Large, gilled mushrooms growing in a mostly shaded Sequoia Sempervirens and mixed forest. The largest measured approx. 11 inches across.

An iNaturalist Introduction to Mushrooming, 6-minute Utube video by Christian Schwartz (leptonia on INat) https://www.youtube.com/watch?v=LKF_pIY0Zpc

The Prince (Agaricus augustus)
Mycoweb: https://www.mykoweb.com/CAF/species/Agaricus_augustus.html
"Cap 6-32 cm (up to 12.6 inches) broad, convex expanding to plane; surface dry with yellow-brown to brown scales, bruising yellow in age, staining yellow slowly with KOH; Flesh thick, odor sweet, anise or almond-like.
Lamellae: Gills close, free, pale at first, then blackish-brown at maturity.
Stipe: 10-37 cm long, up to 6 cm thick, equal to enlarged at base, frequently buried; smooth above ring, scaly below; veil with cottony patches, later becoming membranous, forming a skirt-like annulus.
Spores: 7.5-10.5 x 5-6.5 µm, elliptical and smooth. Spore print chocolate-brown.
Habitat: Fruiting during the warm months of the year, especially late summer. Most common along the coast after periods of foggy weather. Often found under conifers like redwood, Monterey pine, Monterey cypress, but may also occur in parks and gardens.
Edibility: An excellent edible, one of the very best. Unfortunately it is frequently infested with fly larvae.
Comments: One of the largest and most spectacular Agaricus species in California. The yellow-brown scaly cap, sweet odor, blackish, free gills make it a distinctive species."
https://www.mykoweb.com/CAF/species/Agaricus_augustus.html

Mushrooms of the Redwood Coast: Comprehensive Guide to the Fungi of Coastal Northern California, Siegel and Schwarz, 2016.

California Mushrooms: The Comprehensive Identification Guide, D. Desjardin, M. Wood, and F. Stevens, 2nd printing 2019.

Fungi of California: Home page https://www.mykoweb.com/index.html and https://www.mykoweb.com/CAF/ and https://mykoweb.com/CAF/skey.html and https://www.mykoweb.com/CAF/keys/index.html