While viewing any photo: Under the photo you will see...

You can link photos Alphabetically or by Category
In the Alphabetical Index (for instance)
Click on letter for the species and click to the right of the Drop Down Box. Scroll down the section to the species, click on it then click on the Proceed button. Then click on the Add Button and it will be associated.
Joe geotags the photo which associates it with the trail on which it was shot. If you go to the trail and look in the middle right side of the description for the Flora & Fauna Sections, you will see that the photo has been associated with this trail. When you click on the Species description, you will see our attempts at describing it. When you click on the little camera you will see the "Detail photo", a photo that an administer felt best represents the species, when you click on the map association, you will see all hikes on which this species has been identified.
If you don't know the identification but would like to have the photo identified, post it to the Unidentified Species and hopefully someone will know what it is.
HikeArizona is becoming better, but more complicated at the same time. Flora & Fauna can be found alphabetically. If you click on the letter and scroll down to the bottom of the first page under that letter you will find the species. At the top left of each Section is a Drop Down Box that lets you filter the Section for your interests.