Flower:

Numerous small, tightly packed, spike-like clusters at the top of the stem and arising from the upper leaf axils. Flowers lack petals, have 1 to 3 yellow stamens and an oval, green ovary with a 2-parted style at the tip.

Cupping the flower is a green calyx with 5 lobes .7 to 1.1 mm long. Bracts are leaf-like but may be absent especially on the upper part of the stem. The calyx and stalks are densely covered in sticky, glandular hairs.

Leaves and stems:

Leaves are alternate, ½ to 1½ inches long, ¼ to 1 inch wide, egg-shaped to oblong in outline, with 1 to a few rounded to angular lobes on each side, the lobes sometimes further lobed or shallowly toothed, the leaf tip usually rounded, the base wedge-shaped, on a stalk up to 1 inch long. Stems are unbranched or branched from the base, erect to ascending, and ridged. Leaves, stalks and stems are all covered in sticky, glandular hairs.

Fruit:

Fruit is a dry seed enclosed in the persistent ovary shell (pericarp) that matures from green to blackish and loosely wraps the seed. The persistent calyx mostly covers the fruit at maturity. Seeds are flattened oval to round, up to .8 mm long.

Notes:

Jerusalem Oak is an uncommon annual found mostly in disturbed soils such as gravel pits, roadsides, railroads, empty lots, and the occasional garden. It is distinguished from related Chenopodium species by the pinnately lobed leaves and abundant sticky, glandular hairs. Only recorded 9 times in Minnesota and only 3 times since 2005, it is likely under-reported in the state. Ours was a chance encounter while exploring a gravel pit in eastern Lake County.