The cup-shaped, solitary, salverform flower tapers off into a narrow tube. Their colors vary enormously, although lilac, mauve, yellow, and white are predominant. The grass-like, ensiform leaf shows generally a white central stripe along the leaf axis. The leaf margin is entire. Crocuses typically have three stamens. The spice saffron is obtained from the stigmas of Crocus sativus, an autumn-blooming species.