Daltin Ângela L, Oriani Aline, Scatena Vera L
Departamento de Botânica, Instituto de Biociências, Universidade Estadual Paulista, Rio Claro, SP, Brasil.
An Acad Bras Cienc. 2015 Mar;87(1):157-71. doi: 10.1590/0001-3765201520140071.
The anatomy of leaves and inflorescence axes of Spathanthus (2 spp.), Rapatea (2 spp.), Cephalostemon (1 sp.), and Duckea (1 sp.) (Rapateoideae, Rapateaceae) was studied to identify useful characters for taxonomy. The cross-section shape of inflorescence axis differentiates the genera, while the cross-section shape and structure of leaf midrib has a specific value. The following characteristics are exclusive of Spathanthus: silica cells randomly distributed in the leaf epidermis; plicate chlorenchyma in the leaf blade; presence of fiber bundles in the mesophyll and in the inflorescence axis parenchyma. Spathanthus is also distinguished by the number, type and distribution of vascular bundles in the inflorescence axis. The genus Rapatea is characterized by the presence of stomata and silica cells only on the abaxial epidermis of the leaves and chlorenchyma composed of arm cells in the leaf blade. Characteristics with diagnostic value for Cephalostemon riedelianus are: leaf epidermal cells with straight to slightly sinuous walls in frontal view, inflorescence axes presenting a defined cortex, fiber bundles facing the larger vascular bundles and a fistulous pith. The anatomical characteristics of the leaves and inflorescence axes thus proved to be of taxonomic value in generic and specific levels. They are also useful to differentiate Rapateoideae from other subfamilies of Rapateaceae.
对刺花属（2种）、拟玉荷属（2种）、头蕊草属（1种）和杜氏草属（1种）（玉荷亚科，玉荷科）的叶片和花序轴进行了解剖学研究，以确定有助于分类的特征。花序轴的横截面形状可区分不同属，而叶片中脉的横截面形状和结构具有特定价值。以下特征为刺花属所独有：硅质细胞随机分布于叶片表皮；叶片中有褶状的绿色组织；叶肉和花序轴薄壁组织中有纤维束。刺花属还可通过花序轴中维管束的数量、类型和分布来区分。拟玉荷属的特征是叶片仅下表皮有气孔和硅质细胞，且叶片中的绿色组织由臂状细胞组成。里氏头蕊草具有诊断价值的特征为：叶表皮细胞正面观细胞壁直或微弯，花序轴有明确的皮层，纤维束朝向较大的维管束，髓部中空。因此，叶片和花序轴的解剖特征在属和种的层面上都具有分类学价值。它们也有助于将玉荷亚科与玉荷科的其他亚科区分开来。
