1. Kochia scoparia (L.) Schrad. (summer cypress, fire bush)

K. scoparia var. culta Farw.

K. scoparia var. pubescens Fenzl

K. sieversiana (Pall.) C.A. Mey.

Bassia scoparia (L.) A.J. Scott

Pl. 358 d–f; Map 1547

Plants annual, the taproot not tuberous-thickened. Stems 30–150 cm long, erect, not succulent, not appearing jointed, much-branched, glabrous or sparsely to moderately pubescent with spreading, curled hairs. Leaves alternate, well developed, sessile or short-petiolate, not succulent. Leaf blades 0.5–8.0 cm long, those subtending flowers shorter than the others, linear to lanceolate, oblanceolate, or narrowly obovate, flattened in cross-section, not clasping the stem, narrowed to a sharply pointed tip, narrowed at the base, the margins entire but with relatively long, spreading hairs, the surfaces glabrous or sparsely to moderately pubescent with shorter, somewhat curled hairs. Inflorescences axillary toward the branch tips, sometimes appearing as terminal, interrupted spikes, the flowers paired or less commonly solitary or in small clusters, not sunken into the axis. Flowers perfect and/or functionally staminate and pistillate, the base with a tuft of hairs. Bracts absent (not counting the subtending leaf). Calyx 5-lobed to above the midpoint, persistent at fruiting, enclosing the fruit, indistinctly longitudinally angled, at fruiting each sepal developing an inconspicuous projection or prominent, spreading, papery, transverse wing, the lobes 0.3–0.6 mm long, oblong-triangular. Stamens 5 (sometimes absent). Ovary superior. Style 1, short, the stigmas 2(3), linear. Fruits 1.0–1.6 mm long, 1.5–3.0 mm in diameter (including the wings), circular or nearly so in cross-section, depressed-elliptic in outline, flattened vertically, indehiscent or irregularly dehiscent, the wall thin and papery to membranous. Seed adhering loosely to the fruit wall, positioned horizontally, 1.4–2.0 mm long, oblong-obovate in outline, flattened, the surface smooth to finely granular, brown to black, not shiny, the embryo appearing more or less ring-shaped. 2n=18. July–October.

Introduced, scattered, mostly in counties with large rivers, nearly absent from the Ozark Division (native of Europe, Asia; introduced nearly worldwide, nearly throughout the U.S.). Banks of rivers; more commonly fallow fields, railroads, roadsides, and open, disturbed areas.

Summer cypress was introduced into North America as an ornamental because its foliage turns bright red in the autumn. A number of cultivars exist, some of which have received formal taxonomic recognition. Steyermark (1963) and some other earlier botanists separated var. culta based on its threadlike leaves and var. pubescens based on its denser pubescence, but Blackwell et al. (1978), McGregor (1986a), and Judd and Ferguson (1999) all indicated that these variants grade into one another completely in naturalized populations.

According to Mühlenbach (1983), plants that he had previously (Mühlenbach, 1979) attributed to K. iranica (Hausskn. & Bornm.) Litv. are actually K. sieversiana, a taxon usually considered a synonym of K. scoparia. Blackwell et al. (1978) excluded K. iranica from the North American flora.