This introduced plant is a summer annual about 2-5' tall (in more tropical climates, it is a perennial). More or less erect, Mexican Tea branches occasionally to frequently; Small side branches frequently develop from the axils of the leaves. The stems are terete to slightly angular, hairless, conspicuously veined, and variably colored often some combination of olive green, dull red, and cream. The alternate leaves are up to 4" long and 1½" across; they are ovate to narrowly ovate, medium green to yellow-green or red-green, and hairless. The bases of these leaves are always wedge-shaped and never rounded. The leaf undersides are never white-mealy. The leaf margins are highly variable, even on the same plant smooth, undulate, bluntly dentate, or somewhat pinnatifid. The upper leaves are smaller in size than the moderate to lower leaves, and their leaf margins are more smooth. Both the stems and leaves have minute glands that secrete an aromatic oil; they exude a somewhat musky medicinal scent. The upper stems and smaller side stems terminate in spikes of sessile flowers (up to 1' long) that are interspersed with small leafy bracts. The small greenish flowers are arranged in dense clusters along these spikes. Each flower is a little less than ¼" across, consisting of 5 green sepals, a rather flat pistil with tiny styles, and 5 stamens with large white anthers. The small sepals are ovate in shape and curved inward; they are neither hairy nor white-mealy. The anthers are the most conspicuous part of the flower. The blooming period occurs from mid-summer into the fall and lasts 2-3 months. The bisexual flowers are wind-pollinated, although they can also self-pollinate themselves. Each flower is replaced by a single tiny seed (achene); a thin membrane surrounding the seed is rather loose and easily removed. The seeds are round, flattened, black, and shiny; they are small enough to be blown about by the wind. The root system consists of a taproot.