Disentangling leaf morphology in Daustinia montana (Convolvulaceae)

Daustinia montana (Convolvulaceae) is the only species of the genus, and is notable for its wide leaf variability. To understand whether this plasticity is correlated with the distribution of the species, linear morphometric and leaf contour analyses were performed. Specimens from herbaria were photographed, and pre-established linear measurements were made. A multivariate analysis was then performed to test the strength of associations among morphological characteristics, climatic variables, and distribution of the species. Elliptic Fourier analysis based on 20 harmonics was used to generate shape descriptors, resulting in nine main components. With elliptic Fourier descriptors, a grouping tree was created that suggests the existence of six morphotypes in D. montana. Moreover, clustering analysis revealed two large groups distinguished mainly by leaf width. The present findings indicate that the morphotypes are strongly related to latitude and that other characteristics such as the typ...

山地道斯廷尼亚藤（Daustinia montana，旋花科Convolvulaceae）为该单型属的唯一物种，其叶片变异幅度之大尤为引人注目。为探究该物种的叶片表型可塑性是否与其分布格局相关，本研究开展了线性形态计量学与叶片轮廓分析。研究人员对标本馆馆藏标本进行拍照，并完成了预设的线性形态测量。随后通过多变量分析，检验形态特征、气候变量与物种分布三者间的关联强度。基于20次谐波的椭圆傅里叶分析（Elliptic Fourier Analysis）用于生成形状描述符，最终提取得到9个主成分。依托椭圆傅里叶描述符，研究构建了聚类树，结果表明山地道斯廷尼亚藤存在6种形态型（morphotypes）。此外，聚类分析还揭示出两大类群，二者的主要区分依据为叶片宽度。本研究结果显示，形态型与纬度呈显著相关，而叶片宽度等其他特征如……