Eusporangiate Fern

Eusporangiate Fern

Eusporangiate ferns are vascular spore plants, whose sporangia arise from several epidermal cells and not from a single cell as in leptosporangiate ferns. Typically these ferns have reduced root systems and sporangia that produce large amounts or spores (up to 7000 spores per sporangium in Christensenia)

There are four extant eusporangiate fern families, distributed among three classes. Each family is assigned to its own order.

  • Class Psilotopsida
    • Order Psilotales, family Psilotaceae – Whisk ferns (2 genera, about 17 species)
    • Order Ophioglossales, family Ophioglossaceae – Adder’s-tongues (5 genera, about 80 species)
  • Class Equisetopsida
    • Order Equisetales, family Equisetaceae – Horsetails (1 genus, about 15 species)
  • Class Marattiopsida
    • Order Marattiales, family Marattiaceae – Marattoid ferns (6 genera, about 500 species)

The following diagram shows a likely phylogenic placement of eusporangiate fern classes within the vascular plants.



lycophytes (club mosses, spike mosses, quillworts)


euphyllophytes

spermatophytes (seed plants)


ferns
Psilotopsida

Psilotales (whisk ferns)



Ophioglossales (grapeferns etc.)



Equisetopsida

Equisetales (horsetails)



Marattiopsida

Marattiales



Polypodiopsida

Osmundales




Hymenophyllales




Gleicheniales




Schizaeales




Salviniales




Cyatheales



Polypodiales











eusporangiate
ferns leptosporangiate
ferns

Read more about Eusporangiate Fern:  Cladistics