rough horsetail (equisetum hyemale). strobilus closeup

equisetaceae equisetum hyemale cone fused leaf base groove sheath longitudinal monomorphic node ridge rough horsetail scouring rush scalelike silica tubercle stem strobilus whorl strobil hyemale closeup virtual herbarium belarus flora: focus-stacked closeups wild cultivated plants including flowers leaves fruits intended illustrations botanical manuals