The common cooking ginger is an herbaceous perennial with upright stems and narrow medium green leaves arranged in two ranks on each stem. The plant gets about 4 ft (1.2 m) tall with leaves about 3/4 in (1.9 cm) wide and 7 (17.8 cm) long. Ginger grows from an aromatic tuberlike rhizome (underground stem) which is warty and branched. The inflorescence grows on a separate stem from the foliage stem, and forms a dense spike, to 3 in (7.6 cm) tall. The bracts are green with translucent margins and the small flowers are yellow green with purple lips and cream colored blotches. Most gingers in cultivation are sterile cultivars grown for the edible rhizome, and the flower is rarely seen. There is a cultivar of Zingiber officinale known as 'Sunti', which comes from Java and is similar to the common cooking ginger, but forms smaller rhizomes. It is used in the same way as common ginger but is said to have better medicinal qualities.
Zingiber officinale Plant Profile - Floridata, http://www.floridata.com/Plants/Zingiberaceae/Zingiber%20officinale/861 (accessed January 26, 2017).