The Hermanophytes are a poorly understood group composed of a single genus of stem fossils, Hermanophyton, from the Late Mesozoic (Tidwell & Ash 1990). The stems are permineralized and usually unbranched with a complex eustelic pattern exhibiting wedge-shaped primary and secondary xylem segments separated by wide primary rays. These plants may have been vines or small trees. Nothing is known about the leaves, roots, or reprodcutive structures of this group.
One genus (Hermanophyton) with four species (Tidwell & Ash 1990)
H. taylorii
H. glismannii (Tidwell & Ash 1990)
An enigmatic group with unknown affinities
They have attributed to Corystospermales, Cycads, Medullosales, Pentoxylales, Bennettitales
Maybe vine-like or short- to medium-sized narrow-stemmed tree
Known from permineralized stems (Hermanophyton)
Usually unbranched, 3-40 cm wide (Tidwell 2002)
Complex anatomy
Pith with parenchyma
Wedge-shaped primary and secondary xylem segments separated by wide primary rays
10 m long specimen had a consistent diameter of 12 cm which may indicate a vine-like habit
Unknown
Unknown
Unknown
└? Hermanophytes †
Southwestern USA & Europe