Assertion: woody plant's stem | /r/HasProperty | assigned to either calamites
Facets:
Source sentences:
text: For instance, in the subarborescent Palaeozoic sphenophytes, an impression of a leaf might be assigned to the genus Annularia, a compression of a cone assigned to Palaeostachya, and the stem assigned to either Calamites or Arthroxylon depending on whether it is preserved as a cast or a petrifaction.