Placental morphology helps to analyse pteridophyte ancestry
Highly distinctive gametophyte/sporophyte junctions in leptosporangiate ferns are characterized by sporophytic haustoria, wall ingrowths in both generations, mitochondrial aggregations in the gametophyte and large amyloplasts in the sporophyte. Duckett and Ligrone (pp. 513-521) investigate how major differences between the placentas of ferns and lycophytes reinforce the notion of two major pteridophyte lineages based on morphological and molecular data.
