You should be using an aperture of f8-f16 to get enough DOF ( depth of field ) so more of the fungi are in focus. Look for tutorials on the web and Ephotozine about DOF, macro photography and the techniques associated with it.
You need a tripod and a cable release to ensure sharp results and use Live View on your camera or Mirror Lock-up when taking macro photos. This is to avoid any vibrations caused by the mirror slapping up when releasing the shutter. Any vibrations when shooting at high magnifications will also be magnified and cause the image to be blurred. I use a tripod, shutter release cable and Live View when taking macro shots. My portfolio shows whether this has been effective or not.
If you don't have a flash then take some white, silver and gold card with you to reflect light into dark shadow areas. This helps to show the form of the fungi and helps shadow detail. Again, my portfolio shows how this helps avoid blocked shadows.
Always think about composition and get down to the level of what you are shooting.
You could have cleaned the fungi up a bit by removing the soil from the caps. This helps the aesthetics of the shot a great deal.
Use manual, aperture priority or shutter priority when taking photos as this will help you learn more about photography than just using Auto. There are tutorials that will teach you the differences and when to use the different modes of aperture/shutter control. Your camera's manual should give a reasonable explanation as to the differences as well.
Use the Histogram to check the tonal information of each shot. If the bulk of the graph is to the left it's too dark and needs to be lightened by reducing the shutter speed to let more light in ( or opening the aperture will have the same effect ). If it's to the right, it's too light ( over exposed ) and the opposite should be done.
Hope this helps, Alan.