J Syst Evol

• Research Articles •    

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

Bao Nie1,2, Bo‐Han Jiao1,2, Li‐Fei Ren1, Polina D. Gudkova3,4, Wen‐Li Chen5, and Wen‐Hao Zhang1,2*   

  1. 1 State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
    2 College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
    3 Research Laboratory “Herbarium”, National Research Tomsk State University, Tomsk 634050, Russia
    4 Faculty of Biology, Altai State University, Barnaul 656049, Russia
    5 State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
  • Received:2020-07-30 Accepted:2020-11-23 Online:2020-12-07

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.

Key words: common garden experiment, cryptic species, ecological divergence, phenotypic plasticity, Stipa