1 The major morphology of Pteridium spp.: (a) frond lamina (blade); (b) rachis; (c) pinna; (d) stipe; (e) nectary; (f) crozier with hairs; (g) leaf primordium on short-shoot; (h) apex of shoot; (i) lateral line; (j) petiolar roots (in P. esculentum); (k) roots; (l) rhizome; (m to p) pinna; with (m) pinnule; (n) midrib of pinna; (o) pinnulet; and (p) midrib of pinnule; (q) lower surface of pinnule; (r to w) section of the margin of pinnulet; with (r) upper surface; (s) lower surface; (t) mature sporangium; (u) indusium; (v) sporangium after discharge of spores; (w) false indusium; (y to z) shows (x) frond primordium; (y) abaxial bud and (z) adaxial bud. Redrawn by author from Marrs and Watt (2006)