This shrub is growing in Fish Creek Park, at Votier's Flats. Also saw another one at Inglewood Bird Sanctuary. It looks very similar to Canada Buffaloberry. Tiny (about 4 mm across), brownish yellow flowers, no petals, only 4 sepals. This photgraph shows a male specimen, as it has 8 stamens per flower.

"Shepherdia argentea (Silver Buffaloberry or Bull berry, thorny buffaloberry) is a species of Shepherdia, native to central North America from southern Canada (Alberta, Saskatchewan, Manitoba) south in the United States to northern California and New Mexico.

It is a deciduous shrub growing to 2-6 m tall. The leaves are arranged in opposite pairs (rarely alternately arranged), 2-6 cm long, oval with a rounded apex, green with a covering of fine silvery, silky hairs, more densely silvery below than above. The flowers are pale yellow, with four sepals and no petals. The fruit is a bright red fleshy drupe 5 mm in diameter; it is edible but with a rather bitter taste.[2]

The berry is one of the mainstays of the diet of the Sharp-tailed Grouse, the provincial bird of Saskatchewan.

The plant contains a low concentration of tetrahydroharmol, which acts as a psychedelic drug in high enough doses." From Wikipedia.