I came across this information while browsing reddit the other day and it may come in handy for anyone looking to gather high level crafting items. Below are links for the lazy.
Botany Nodes
Mining Nodes
Spreadsheet of both
These nodes appear to have a cooldown so they won't pop up again until the time listed. You sort of have to mine away the debris as it were out of the way so you can get the item so pay attention to the slot allocation if you want to get a particular item from the spot.