Siphonodendron

{{Short description|Extinct genus of corals}}

{{Automatic taxobox

| image_caption = Siphonodendron sp. from Snook Point, Northumberland, UK

| taxon = Siphonodendron

| image = SiphonodendronMcCoy1849.jpg

| authority = McCoy 1849

| subdivision_ranks = Species

| subdivision = †S. irregulare
†S. junceum
†S. martini
†S. pauciradiale
†S. scaleberense

}}

Siphonodendron is an extinct genus of colonial rugose corals common during the Carboniferous period. In fossil form it now appears as a white or brown mass of short spaghetti-like threads, usually flattened during distortion of the embedding limestone. It is in the sub-class Hexacorallia of corals with sixfold symmetry.