Turmeric, scientifically known as Curcuma longa, is a rhizome (underground stem) of a flowering plant in the ginger family, characterized by its knobby, segmented structure and bright yellow to orange-yellow color, used as a spice and in traditional medicine. 
Here's a more detailed description:
Appearance and Structure:
Rhizome:
Turmeric is the rhizome, an underground stem that grows horizontally, not a true bulb. 
Knobby and Segmented:
The rhizome has a knobby, segmented appearance, resembling fingers or tubers. 
Color:
The rhizome is known for its bright yellow to orange-yellow color, which is due to the presence of curcuminoids. 
Peel:
The rhizomes have a thin, slightly brown peel (peridermis layer) covering an orange-yellow flesh. 
Aroma and Taste:
Turmeric has a warm, bitter, black pepper-like flavor and an earthy, mustard-like aroma. 
Plant Characteristics:
Family: Turmeric belongs to the ginger family (Zingiberaceae). 
Native to: The plant is native to the Indian subcontinent and Southeast Asia. 
Growth: It's a perennial, rhizomatous, herbaceous plant that requires warm temperatures and high rainfall to thrive. 
Leaves: It has large, oblong leaves that are dark green on the upper surface and pale green underneath. 
Flowers: It has yellow-white flowers that grow on a spike-like stalk and have small, brown seeds