It’s Mediterranean Barley, a/k/a Knee Barley, Geniculate Barley. Scientific name hordeum marinum ssp. gussoneanum. 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.
This particular strain of wild barley has important genetic properties that are used in hybridization with wheat. Barley-wheat hybrids have improved salt stress tolerance, better root aeration and water-logging tolerance. See Efremova et al., Substitution of Hordeum marinum ssp.gussoneanum chromosome 7HL into wheat homoeologous group-7, Euphytica, July 2013 Vo. 192 No. 2 pp. 251-157.
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.”