Book excerpt: Allium crops include more than 30 species, many of which (for e.g. onions, shallots, garlic, leeks, bunching onions, and chives) are of economic importance. Bulb onions rank second only to tomatoes in terms of global production. Alliums are farmed and harvested in a range of climatic conditions worldwide, forming important parts of local diets. This book provides a comprehensive review of major and minor Allium crops from scientific and horticultural perspectives. It broadly covers modern biology (including genetics and breeding), propagation, production, processing, and nutritional and health benefits. This is an essential resource for scholars, researchers and students in plant science and agriculture, in addition to molecular biologists, plant breeders, agronomists, consultants, and extension specialists.