I had trouble identifying them down to species until I bought a magnifier for my iPhone:

Cost me about $15 on eBay.
This allows me to take macro shots of the tiny leaves on casuarina which helps me when using an online key to identify them. Close photos of the seed pods and flowers also help with ID. Here is a photo taken of a branch which I pulled apart so the leaves can be seen and counted: I also use the lens to get a closer look at pests and irregularities on my plants.
Thought it was worth sharing.