A tiny elongated structure that forces the dispersal of spores by the absorption of moisture.It is either a band attached to the spore, as in horsetails, or a filament occurring among the spores, as in liverworts.

• 弹丝一条小长丝结构，通过吸收水分促使孢子分裂。可以是连接到孢子上的一个丝圈，如长在杉叶藻内的，也可以是各孢子间的一条长丝，如在苔藓内的