Sympetaly is a notable feature within the mimosoid clade (Leguminosae: Caesalpinioideae), specially as it is uncommon in rosids. The way the petals are organized, forming a tubular corolla by the union of the petals directly affects the perception of pollinators. This study examines whether the petal union leading to a sympetalous corolla in the mimosoid clade is widespread and whether there is variation in type and extent. For this purpose, floral buds and flowers of 16 species from 13 genera were collected, fixed, and processed for analysis by light and scanning electron microscopy. Most species studied display a pentamerous sympetalous corolla with free lobes. The petal primordia are individualized and emerge simultaneously on the floral apex, alternating with the sepal primordia. Petals remain free at the beginning of the intermediate stages of development, and subsequently, the petals curve and approach each other, and their margins touch. Epidermal papillae are found on the petals’ apical margin interconnecting the lobes, which enclose the inner organs of the floral bud. The structure of the sympetalous corolla is variable regarding the type and extent of the union. Four different types of sympetaly were found and classified as follows: 1. full connation - petals fully united along their length; 2. connation-coherence - petals genuinely united in the basal portion and coherent in the median and apical portion; 3. full coherence - petals intertwined with papillae throughout; and 4. partial coherence - free petals at the base and intertwined with papillae in the middle and apical portion. Thus, sympetaly of mimosoid legumes results from postgenital union of the petals at the apical, median, and basal regions during their development by tissue union (connation), intertwining of epidermal papillae (coherence), or both processes. The mucilage cells found along the petals guarantee the stabilization and flexibility of the tubes, in addition to contributing to the protection of the internal organs of the flower. Although more studies on floral development are needed to understand the evolution of this unusual trait, connation appears to be a derived trait within mimosoids.

Sympetaly 是含羞草进化枝（豆科：Caesalpinioideae）中的一个显着特征，特别是因为它在蔷薇科植物中并不常见。花瓣的组织方式，通过花瓣的结合形成管状花冠，直接影响传粉者的感知。这项研究检查了含羞草进化枝中导致同花冠的花瓣结合是否广泛存在，以及类型和范围是否存在差异。为此，收集、固定和处理了 13 个属的 16 个物种的花蕾和花，以用于光学和扫描电子显微镜分析。研究的大多数物种都展示了带有自由裂片的五瓣同瓣花冠。花瓣原基个体化并同时出现在花的顶端，与萼片原基交替。花瓣在发育的中间阶段开始时保持自由，随后，花瓣弯曲并相互靠近，并且它们的边缘接触。表皮乳突位于花瓣的顶端边缘，连接裂片，包围花芽的内部器官。同瓣花冠的结构因结合的类型和范围而异。共发现了四种不同类型的合瓣花，分类如下： 1. 完整的合生花瓣 - 花瓣沿其长度完全合在一起；2. 连续连贯——花瓣基部真正合一，中部和顶端连贯；3. 完全连贯——花瓣与乳突贯穿始终；和 4。部分连贯 - 基部无花瓣，中间和顶端部分与乳突交织在一起。因此，含羞草豆科植物的共瓣是由花瓣在其发育过程中通过组织结合（connation）、表皮乳突交织（连贯性）或这两个过程在顶端、中部和基部区域的后生殖结合引起的。沿着花瓣发现的粘液细胞除了有助于保护花朵的内部器官外，还保证了管子的稳定性和柔韧性。虽然更多的研究关于 或两个过程。沿着花瓣发现的粘液细胞除了有助于保护花朵的内部器官外，还保证了管子的稳定性和柔韧性。虽然更多的研究关于 或两个过程。沿着花瓣发现的粘液细胞除了有助于保护花朵的内部器官外，还保证了管子的稳定性和柔韧性。虽然更多的研究关于了解这种不寻常性状的进化需要花的发育，连接似乎是含羞草中的衍生性状。