Microstructure and tensile properties of leaves of six Carex species

Carex leaves provide high-quality natural fiber. Studying the tensile properties and microstructure of Carex leaves can provide a theoretical basis for understanding the development and use of Carex leaves. In this study, the leaves of six species of Carex were taken as the object, their mechanical properties were tested with an electronic tensile testing machine, the microstructure was observed via the paraffin section method, and the relationship between mechanical properties and microstructure was analyzed. The maximum tension and elastic modulus were found in the decreasing order of C. arnellii > C. leiorhyncha > C. lanceolata > C. meyeriana > C. humilis > C. callitrichos var. nana; the tensile strength was in the decreasing order of C. humilis > C. callitrichos var. nana > C. leiorhyncha > C. arnellii > C. meyeriana > C. lanceolate. All the six species of Carex had isolateral leaves, and the leaves were composed of epidermis, basic parenchyma, sclerenchyma, and vascular bundles. The maximum tension and elastic modulus were positively correlated with the number of vascular bundles, thickness, and layers of the sclerenchyma cells (P < 0.01). A significant positive correlation was found between the tensile strength and vascular bundle density of leaves ( P < 0.01). In conclusion, the number of vascular bundles and the degree of thick-walled mechanical structure are important factors determining the maximum tensile strength and elastic modulus of the leaves of six Carexspp. vascular bundle density is an important factor determining the tensile strength of the leaves of six Carexspp. The tensile strength of C. humilis was the highest, and the deformation resistance of C. arnellii was the strongest. In future studies of Carexspp., these findings should be further integrated with other related morphological, physiological, and biochemical indicators to lay a foundation for future screening and adaptability research on Carex plants.