Safflower is a fast growing, erect, winter/spring-growing annual herb, that resembles a thistle. Originating from a leaf rosette emerges a branched central stem (also referred to as terminal stem), when day length and temperature increase. The main shoot reaches heights of 30–150 cm. The plant also develops a strong taproot, growing as deep as 2 m. First lateral branches develop, once the main stem is about 20–40 cm high. These lateral branches can then branch again to produce secondary and tertiary branches. The chosen variety as well as growing conditions influence the extent of branching.

The elongated and serrated leaves reach lengths of 10–15 cm and widths of 2.5–5 cm and run down the stem. The upper leaves that form the bracts are usually short, stiff and ovate, terminating in a spine. Buds are borne on the ends of branches, and each composite flower head (capitulum) contains 20–180 individual florets. Depending on variety, crop management and growing conditions, each plant can develop 3–50 or more flower heads of 1.25–4 cm diameter. Flowering commences with terminal flower heads (central stem), followed sequentially by primary, secondary and sometimes tertiary branch flower heads. Individual florets usually flower for 3–4 days. Commercial varieties are largely self-pollinated. Flowers are commonly yellow, orange and red, but white and cream coloured forms exist. The dicarpelled, epigynous ovary forms the ovule. The safflower plant then produces achenes. Each flower head commonly contains 15–50 seeds; however, the number can exceed 100. The shell content of the seeds varies between 30 and 60%, the oil content of the seeds varies between 20 and 40%.