Osmundastrum C.Presl, Gefässbündel Farrn

Kessler, Michael & Smith, Alan R., 2017, Prodromus of a fern flora for Bolivia. IX. Osmundaceae, Phytotaxa 327 (1), pp. 100-102 : 101

Osmundastrum C.Presl, Gefässbündel Farrn 18. 1847.

A monospecific genus that was formerly included in Osmunda but is now segregated based on molecular evidence that shows it to be sister to the remainder of the family ( Yatabe et al. 1999, Metzgar et al. 2008). This taxonomy is also supported by anatomical traits ( Hewitson 1962, Miller 1971). Osmundastrum is distinguished by pinnate-pinnatifid leaf dissection, dimorphic leaves with contracted fertile blades, tufts of hairs abaxially on photosynthetic blades near the junction of the pinnae with the rachis, and reddish brown hairs on petioles ( Metzgar et al. 2008).