ASPECTS OF PERMIAN PALEOBOTANY AND PALYNOLOGY .18. ON THE MORPHOLOGY AND ULTRASTRUCTURE OF POTONIEISPORITES-NOVICUS (PREPOLLEN OF LATE CARBONIFEROUS EARLY PERMIAN WALCHIACEAE)
Rj. Poort et H. Veld, ASPECTS OF PERMIAN PALEOBOTANY AND PALYNOLOGY .18. ON THE MORPHOLOGY AND ULTRASTRUCTURE OF POTONIEISPORITES-NOVICUS (PREPOLLEN OF LATE CARBONIFEROUS EARLY PERMIAN WALCHIACEAE), Acta botanica neerlandica, 46(2), 1997, pp. 161-173
The type species of the palynological form-genus Potonieisporites, P.
novicus, can be considered to represent Late Carboniferous/Early Permi
an conifers, assignable to the Walchiaceae of the Euramerican floral p
rovince, Morphological and ultrastructural analysis of the species fal
sifies earlier concepts of a monosaccate organization and the presence
of a distal germinal area. The species is characterized by a monosacc
oid sexine expansion, completely filled with an alveolate infrastructu
re. A proximal aperture is distinct: but there is no evidence of dista
l specializations indicative of the outgrowth of a haustorial pollen t
ube; the species thus qualifies as prepollen. These characters are inc
luded in an emended diagnosis for the species. A restricted concept of
an exclusively walchiaceous status for the form-genus Potonieisporite
s can not yet be proposed, mainly because of the lack of conclusive ev
idence on the botanical affinity and the morphological/ultrastructural
organization of similar pollen from the Gondwana floral province.