Ferns of St. Louis

In the St. Louis Area, we have 38 not-too-obscure ferns. The PPG (Pteridophyte Phylogeny Group) now places the ferns under a big umbrella class called “POLYPODIOPSIDA”. This big class (which includes the horsetails) is divided into 4 subclasses. We’re lucky to have 3 of these subclasses here in St. Louis:

Subclass EQUISETIDAE (the Horsetails):

• Equisetum arvense – Field Horsetail (Equisetales)
• Equisetum laevigatum – Smooth Horsetail (Equisetales)
  (more commonly found on the Illinois side)
• Equisetum hyemale – Tall Horsetail (Equisetales)
  (there’s also a sterile hybrid cross between E. laevigatum and E. hyemale called “Intermediate Horestail” [Equisetum x ferrissii] which makes identification challenging)

Subclass OPHIOGLOSSIDAE (the Eusporangiate Ferns):

• Botrypus virginianus – Rattlesnake fern (Ophioglossales)
• Ophioglossum engelmannii – Limestone Adder’s tongue fern (Ophioglossales)
• Ophioglossum vulgatum – Southern Adder’s tongue fern (Ophioglossales)
• Sceptridium dissectum – Cut Leaved Grape Fern, Bronze Fern (Ophioglossales)

Subclass POLYPODIIDAE (the Leptosporangiate Ferns):

• Adiantum pedatum – Maidenhair fern – habitat: moist shade (Polypodiales)
• Asplenium bradleyi – Bradley’s spleenwort – habitat: sheltered dry (Polypodiales)
• Asplenium ebenoides – Scott’s spleenwort (Polypodiales)
• Asplenium platyneuron – Ebony spleenwort – habitat: moist or dry (Polypodiales)
• Asplenium resiliens – Black stem spleenwort – habitat: dry (Polypodiales)
• Asplenium rhizophyllum – Walking fern (Polypodiales)
• Asplenium ruta-murania – Wall rue spleenwort (Polypodiales)
• Asplenium trichomanes – Maidenhair spleenwort – habitat: moist (Polypodiales)
• Athyrium angustum – Northern Lady fern – habitat: moist (Polypodiales)
• Athyrium asplenioides – Southern Lady Fern (Polypodiales)
• Cystopteris bulbifera – Bulblet fern – habitat: damp (Polypodiales)
• Cystopteris protrusa – Fragile fern – habitat: moist – rooted in soil (Polypodiales)
• Cystopteris tennesseensis – Tennessee bladder fern – habitat: moist (Polypodiales)
• Deparia acrostichoides – Silvery spleenwort (Polypodiales)
• Dryopteris marginalis – Marginal shield fern (Polypodiales)
• Homalosorus pycnocarpos – Glade Fern (Polypodiales)
• Myriopteris gracilis – Slender Lip Fern or Fee’s Lip Fern (Polypodiales)
• Myriopteris lanosa – Hairy lip fern (Polypodiales)
• Onoclea sensibilis – Sensitive fern (Polypodiales)
• Pellaea atropurpurea – Purple cliffbrake – habitat: limestone or sandstone (Polypodiales)
• Pellaea glabella – Smooth cliff brake (Polypodiales)
• Phegopteris hexagonoptera – Broad beech fern (Polypodiales)
• Pleopeltis polypodioides – Resurrection fen (Polypodiales)
• Polypodium virginianum – Common polypody (Polypodiales)
• Polystichum acrostichoides – Christmas fern – habitat: moist or dry (Polypodiales)
• Pteridium aquilinum – Bracken fern (Polypodiales)
• Thelypteris palustris – Marsh fern – habitat: constant moisture, acid or alkaline (Polypodiales)
• Woodsia obtusa – Blunt-Lobed Cliff Fern – habitat: moist or dry (Polypodiales)

These 3 ferns, although in the same Polypodiidae subclass, are in a different order:

• Osmunda claytoniana – Interrupted fern – habitat: moist sandstone (Osmundales)
• Osmunda spectabilis – Royal fern – habitat: moist sandstone (Osmundales)
• Osmundastrum cinnamomeum – Cinnamon fern – habitat: moist sandstone (Osmundales)

*habitat notes kindly provided by Kathy Bildner
*distribution maps provided by BONAP