Geoscience Reference
In-Depth Information
Fig. 3. (a) Calamophyton, Pseudosporochnales. Digitate branch bearing 3D appendages. (b) Calamophyton,
Pseudosporochnales. Detail of branches bearing 3D terminal appendages lacking lamina. (c) Eospermatopteris,
Pseudosporochnales. Swollen base. (d) Pietzschia, Cladoxylopsida. Transverse section of axis showing a ring of radially
elongated primary xylem strands around a very large pith. Small circular strands of primary xylem are also scattered in
the pith. (e) Archaeopteris, Archaeopteridales, lignophytes. Transverse section of axis showing a significant amount of
secondary xylem surrounding the central pith. (f ) Cladoxylon, Cladoxylopsida. Transverse section of axis showing
vascular strands containing radially aligned xylem tracheids compressing the surrounding pith cells (pc: primary
cortex). (g) Xenocladia, Cladoxylopsida. Transverse section of axis showing discrete vascular strands containing
radially aligned tracheids compressing pith cells.
