Calamostachys sp., the spore cone of a horsetail, in a siderite nodule.
The sporangia are visible as dark spots between the scales.
Crockhey, Westphalian A. Width of the photo is 10.5 cm.
Calamostachys sp., the spore cone of a horsetail, in a
siderite nodule.
The sporangia are visible as dark spots between the scales.
Crockhey, Westphalian A. Width of the photo is 10.5 cm.