3. Chenopodium berlandieri Moq. (pitseed goosefoot)

C. album L. var. berlandieri (Moq.) Mack. & Bush

Pl. 354 g, h; Map 1523

Plants annual, sometimes with an unpleasant odor. Stems 20–120(–200) cm long, erect or ascending, usually few- to several-branched above the base and below the inflorescence, glabrous or more commonly sparsely to moderately white-mealy, sometimes reddish-tinged or reddish-striped. Leaves mostly long-petiolate. Leaf blades 1–12(–15) cm long, mostly 1–3 times as long as wide (1–5 cm wide), mostly rhombic to ovate-rhombic, less commonly ovate-triangular, the uppermost usually linear to narrowly lanceolate, angled or tapered from below the midpoint to a usually sharply pointed tip, the middle lobe not appearing unusually elongate, angled at the base, green or reddish-tinged, thin and herbaceous to thickened, somewhat leathery, and slightly succulent in texture, the margins entire to irregularly several-toothed (the basal pair of teeth usually larger than the others), the upper surface glabrous or sparsely to moderately mealy at maturity, not shiny, the undersurface usually densely white-mealy. Venation noticeably branched, with 1 or 3 main veins. Inflorescences axillary and terminal, consisting of short spikes with small clusters of flowers, the terminal ones usually grouped into small to relatively large panicles. Flowers not all maturing at the same time. Calyx 5-lobed nearly to the base, covering the entire fruit except sometimes for a minute area surrounding the style, the lobes 1.0–1.5 mm long, ovate to triangular-ovate, rounded or bluntly pointed at the tip, with a relatively pronounced broad keel or raised area along the midvein dorsally, densely white-mealy. Stamens 5. Stigmas 2. Fruits 1.0–1.5 mm wide, depressed-ovoid, the seeds positioned horizontally, the wall thin, membranous, and somewhat translucent, appearing honeycombed (often visible only with magnification), finely pitted, the pits usually more or less rectangular, separated by a network of thin ridges, the wall usually difficult to separate from the seed (except around the style, where the fruit wall then often appears yellowish and distinctly lighter than the surrounding tissue). Seeds reddish brown to black, shiny, finely wrinkled, rounded to very bluntly angled along the rim. 2n=36. July–October.

Scattered nearly throughout the state (U.S., Canada, Mexico; introduced in Europe). Banks of streams, rivers, and spring branches, less commonly openings of mesic to dry upland forests and upland prairies; also crop fields, roadsides, railroads, and open, disturbed areas.

Chenopodium berlandieri and C. bushianum can be difficult to separate morphologically, which has led some botanists to treat them as varieties of a single species. Variation within the widespread C. berlandieri also has led to the recognition by some earlier monographers of numerous intergrading subspecies, varieties, and forms (Wahl, 1952–1953). Only two of the varieties are accepted as distinct in Missouri, and there is considerable morphological overlap in some populations even for these. The var. berlandieri refers to plants primarily of the western United States similar to var. boscianum, but with leaf blades having a somewhat elongate central lobe.