It is because of the addition of raw flour.

The taro, also known as ground chestnut, vegetable soil round, fragrant ginseng, ground chestnut, soil Luan Er. Leguminosae, twining herbaceous plants, earth terrible child genus perennial trailing herb, generally for annual cultivation. Tubers are globular, shaped like small potatoes, 2 ~ 7.5 cm in diameter, yellow-brown skin, white flesh, is the edible part of the people cultivated sought.

The appearance of taro also looks very different from taro, it is a herbaceous vine with a huge tuber, heart-shaped leaves lower alternate, upper opposite, exposing the most important feature of its home is the leaf axil bead buds, irregular cross-section of the tuber is a bright purple color, while the varieties grown in China is white.

Extension

Taro for the country, often taro and taro confused, and for the Japanese across the sea, is often taro and spinach family of purple potatoes confused, the reason is very simple, because the purple potatoes are also purple, the texture and taro is almost the same, so a lot of stores in the production of taro snacks will be added to purple potatoes to fill the number, and over time it is often confused.

Refer to Baidu Encyclopedia - Taro