Swamp with horsetail trees (Calamites) in the
Northern Zoo in Emmen (NL).
(This diorama does not exist anymore).

Trunk of the horsetail tree Calamites.
Piesberg (Osnabrück, Germ.), Upper Carboniferous
The nodes are characteristic for a horsetail.

Compressed trunk of the horsetail tree Calamites.
Piesberg (Osnabrück, Germany), Upper
Carboniferous. Near to the chisel is a whorl
of leaves. Length of the trunk 2 m.

This is one of the two kinds of leaves of
Calamites: Asterophyllites. The leaves stand
in a whorl oblique to the stem and they are rigid.
Upper Carboniferous. Piesberg (Germany).
Width of the photo 16 cm.

This is the second kind of leaves of Calamites:
Annularia. The leaves are arranged in outspread
whorls and they are less rigid than those of
Asterophyllites. This is Annularia stellata.
Upper Carboniferous. Montceau-les Mines.
Width of the photo 7 cm.

Sphenophyllum oblongifolium.
A herbal horsetail.
Graissessac (Fr), Upper Carboniferous.
Height of the photo 34 cm.