It’s Foxtail Barley, Hordeum murinum. It belongs to the family of grasses, along with wheat, rice, maize, millet, sorghum, sugar cane and others. Barley is an edible grain and a source of sugar. Enzymes from barley sprouts are used in beer making.
It’s an annual herb that usually blooms March-April-May. It grows wild all over California including the park. When it’s done blooming it displays a genius for spreading its seeds by injecting them into your socks, pants, and into the fur and sometimes orifices of dogs, occasionally with painful and expensive consequences.
Barley: Production, Improvement, and Uses, by Steven E. Ullrich (Wiley, 2010). A 500-page reference.
About the book (left): “Barley is one of the world’s most important crops with uses ranging from food and feed production, malting and brewing to its use as a model organism in molecular research. The demand and uses of barley continue to grow and there is a need for an up-to-date comprehensive reference that looks at all aspects of the barley crop from taxonomy and morphology through to end use. Barley will fill this increasing void. Barley will stand as a must have reference for anyone researching, growing, or utilizing this important crop.”