Fruits of neotropical species of the tribe Malveae (Malvoideae - Malvaceae): macro- and micromorphology

ABSTRACT Fruit morphology of the tribe Malveae has been discussed since the first taxonomic classifications of Malvaceae. The fruits are schizocarps, with some genera possessing an endoglossum. Besides morphological variation in the endoglossum, other differences include the number seeds per locule and ornamentation of the exocarp. An in-depth study of the fruit morphology of Malveae is essential to gain insight into the relationships among taxa of the tribe. Therefore, the present study aimed to describe the fruit morphology of Malveae, including micromorphology, variation in endoglossum structure and arrangement of seeds in the locule, to comprehensively evaluate the systematic relationships among its contained taxa. The results indicate morphological variation in fruit of various genera with regard to the number of mericarps, degree of dehiscence, relationship between calyx and fruit and their relative sizes, number and morphology of spines, number of seeds per locule, presence or absence of an endoglossum, presence and types of trichomes in exocarp and endocarp, and shape and presence of trichomes in the testa of seeds. Despite the morphological proximity of taxa, there are distinct combinations of characters that define some genera, and when one or more characters overlap, joint analysis makes it possible to clarify existing relationships.

摘要 锦葵族（Malveae）的果实形态自锦葵科（Malvaceae）首次开展分类学研究以来便已得到广泛讨论。该族植物的果实为分果（schizocarp），部分属类具有内舌（endoglossum）结构。除内舌自身的形态变异外，其他分类学差异还包括每子房室（locule）的种子数量以及外果皮（exocarp）的纹饰特征。深入探究锦葵族的果实形态，对于阐明该族类群间的系统演化关系至关重要。为此，本研究旨在系统描述锦葵族的果实形态，涵盖显微形态特征、内舌结构的变异类型以及子房室内的种子排布方式，以全面评估其所含类群的系统亲缘关系。研究结果表明，不同属的果实存在多维度的形态变异，具体包括分果瓣（mericarp）数量、果实开裂程度、花萼与果实的关联模式及相对大小、刺的数量与形态、每子房室的种子数、内舌的有无、内外果皮的毛状体（trichomes）类型与存在情况，以及种子种皮（testa）的形态特征与毛状体分布。尽管该族类群在整体形态上较为相近，但部分类群可通过独特的性状组合加以区分；当单个或多个性状出现重叠时，联合性状分析可有效厘清现存的系统发育关系。