Calamites-trees had horizontally growing stems in the soil,
called rhizomes, from which new vertical axes sprang.
The pith of a new stem was funnel-shaped at the attachment.
Often the cavities have been filled up with sediment and then fossilized.
Pith cast of a rhizome with offshoot and some visible roots
Eygelshoven
Westfalian A/B
Length of the rhizome 19 cms.