It is a Lamb's quarters.

Scientific name: Chenopodium album.

A fast-growing annual herb with an upright, branching green stem that can mature from about 30 cm to over 1.5 m tall. Leaves are arranged alternately on slender petioles and are variable in shape: lower leaves are often broadly triangular to diamond-shaped or ovate with irregular, shallowly toothed or wavy margins, while upper leaves become narrower and less toothed. The leaf surface is dull green to gray-green, often with a whitish, powdery or mealy coating, especially on young leaves and growing tips. Venation is pinnate with a prominent central midrib and smaller side veins curving toward the margins. Flowers are small, greenish, petal-less, and clustered densely in branched spikes or panicles at the stem tips and leaf axils. The plant produces many tiny black seeds enclosed in dry, papery floral parts..

Lamb's quarters is often treated as a weed, but its young leaves are edible and have been used like spinach; it is also closely related to quinoa..

The plant shows gray-green, somewhat mealy-looking foliage with alternately arranged petiolate leaves. The leaves are triangular to ovate, with irregular wavy-toothed margins and a prominent central vein, which are characteristic of lamb's quarters and other goosefoot relatives. The pale, powdery appearance on the young leaves near the growing point is a strong clue for Chenopodium album. The lack of flowers or fruit in the image prevents a fully certain identification, and similar species such as orache, Atriplex species, or related Chenopodium species can look very similar at this stage.