Fig. 1

Morphologies of sporangia during plant development. a An early stage of kidney-shaped sporangia developed from the auxiliary side of leaves in the late April; b–j morphologies of growing sporangia in the middle May (b), the early June (c), the early July (d), the late August (e), the middle September (f), the middle October (g), the middle November (h), the middle December (i), the late January of the next year (j); k, l the residues of sporangia after spores detach. Bar 12 mm in a, h, i, and l; bar 8 mm in b, c, e, and g; bar 6 mm in f, g, and k; bar 5 mm in d