Biennial, and does not produce a flowering stalk until the second year (existing in the first year as a lettuce-like clump, each leaf with a thick white vein down the middle). Extremely tall once the flowering stalks are produced. This main stem often branches off into several, each of which terminates in a bristle-like flower structure. This structure is roughly the size and approximate shape of an egg, and is composed of many sharp green structures, with many small lavender flowers interlaced between them. Usually only some of these flowers bloom at one time, creating one or more 'rings' or 'belts' of dense flowers around the top or midsection of the flowering structure. The stems may take a long time to fall over and degrade, leaving the skeleton of the flowering structure behind, which has an interesting geometric pattern of holes and spikes.