One form of thorny shrub with yellow flowers is the Golden Showers rose, according to SFGate. It is a climbing rose that does well in full sun and attracts butterflies.
Rose Gardening Made Easy notes that the Golden Showers rose blooms throughout the summer and fall. Wayside Gardens mentions that the flowers bloom strongly in spring, but the rose blooms less frequently into autumn. The leaves are a deep green and grow on thorny canes. The Golden Showers rose can grow to 12 feet or taller. Its yellow flowers give off the scent of licorice and tea. The flowers are large, and the plant itself is disease-resistant.