FL, Keys, 20071229
Buttonwood, mostly mushrooms.

Across the fence. Rained cats and dogs four days ago.

Agaricus []

GEN small mushroom, solit, in leaf litter near bay
ST 30x3mm, narrower bel, creamy white, smooth, hollow, staining faintly rufescent
CAP 30mm wide, plane, white context, dk brown fibrils becoming solid in center, narrow sterile marg, no bruise, K?
FLESH whitish, no bruise
VEIL partial, skirt-like white ring near top of stalk
GILL brown, free, close
SPORE print v dk brown

Marasmius []

GEN small mushroom, several scattered, in leaf litter near bay near base of strongbark
ST 15-20x1.5mm, curvy, rubbery tough but bending, terete to strongly compressed, solid, cap-colored to whitish, much white cotton at base
CAP 5-10mm wide, dome, tawny golden, solid, smooth, dull, sl umbo, marg sl curled under, not striate
VEIL none
GILL whitish to sl yellish, att, sl decur, close, shallow
SPORE failed
Try M. insipidus, C. strictipes, C. fusipes.

Cystolepiota petasiformis []

GEN small mushroom, small clusters scattered, in humus near pigeon plums
ST 15-20x1-1.5mm, white, powdery like cap, bending v easily but not breaking, much powdery white mycelia about base binding litter
CAP to15mm wide, dome to broad cone, whitsish to brownish, v d powdery like it has a disease, powder brushes off and makes clouds whenever touch it, tip often acute and elongated
VEIL partial, leaves powdery v fragile clump near top of stalk, still visible on about half my specimens
GILL white, free, close, aging a bit yellowish
SPORE failed
Joshua Birkebak tentatively IDed this one for me.

Marasmius haematocephalus []

Leucoagaricus serenus-group []

Leucoagaricus roseiceps []

Leucoagaricus rubriceps []

Leucoagaricus rubrotinctus []

GEN small mushroom, in hardwood leaf litter, solit
ST 35-45x2-4mm, shiny-silky, whitish to yellowish brownish, even to enlarged below, smooth, fragile, flesh whitish to sl yellowish and v soft
CAP 15-20mm wide, plane, not striate, pinkish to grayish or rich reddish brown in center, fibrillose breaking in radial streaks exposing white context, smooth to min roughened
VEIL partial, leaves fragile collar-like ring near top of stem
GILL free, broad, close, pale yellowish
SPORE print white
Joshua Birkebak is IDing this one for me.

Lepiota theirsii-like []

GEN small mushroom, in hardwood leaf litter, solit
ST 25-30x2.5-4mm, enlarged below, shiny whitish to pale pinkish esp bel, smooth, fibrous, stiff and breaking
CAP 15mm, bell to nearly plane, white w scattered pinkish-brown min scales becoming solid in center, low umbo
VEIL partial, leaves collar-like ring near top of stem, pinkish-brown on underside
SPORE print white
Joshua Birkebak says it looks identical to L. theirsii, a California species that grows under cypress, but it seem unlikely this is the same species!

Bolbitius keys-scurfy-plum []

Same place; see 20071210.

Laccaria []

GEN small mushroom, in hardwood leaf litter, solid
ST 40x1mm, perfectly straight, stiff, whitish puber over pale pinkish-lilac, whitish down at base
CAP 20-25mm, wide, nearly plane, pale pinkish-lilac, whitish puber, radially ridged/furrowed, sl sunken center
VEIL none
GILL distant, thick, pale pinkish-lilac, shallow, att, white right where attaches to stem
SPORE failed

Phellinus rimosus-like []

GEN avg shelf mushroom, at base of red ironwood (Reynosia septentrionalis)
ST none
CAP 100mm wide, hoof, rich cin brown velvet at growing margin, black concentric ridges and corky inside, K?
FLESH rich cin brown, dry, corky, v tough, perennial
PORE cin brown, 6-7 per mm