Galinsoga quadriradiata, commonly known as shaggy soldier, hairy galinsoga, or Peruvian daisy, is an annual herb in the family Asteraceae. Native to the mountainous regions of Central and South America, particularly Mexico and the Andes, it has become a widespread, opportunistic weed throughout much of the temperate world. The genus name Galinsoga honors Ignacio Mariano Martínez de Galinsoga, an 18th-century Spanish court physician and director of the Madrid Botanical Garden, while the species epithet quadriradiata refers to the four (sometimes five) ray florets that characterize its small flower heads. Historically, it is often grouped with Galinsoga parviflora (gallant soldier) as a persistent "garden pest," but in its native Andean range, it has a long-standing history as a valued, resilient green leafy vegetable.

The plant is a small, fast-growing herbaceous annual that typically reaches heights of 20 to 60 centimeters. It features opposite, ovate-to-triangular leaves with serrated margins, covered in distinct, shaggy, multicellular hairs—a feature that distinguishes it from its smoother-leaved relative, G. parviflora. Its most identifying features are the tiny, composite flower heads: each head is only a few millimeters wide, possessing a yellow disc of fertile florets surrounded by a few small, white, three-lobed ray florets that often appear withered or "shaggy." It thrives in disturbed soils, cultivated garden beds, and moist, nutrient-rich anthropogenic habitats, where it can complete multiple generations in a single growing season.

Galinsoga quadriradiata is a staple wild green in parts of the Andes, notably in Colombia and Ecuador, where it is known as guasca. It is the essential, defining ingredient in ajiaco santafereño, a traditional hearty potato soup from the Bogotá region. When used in cooking, the plant provides a mild, earthy, and slightly grassy flavor that is often compared to a blend of spinach and artichoke. The leaves and tender stems are typically harvested before the plant sets significant amounts of seed, then chopped and added to soups or stews in the final stages of cooking to preserve their volatile aromatic compounds, which are essential to the authentic flavor of the dish.

Nutritionally, Galinsoga quadriradiata is a highly underrated source of vitamins and minerals. It contains significant levels of Vitamin A, Vitamin C, calcium, and iron, making it a nutritionally dense "weed" that can supplement the diets of foraging communities. Its biochemical profile includes a variety of flavonoid glycosides and phenolic acids that function as antioxidants, helping the plant protect itself from environmental stressors in the high-altitude Andes. While it is rarely studied in modern pharmacological literature compared to major crops, traditional use confirms its role as a nutrient-rich potherb that contributes to metabolic health through its supply of essential micronutrients and dietary fiber.

Major ingredients derived from this food source include fresh *guasca* leaves, dried herb bundles for spice blends, and artisanal potherb additions for traditional soups. Significant bioactive compounds associated with the source include **chlorogenic acid**, **caffeic acid derivatives**, and various **luteolin-based flavonoids** that contribute to its antioxidant capacity.