12. Plantago wrightiana Decne. (Wright’s plantain)

Pl. 488 e, f; Map 2231

Plants annual or short-lived perennial, with taproots and later sometimes a short, sometimes branched rootstock. Aerial stems absent or very short and inconspicuous (to 5 cm long with age), then unbranched. Leaves in a dense basal rosette (aerial stem leaves alternate but crowded), sessile or with a short, poorly differentiated petiole, strongly ascending. Leaf blades 3–12(–18) cm long, 1–7 mm wide, linear or narrowly oblanceolate (those of seedlings and overwintering rosettes sometimes narrowly obovate), angled or tapered to a bluntly or more commonly sharply pointed tip, long-tapered at the base, the margins entire, hairy, the upper surface glabrous or occasionally sparsely short-hairy, usually appearing dark green (usually darkening upon drying), the undersurface moderately to densely pubescent with shaggy or woolly hairs, appearing uniformly gray, with 1 main vein. Inflorescences 1 to several per plant, terminal, elongate spikes, 1–10 cm long 7–9 mm in diameter, densely flowered (the axis not visible between the flowers), the stalk 5–20 cm long, hairy, the axis solid. Bracts 2–3 mm long, similar in length, shorter than to about as long as the flowers, triangular-ovate, with relatively broad, translucent margins and a thick, green midnerve, angled to a bluntly or sharply pointed tip, glabrous or hairy along the midnerve. Cleistogamous flowers usually abundant. Calyces deeply 4-lobed, 2.7–3.5 mm long, slightly zygomorphic, narrowly oblong-obovate to obovate, rounded at the tip, the upper pair with somewhat broader, papery margins than the lower pair. Corollas zygomorphic, the lobes 2.4–3.2 mm long, broadly ovate with a shallowly cordate base (the lateral lobes asymmetric), rounded to very bluntly pointed at the tip, the margins entire, each with an inconspicuous brown base, otherwise white to somewhat translucent, the upper lobe slightly shorter than the others and ascending at flowering, the other lobes spreading, spreading to reflexed after flowering. Stamens 4, the anthers horned. Fruits 3.5–4.2 mm long, ellipsoid to ovoid, circumscissile below the midpoint. Seeds usually 2 per fruit, 2.5–3.2 mm long, oblong-elliptic with a shallow groove around the circumference just below the midpoint, the surface shallowly to deeply concave on 1 side, otherwise finely pitted, reddish brown, lighter in the concave portion. 2n=20. May–August.

Introduced, known thus far only from the city of St. Louis (native of Arizona, New Mexico, Oklahoma, Texas; Mexico; introduced widely in the southeastern U.S. and Missouri). Railroads.

This species was discovered in Missouri by Viktor Mühlenbach during his inventories of the St. Louis railyards. It was first reported by Steyermark (1963) in the supplement of species documented too late for inclusion in the main text of his Flora of Missouri.