Psilotaceae
- Description and illustration of anatomical structure of species in Hawaii
- http://www.botany.hawaii.edu/faculty/webb/BOT201/PSILOTUM/psilotum2.htm

Psilophyta
- Profusely illustrated description focussed on morphology and evolution.
- http://www.botany.hawaii.edu/faculty/webb/BOT201/PSILOTUM/Psilophyta-1.htm

Introduction to the Psilotales
- Includes descriptions of morphology and life history.
- http://www.ucmp.berkeley.edu/plants/pterophyta/psilotales.html

Fork Ferns
- Illustrated introduction to the five species of Psilotaceae found in New Zealand.
- http://www.hiddenforest.co.nz/plants/forkferns/forkferns.htm

Classification of Psilotophyta
- Main entry in Systema Naturae 2000.
- http://sn2000.taxonomy.nl/Main/Classification/95997.htm

Division Psilotophyta
- Description with links to images of Psilotum nudum and Tmesipteris tannensis.
- http://www.esu.edu/~milewski/intro_biol_two/lab_2_moss_ferns/Psilophyta.html

Phylum Psilophyta
- Includes phylum description, and links to images of members of the Psilotaceae.
- http://www.science.siu.edu/landplants/Psilophyta/psilophyta.html