Native_plants_of_australia.7z.001 -

A file ending in .001 is a "split" volume. It cannot be opened by itself because it only contains a fraction of the total data.

: Choose 7-Zip > Extract to "native_plants_of_australia" . native_plants_of_australia.7z.001

: Use a tool like Keka or The Unarchiver . A file ending in

Note: 7-Zip will automatically find and join the other numbered parts to complete the extraction. native_plants_of_australia.7z.001

: Look for files named native_plants_of_australia.7z.002 , .003 , and so on in the same location where you downloaded the first part.