Black hawthorn (Crataegus douglasii) is a native vigorous deciduous shrub which grows up to 8 m tall.  The trunk is sturdy and has woody branches with stout thorns.   Many green oval(ish) toothed leaves appear in spring.   Clusters of white (showy) flowers at the ends of thin branches.    The individual flowers have 5 rounded petals.

After flowering, dark red berry-like fruits appear,  which develop into blackish pomes.    The pomes are edible, but have large seeds/pits.   Wildlife feeds on the leaves and the pomes.   The pomes drop in the fall and we can find them on the ground.    The leaves shed in late fall and the bark turns a greyish color.

We encounter black hawthorn at mid-elevation open spots (including the upper grasslands), often in gullies or drainage slopes.   We time our hikes to see the flowering phase, in mid-late May, but we encounter black hawthorn throughout the hiking season.

A gallery of photos of black hawthorn is provided here as a Google Photos album – Hawthorn (link)

The album is also shared here as an embedded slideshow: