Morphometric analysis of Stemodia hyptoides and S. stricta (Plantaginaceae)

SOSA, M. M.; PANSERI, A.; DEMATTEIS, M.

PLANT SYSTEMATICS AND EVOLUTION

SPRINGER WIEN

Lugar: Viena; Año: 2012 vol. 298 p. 1315 - 1323

0378-2697

Stemodia stricta Cham. & Schltdl. has been considered by several authors a synonym of Stemodia hyptoides Cham. & Schltdl., a variety of this taxon or a quite different species of them. These species show a wide morphological variation at inter and intra-specific level, which in some cases it becomes difficult to identify them. In addition, S. hyptoides presents diploid (2n=2x=22), tetraploid (2n=4x=4) and hexaploid (2n=6x=66) cytotypes, while S. stricta is always diploid (2n=22). To determine the taxonomic position and status of both entities, twenty five morpho-anatomical traits were analyzed using multivariate methods. The results show that UPGMA, PCA and DA tests separates the two species and the cytotypes of S. hyptoides in three different groups, which suggests that the analyzed taxa are different morphological and anatomically. The more relevant morphological features to separate the studied specimens are the plant height, leaf size, leaf shape, and corolla length. Stemodia stricta is a good species that be clearly separated from S. hyptoides. The diploid specimens of S. hyptoides may be distinguished from the polyploids by a set of morphological features like shape, pubescence and margin of the leaf and corolla length. The morphological features of the polyploid specimens agree with the original description of S. hyptoides. In consequence the diploid cytotype of S. hyptoides should be considered a different species.