Reconstructing the Architecture and Growth Habit ofPietzschia levissp. nov. (Cladoxylopsida) from the Late Devonian of Southeastern Morocco

Abstract

Pietzschia levis sp. nov. is represented by a 40‐cm‐long, anatomically preserved stem discovered in the locality of Mader el Mrakib, dated as Early Famennian by the associated marine fauna. Its assignment to the genus Pietzschia is based on the following characters: a dissected primary vascular system comprising a ring of discrete, radiating xylem plates encircling numerous smaller bundles; a large pith; several protoxylem poles in peripheral xylem plates that are not associated with parenchyma; sclerenchyma plates alternating with the peripheral xylem plates; absence of secondary tissues; and traces to lateral organs in groups, departing from more than two peripheral xylem plates. Anatomical characters that are unique to the new species are extensive aerenchymatous tissues occurring within the stem and bases of lateral organs; the small amount of vascular tissues; and the large number of peripheral xylem plates involved in emission of traces. The first two characters indicate ecological preferences of ou...