Leaf teeth are projections on the leaf blade margin. They are structurally variable, with characters that are important for taxonomy and phylogeny, but there is a paucity of information on the anatomy of these structures and little understanding of the features and their functions. Here we describe and compare the leaf tooth anatomy of 47 eudicot species. Toothed margin samples from leaves at different developmental stages were collected, fixed and studied under light and scanning electron microscopy. We identified eight leaf tooth morphotypes, six of which occurred with glands. Hydathodes were the most common glands, being found in 11 species; colleters were found in ten species and extrafloral nectaries were found in two species. Cunonioid teeth either devoid of glands or associated with hydathodes were found in Lamiales, Asterales and Apiales. Dillenioid teeth associated with hydathodes were found in Dilleniales. Spinose teeth associated with colleters were found in Aquifoliales. In rosids, we found begonioid, malvoid, theoid, urticoid and violoid teeth, which may be associated with either colleters or nectaries or lack an associated gland. For each family studied, there was only one type of association between gland and tooth, demonstrating the systematic potential of these glands in eudicots.

中文翻译：

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双子叶植物的牙齿：解剖学可以阐明什么？

叶齿是叶片边缘上的突起。它们在结构上是可变的，具有对于分类学和系统发育很重要的特征，但是关于这些结构的解剖结构的信息很少，对特征和功能的了解很少。在这里，我们描述并比较了47种双子叶植物的叶齿解剖结构。收集，固定并在光和扫描电子显微镜下研究来自不同发育阶段的叶片的齿状边缘样品。我们鉴定出八种叶齿形态，其中六种与腺体有关。Hydathodes是最常见的腺体，共发现11种。在十个物种中发现了let本，在两个物种中发现了花外蜜腺。在Lamiales，Asterales和Apiales中发现了没有腺体或与hydrothodes有关的类杜鹃牙齿。在Dilleniales中发现了与hydrathodes有关的Dillenioid牙齿。在Aquifoliales中发现了与筒夹相关的棘齿。在蔷薇类中，我们发现了似雌性，性腺无力，类齿，荨麻疹和类静脉瘤的牙齿，这些牙齿可能与筒子或蜜腺有关，或者缺少相关的腺体。对于每个研究的家庭，腺体和牙齿之间只有一种关联类型，表明这些腺体在双子叶植物中的系统潜力。