短柄紫珠和散花紫珠横切面上可见明显的长条状内涵韧皮部。微观特征：共同特征在于单管孔和径列复管孔(2~4个)为主，管间纹孔式互列；木射线非叠生，常同一列射线出现2次以上多列的部分。不同特征在于管孔密度、木射线类型、射线大小等，其中红腺紫珠的管孔密度最小(20~30个/mm²)，短柄紫珠管孔密度最大(80~100个/mm²)；裸花紫珠木射线类型以异形Ⅲ型为主，而其它4种以异形Ⅱ型为主；短柄紫珠的多列木射线常宽2细胞(稀3细胞)，其他4种宽2~5细胞。与同科的柚木(Tectona grandis L.f.)和石梓(Gmelina chinensis Benth.)的比较研究表明，紫珠属植物在木材类型、管孔大小、管孔密度、管孔弦径、轴向薄壁组织、内涵韧皮部、木射线数量、木射线类型等方面与上述两属的木材构造具有一定的差异。综上所述，5种紫珠属植物的木材解剖构造上有很多相似之处，但也存在差异，本研究将为该属植物的木材鉴定与应用、系统分类和植物保护等方面提供依据。

Abstract: In order to better identify the wood anatomical characteristics of five species of Callicarpa L. plants in Hainan, namely C. formasana Rolfe, C. nudiflora Hook. & Arn., C. erythrosticta Merr. & Chun, C. brevipes (Benth.) Hance and C. kochiana var. laxiflora (H. T. Chang) W. Z. Fang, this paper has carried out detailed observations and descriptions of the macro-structure and micro-structure of these plants wood and bark. The experiment results of the five species indicated that: the barks were extremely thin, with a thickness of 0.7~1.4 mm, but the color and lenticel of the bark were different. Macroscopic features: The common characteristics were that the difference between heartwood and sapwood was not obvious; diffuse-porous wood; pores size was slightly consistent; axial parenchyma was absent or not obvious; xylem rays were clear, relatively fine, and often smaller than pores on the cross-section; it appeared as silver white fine lines on the tangential section; the xylem ray stripes were obvious on the radial section. The different characteristics were that the shape of pith, the size of growth ring, the number of tyloses, and the presence or absence of interxylary phloem, ect. Among them, the pith shapes of C. formasana and C. nudiflora were nearly hexagonal and nearly quadrilateral respectively, which are relatively special, while the others were nearly round to oval. The growth ring of C. brevipes was the narrowest (8~10 r/cm), while C. nudiflora was the widest (1.5~2 r/cm). There were many tyloses in C. formasana and C. kochiana var. laxiflora. There were obviously long strip of interxylary phloem on the cross section of C. brevipes and C. kochiana var. laxiflora. Microscopic features: The common characteristics were that mainly solitary pore and radial multiple pore (2~4), intervessel pitting alternate; the xylem rays non overlapping, frequent occurrence twice or more multiseriate parts in the same ray. The different characteristics were the density of pore, the type of xylem ray, the size of xylem ray, etc. Among them, the pore density of C. erythrosticta was the lowest (20~30/cm²), while C. brevipes was the highest (80~100/cm²); the xylem ray types of C. nudiflora were mainly heterogeneous III type, while the other four species were mainly heterogeneous II type. Multiseriate xylem rays of C. brevipes were usually 2 cells wide (rarely 3 cells wide), and the other four species were 2~5 cells wide. The wood structure comparative research with Gmelina chinensis Benth. and Tectona grandis L.f. of the same family indicated that the plants of Callicarpa had certain differences in terms of wood type, pore size, pore density, chord diameter of pore, axial parenchyma, interxylary phloem, number and type of xylem rays. To sum up, there were many similarities in the wood anatomical structures of the five species of Callicarpa L., but there were also significant differences. This research will provide a basis for the wood identification, application, systematic classification and plant conservation of the plants of this Genus.