Lyginopteris

{{short description|Extinct genus of Late Carboniferous seed ferns}}

{{Automatic taxobox

| fossil_range = {{fossil range|Late Carboniferous}}

| image = Lyginopteris oldhamiana.jpg

| image_caption = Permineralized stem Lyginopteris oldhamiana from coal ball of Late Carboniferous Six Inch Coal in Hough Hill Colliery near Stalybridge, England

| taxon = Lyginopteris

| authority = (Binney) Potonie 1899

| subdivision_ranks = Species

| subdivision =

• Lyginopteris austriaca
• Lyginopteris heterangeoides
• Lyginopteris lacunosa
• Lyginopteris oldhamiana
• Lyginopteris royalii

}}

Lyginopteris is a genus of Late Carboniferous seed fern stems with a very distinctive outer cortex of sclereids forming a pattern in cross section like Roman numerals on a clock face, often called a Sparganum cortex. Some Lyginopteris were parasitized by water molds, such as the Combresomyces.{{Cite journal|last1=Strullu-Derrien|first1=C.|last2=Kenrick|first2=P.|last3=Rioult|first3=J. P.|last4=Strullu|first4=D. G.|year=2010|title=Evidence of parasitic Oomycetes (Peronosporomycetes) infecting the stem cortex of the Carboniferous seed fern Lyginopteris oldhamia|journal=Proceedings of the Royal Society B: Biological Sciences|volume=278|issue=1706|pages=675–680|doi=10.1098/rspb.2010.1603|pmc=3030852|pmid=20843846}}