Calamostachys ramosa, the spore cone of a horsetail, in a siderite nodule.
Crockhey, Westphalian A. Width of the photo is 6 cm.
Calamostachys ramosa, the spore cone of a horsetail, in a siderite
nodule.
Crockhey, Westphalian A. Width of the photo is 6 cm.