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1 Sterile leaves simple, or palmately to pinnately lobed, or 1-4-pinnately divided, the pinnae (or veins) toward the base of the leaf opposite; petioles often inflated; sporangia with or without an annulus, the annulus with 0-10 (-40) indurated cells
1 Sterile leaves (1-) 2-3-pinnately divided, the pinnae toward the base of the leaf alternate; petioles usually not inflated; sporangia with an annulus, the annulus with 13-71 indurated cells.