Study on the spore release of Polytrichum commune Hedw. var. commune by synergetic effects of sub‐hygroscopic movement and wind

• The effect of humidity change on the spore release of the nematodontae Polytrichaceae plants has never been tested experimentally. Similarly, the impact of humidity alteration on the structure of peristome has never been studied. • The Polytrichum commune Hedw. var. commune from Guizhou Province in China was selected as the research object, about which the simulated wind blowing experiment was carried out in the laboratory. By controlling the humidity and wind, the mechanism of spore disperse was revealed. • The experiments demonstrate that (1) When the humidity increase, the size of peristome structure and epiphragm enlarge significantly (the peristome has no obvious spatial displacement, which is different from the hygroscopic movement of the arthrodontae mosses. Thus, we call it "sub-hygroscopic movement"), and then recover to the normal size when the humidity dries again. (2) Regulated the humidity of the capsule in the wind, the scatter of the spores gradually decreases with the capsule dried out and finally keeps at a very low level; when the capsule wetted or rewetted once again, the amount of spores rises obviously at the initial stage. (3) Through the comparison of moist capsule and dry capsule, it is found that only by enhancing the humidity of the sporophytes, the release of spores is apparently increased. • Results show that the dispersion of spores was significantly improved under the cooperation of wind and sub-hygroscopic movement of capsule peristome, which ensured the continuity and effectiveness of the Polytrichum commune Hedw. var. commune reproduction.