Xi Hong Hua

Crocus sativus L. (Iridaceae) is a small autumn-flowering perennial geophyte, sterile and known only in cultivation, propagated by replanting its underground corms. Each corm is globose, 2 to 4 cm across, covered with a fibrous brown tunic, and produces a tuft of narrow, grass-like, dark green leaves 20 to 40 cm long, each with a prominent pale central stripe. The flowers appear in autumn, arising directly from the corm on short white tubes; each flower is funnel-shaped, 3 to 5 cm long, with six lilac to violet-purple tepals and a single conspicuous style branching above the perianth into three long, thread-like, deep red to orange-red stigmas about 2.5 to 3.5 cm long. These bright red stigmas, hand-picked at dawn and gently dried, constitute saffron, the most expensive spice by weight. In Chinese medicine, where the spice was introduced from Persia and India via Tibet, the dried stigmas are known as Xi Hong Hua or Zang Hong Hua.