7. Atriplex truncata (Torr.) A. Gray (silver scale, wedge-leaved orache)

Pl. 352 f; Map 1517

Stems 15–60 cm tall, erect or strongly ascending, the branches ascending. Leaves all alternate, sessile to short-petiolate. Leaf blades 0.5–3.0 cm long, less than 3 times as long as wide and widest toward the base, ovate-triangular to ovate, short-tapered or angled at the base, the uppermost leaves sometimes shallowly cordate and clasping the stems, bluntly to sharply pointed at the tip, sometimes with a pair of short, blunt, spreading basal lobes, the margins otherwise entire or with a few shallow, irregular teeth, appearing silvery gray on both surfaces (the mealiness sometimes difficult to discern on older specimens). Staminate flowers appearing axillary among the uppermost leaves. Pistillate flowers in axillary clusters, all similar, lacking a perianth. Bracts at fruiting fused to far above the midpoint, 2–3 mm long, obtriangular to wedge-shaped in outline, appearing sessile or narrowed to a short, stalklike base, the more or less truncate free apical portion of the margins with usually 3 teeth (sometimes also slightly irregular between the teeth), the fused portion becoming hardened and somewhat bony, the surfaces usually lacking tubercles or crests. Fruits difficult to separate from the bracts. Seeds all similar in size and color, 1–2 mm long, brown, more or less shiny, the tip of the radicle (seedling root) positioned above the remaining body of the seed. 2n=18. July–September.

Introduced, uncommon, known thus far only from the city of St. Louis (western U.S. east to Montana and New Mexico; Canada). Railroads.

This species was first reported for Missouri by Frankton and Bassett (1970) based on collections from the St. Louis railroad yards by Viktor Mühlenbach, who also discussed the occurrences (Mühlenbach, 1979).