Morphological Studies on Seeds of Scrophulariaceae s.l. and Their Systematic Significance

Abstract

This study employed scanning electron microscopy and light microscopy to observe seed surface micromorphology and seed coat anatomy in the Scrophulariaceae s.l. to investigate seed characters of taxonomic importance. Seeds of 41 taxa corresponding to 13 genera of the family were carefully investigated. Seeds were minute and less than or slightly larger than 1 millimeter in length except for Melampyrum and Pedicularis species. The seed shape ranged from elliptical to broad elliptical and ovoid. In the studied species the surface sculpture was predominantly reticulate-striate, regular reticulate, sometimes colliculate, and rugose, or-rarely-ribbed, as in Lindernia procumbens and Paulownia coreana. Seed coats comprised the epidermis and the endothelium. Nevertheless, in all Melampyrum and some Veronica species the seed coat was very poorly represented and only formed by a papery layer of epidermis. According to correspondence analysis (CA) and unweighted pair group method with arithmetic mean (UPGMA) based cluster analysis the close affinities among the species of Scrophularia were well supported by their proximity to one another. Similarly, the proximity of Melampyrum species and Pedicularis species cannot be denied. In contrast, Veronica species were divided into two groups in CA plots and even three in the UPGMA tree. Regardless of the limited range taxa considered we found that similarities and differences in seed morphology between different genera could help us to understand the systematic relationships involved.

Taxonomic Significance of Seed Morphology in Veronica L. (Plantaginaceae) Species from Central Europe

“…The seeds were medium-sized, cochlidiospermous, with a deeply transversely wrinkled dorsal seed surface and a generally radially wrinkled ventral side. These features were observed, e.g., by Kulpa [ 29 ] and Ghimire et al [ 37 ], and confirmed in the present study. The seed coat was reticulate-verrucate [ 25 ].…”

“…In our analyses, V. peregrina and V. serpyllifolia differed from the remaining species of the subgenus by the reticulate-verrucate type of the testa surface, but this type was characteristic of many subgenera and former sections, including Pocilla and Veronicastrum [ 30 ]. The specific feature of V. peregrina was the keel on the dorsal side of the seed, observed also by other authors [ 25 , 29 , 31 , 37 ]. The strongly flattened seeds were one of the important characteristics of the group delimited by Kulpa [ 29 ], and comprising V. peregrina and V. serpyllifolia .…”

The known, unknown, and the intriguing about members of a critically endangered traditional medicinal plant genus Aconitum

“…Seed morphology has been acknowledged as a significant source of valuable phylogenetic information due to its high consistency. The seed morphology of several angiosperm taxa has already been thoroughly examined (Oh et al, 2008;Mundhra and Roy, 2012;Ghimire et al, 2017), along with phenetic or phylogenetic analysis at the genus level. The variance in seed morphology has previously been utilized in plant systematics in various ways -character-state evolution, phylogenetic inference, and taxonomy circumscription (Ghimire et al, 2017).…”

“…The seed morphology of several angiosperm taxa has already been thoroughly examined (Oh et al, 2008;Mundhra and Roy, 2012;Ghimire et al, 2017), along with phenetic or phylogenetic analysis at the genus level. The variance in seed morphology has previously been utilized in plant systematics in various ways -character-state evolution, phylogenetic inference, and taxonomy circumscription (Ghimire et al, 2017). Macro-and micromorphological seed traits within and among the various genera serve as valuable taxonomic evidence that aids in classifying taxa (Fawzi, 2011;Patil et al, 2015).…”