Geometric morphometrics of corolla shape in Campanula (Campanulaceae) from Cabo Verde archipelago

Abstract

In the Cabo Verde archipelago, Campanula spp. (bellflowers) are currently represented by four endemic species restricted to mountainous islands (C. bravensis, C. feijoana, C. hortelensis and C. jacobaea), all of which are known for high floral polymorphism. Diagnostic features of the corolla often differ from original descriptions, bringing into question their taxonomic delimitation. Based on the variations in the corolla shape observed during fieldwork, eight morphogeographical entities were distinguished among the taxa in the archipelago. Geometric morphometrics was used to quantify and examine these floral variations. Corolla morphology of 221 photographed flowers was captured by 2D landmarks and semi-landmarks configurations and analysed with canonical variate analysis. The results show agreement between morphological groupings and their geographical ranges. For most entities, the geographical origin may be determined with accurate morphological examination of the flower. In this case, the corolla shape proves to be a taxonomically discriminant trait. Furthermore, the terminology used until now to characterize these different floral forms is discussed. The present study contributes significantly to clarifying the floral polymorphism in Cabo Verdean Campanula and suggests that taxonomic revision of this group is necessary.

Model-based plant phenomics on morphological traits using morphometric descriptors

“…Landmark-based morphometrics has been adapted to multiple scales from the inner-cell structure to the whole plant, including grass phytoliths ( Hošková et al 2021 ), leaves ( Silva et al 2012 , Viscosi et al 2009 ), lips of orchid flowers ( Shipunov and Bateman 2005 ), whole flowers ( Gardère et al 2019 , Savriama et al 2012 ), and whole plants ( Manacorda and Asurmendi 2018 ). One of the advantages of landmark-based morphometrics is its applicability to targets whose homology can be defined using shared landmarks among them, even if they consist of multiple elements.…”

Codonographia Gorgonum, or the description of a pleiad of bellflowers (Campanula, Campanulaceae) from the Cabo Verde archipelago

“…To distinguish between these previously unsuspected morphogeographic entities, we recently analysed the corolla shape of all of the CVB using geometric morphometrics (Gardère et al, 2019b). The corolla shapes of 221 photographed flowers were characterized in high detail by placing 2D landmarks and semi-landmarks, and were then subjected to a Generalized Procrustes Analysis to extract shape by removing information on size, location and orientation (Savriama et al, 2012;Gunz & Mitteroecker, 2013;Dryden & Mardia, 2016;Savriama, 2018).…”

Shape Analysis as an Additional Tool in Roe Deer (Capreolus capreolus) Management: A New Approach Based on the Relationship between Mandible Shape and Trophic Resources

“…Therefore, it is not surprising that this approach is becoming very common to quantify anatomical shapes in a wide range of scientific applications, such as animal welfare, human evolution, taxonomy, etc. [6][7][8][9][10][11][12][13][14].…”