Integrative taxonomy recognized a new cryptic species within Stipa grandis from Loess Plateau of China

Abstract

Stipa shanxiensis, a cryptic species within Stipa grandis that originated from central and western China, is described based on morphological, genomic, and ecological data from field and common garden experiments. Stipa shanxiensis morphologically resembles S. grandis, although phylogenetically it is closely related to the less morphologically similar Stipa baicalensis and Stipa krylovii. Of the eight significant morphological differences between S. shanxiensis and S. grandis, the two, cauline ligules longer than 2 cm with a filiform apex, and hairs shorter than 0.2 mm on the adaxial surface of the cauline uppermost leaves can be used to distinguish the species. Results from a common garden experiment verified that the two diagnostic characteristics were relatively stable and less morphologically plastic in response to environmental variation. Furthermore, a significant ecological divergence was found between S. shanxiensis and S. grandis, such that the former preferred warmer and more humid climates, and their predicted distribution was generally separated. Taken together, our results highlight that the integrative taxonomic approach was valuable for recognizing a new cryptic species in Stipa. In particular, we find that common garden experiments involving the effects of growth stage and characteristic position helped to morphologically diagnose cryptic species. These findings may also facilitate our understandings of ecological adaption and phenotypic plasticity in response to environmental change.

Pinellia discolor: a new cryptic species distinguished from P. cordata in mainland China

“…4, Supporting information). This pattern of distribution shown by P. cordata and P. discolor is similar to that of Stipa shanxiensis and Stipa grandis (Poaceae; Nie et al 2022).…”

Resurrection of Stipa tremula and taxonomy of the high-alpine species from the Stipa purpurea complex (Poaceae, Pooideae)

“…These characters may suggest that the taxon originated from hybridisation between S. tremula and S. purpurea , whereas the presence of such long florets (longer than in both putative parental species) may be a result of genome duplication, which sometimes happens in hybrids and is called as the Gigas effect ( Stebbins 1971 ; Levin and Donald 2002 ; Soltis et al 2014 ; Meeus et al 2020 ). Nevertheless, the putative hybrid origin of S. arenosa requires confirmation using karyological and integrative morpho-molecular methods, such as those used recently to confirm the origin of other hybrids and cryptic taxa of feathergrasses ( Nobis et al 2019c ; Baiakhmetov et al 2020 , 2021 ; Nie et al 2020 ; Tkach et al 2021 ).…”

Hybridization and introgression events in cooccurring populations of closely related grasses (Poaceae: Stipa) in high mountain steppes of Central Asia

“…Due to many examples of hybrids that occur in Poaceae, including intergeneric hybrids such as the wheat-grass cross of Triticum × Agropyron [25,26], Oryzopsis × Stipa [27], Dendrocalamus × Gigantochloa [28], and intrageneric hybrids such as in Elymus [7,29,30], Andropogon [31], Elytrigia [32], Arundinaria [33], Poa [34] and Austrostipa [35], therefore the family constitute an excellent example for research on the role of interspecific hybridization [36][37][38][39]. Along with the previously mentioned examples, Stipa is one of the genera with over 150 species found in warm temperate regions of Europe, Asia, and North Africa [40][41][42], with approximately 30% of hybrid origin taxa [40]. The majority of hybrid identifications in Stipa (e.g.…”