Image is a cross-section of Psilotum nudum, from Plant Microtechnique (1940), p382. https://archive.org/details/in.ernet.dli.2015.29836

Grew up next to Australian bush, but spent much of life overseas. Impressed by this community and a big believer in open source and citizen science / education.

Gardening links:

• Dangers of fertilizing Australian native plants: http://sesl.com.au/uploads/articles/Feeding_Native_Plants.pdf and http://www.anpsa.org.au/faq-10.html
• Best Practice Guidelines for Enhancing Urban Bird Habitat https://www.birdsinbackyards.net/sites/www.birdsinbackyards.net/files/page/attachments/doc_13_guidelines_review.pdf
• Three good videos for new gardeners (watch at 1.5x speed): https://www.youtube.com/watch?v=5v1idrq57pA https://www.youtube.com/watch?v=8UBOMh5WbTo https://www.youtube.com/watch?v=qq_2gRNnG9c
• Information dense video series on Western Australian plants: https://www.lullfitz.com.au/videos

Ecology links:

• The Natural and Cultural History of the Ku-ring-gai
  GeoRegion, New South Wales: https://linneansocietynsw.org.au/symposia/Ku-ring-gai%20GeoRegion/Conroy%20et%20al..pdf

• Download Volumes 1-10 of 'Ecology of Sydney Plant Species' at http://pratyeka.org/ecology-of-sydney-plant-species.zip
• Review of the Biodiversity of Sydney Harbour: https://publications.rzsnsw.org.au/doi/pdf/10.7882/AZ.2012.031
• Review of Sydney Harbour estuary literature: https://www.researchgate.net/profile/Paul_Gribben/publication/283903444_Sydney_Harbour_What_we_do_and_do_not_know_about_a_highly_diverse_estuary/links/568ed1f008ae78cc05160e14.pdf

Other:

• @dnicolle's guide to 'Classification of the Eucalypts': https://dn.com.au/Classification-Of-The-Eucalypts.pdf
• @kevinbonham on Australian land snail identification: https://www.inaturalist.org/people/kevinbonham

Australia:
Note that there are apparently still a lot of plants not on iNat which do occur in Australia, in which case you should check ALA. Equisetidae are an example: https://bie.ala.org.au/species/https://id.biodiversity.org.au/node/apni/2887470 vs. https://www.inaturalist.org/taxa/764793-Equisetidae

China and adjacent areas:
http://www.efloras.org/ is great for English identification keys.

Historic:
https://www.c82.net/twining/plants/?view=liknesses