Pluteus lutescens
The yellow stem of this mushroom is a distinctive
Pluteus lutescens grows on wood and
produces a pink spore print.  
Pluteus romellii is a synonym.
Pluteus lutescens
Pluteus lutescens
pileipellis cells of Pluteus lutescens
The brown cells in this micrograph appear on the cap surface
(pileipellis) of
Pluteus lutescens.  Spherical and sometimes pendulum
shaped, they are described technically as sphaeropedunculate.
Note small, round spores (5-6 microns wide).
See Pluteus lutescens at
See Pluteus romellii at
Fungi of Iowa