Abstract

Putranjivaceae are a pantropically distributed but poorly known glucosinulate-producing family of three genera (Drypetes, Putranjiva and Sibangea), previously included in Euphorbiaceae subfamily Phyllanthoideae. Characters of the leaf epidermis were previously suggested as being of infrafamilial taxonomic relevance, but epidermal features of the three genera have not so far been compared in the light of the phylogenetic relationships recovered by molecular data. Therefore, we compared the leaf micromorphology of 44 (out of c. 200) Drypetes spp. and two (out of three) Putranjiva spp. using light microscopy. Our findings revealed that there are more stomata types than previously reported in both genera. We also present a new record of stomatal complexes and epidermal cell characteristics. The cell wall ornamentation character on both surfaces of the epidermis is useful for distinguishing D. aframensis subsp. aframensis. Based on a combination of the studied characters, doubtful species of Drypetes and Putranjiva are recognizable as belonging to the two genera, and this will require taxonomic and nomenclatural adjustments. Other taxonomically useful characters are trichome distribution and types and leaf areole shape and tertiary veins branching patterns that appear to be relatively constant across the two genera. Oil droplets located within the cell lumen in Putranjiva differentiates it from Drypetes, where they inwardly streak the epidermal walls among other features. Thus, our study provides evidence that the investigated leaf micromorphological characters are useful for distinguishing the species of the two genera, and they corroborate the existing infrageneric classification of Drypetes that was based on exomorphology.

中文翻译：

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Drypetes和Putranjiva（Putranjivaceae）的叶片微观形态比较及其分类学意义

摘要

Putranjivaceae是一个泛热分布的，但鲜为人知的三个属（Drypetes，Putranjiva和Sibangea）的产生葡萄糖苷的家族，以前属于大戟科亚科Phyllanthoideae。先前认为叶表皮的特征与家族内分类学相关，但是根据分子数据恢复的系统发育关系，至今尚未比较这三个属的表皮特征。因此，我们比较了44叶片微（满分Ç。200）Drypetes属。和两个（三个）Putranjivaspp。使用光学显微镜。我们的发现表明，两个属中的气孔类型比以前报告的要多。我们还提出了气孔复合物和表皮细胞特征的新记录。表皮的两个表面上的细胞壁装饰特征对于区分D. aframensis亚种是有用的。frame虫病。根据所研究的人物，令人怀疑种的组合Drypetes和Putranjiva可以识别为属于这两个属，这需要分类和命名上的调整。其他在分类学上有用的特征是毛状体的分布和类型以及叶片的异戊二烯形状和第三脉分支模式，在这两个属上似乎相对恒定。位于Putranjiva细胞内腔中的油滴将其与Drypetes区别开来，Drypetes向内剥落表皮壁以及其他特征。因此，我们的研究提供的证据表明，被调查的叶微形态特征是用于区分两个属的种有用的，他们证实现有属下分类Drypetes这是基于exomorphology。