Bolbitiaceae --  Agrocybe, Bolbitius & Conocybe

    Agrocybe praecox    (California, parks, rarely in nature)

Collection: California
Agrocybe putaminum

I had seen this Agrocybe before and wondered where to put it, but Else Velinga alerted me recently that this is the same  species that have been conquering Europe at speed on mulch beds.

Spores:     Cheilocystidia:  

    Bolbitius aleuriatus    [in depth-->]

    Bolbitius vitellinus

Conocybe apala (~Conocybe lactea)  Together with Panaeolus foenisecii, these two are the most common little mushrooms occupying the freshly cut grass lawns
Typical cheilocystidia     [more]

    Conocybe tenera