| Summary: | <i>Tingia</i> Halle, a representative genus of the Cathaysia Flora, has been studied for nearly 100 years, being a small heterosporous tree based on the gross morphology of <i>Tingia unita</i>. However, the systematic affinity of <i>Tingia</i> is uncertain. Now, a number of well-preserved fossils of <i>T. unita</i> from the Taiyuan Formation of Lower Permian in Wuda Coalfield, Wuhai City, Inner Mongolia facilitates an examination of wood anatomy. The stem anatomy of <i>T. unita</i> shows parenchymatous pith, endarch primary xylem, pycnoxylic secondary xylem, and cortex, typically a type of gymnosperm wood, which taken together with pteridophytic reproduction, certainly evidences that <i>Tingia</i> Halle is a progymnosperm. In addition, <i>Tingia</i> together with <i>Paratingia</i> provide strong evidence to link the Noeggerathiales with progymnosperms.
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