Pseudobornia †

Ecology & Form

• Vegetative features similar to Equisetales; Reproductive parts are similar to the Sphenophyllales

Stems

• Distinct nodes and internodes

  • Basal nodes produce 1-2 first-order branches up to 3 m long

  • Second-order branches are opposite and decussate

  • Higher-order branches emerge in pseudo-distichous pattern

• Pseudomonopodial or monopodial branching

  • 15-20 meters tall

• Anatomy is unknown

Leaves

• Originally called meiophylls

• Produced only on high-order branches

• Highly dissected leaflet attached to twice-dichotomous petiole

Roots

• Underground portions unknown

Reproduction

• Fertile branches up to 30 cm long

• Each fertile unit exhibits whorled bracts and sporangiophores

  • Sporangiophores have upturned tips divided into two segments

  • Each sporangiophore has ~30 sporangia