I'm seeking any & all sources of information on plant communities for Central Texas that enhance the growth of beneficial soil fungi, especially mycorrhizal fungi. Thanks.

Various beneficial fungi naturally exist in all good, well balanced, aerobic homemade mature compost piles!

The more woody or high cellulose carbon materials that were used in the aerobic composting process, the more beneficial fungal the mature compost will be anyway.

Another way to get more various aerobic beneficial fungi species in your compost pile or topsoil, is to add more aerobic beneficial fungi to aerated compost tea recipes, then apply it as a soil drench application.

Good fungal foods for aerated compost tea recipes are any forms of soy, or milk, yogurts, or cheese products, or rich forest dirt, 100% fish oil or 100% whole fish meal products, or fresh seaweed products.

All of these potential suggestions or ideas are found from Dr. Elaine Ingham's book: "The Compost Tea Manual".

Hope that helps.
Happy Gardening!