3. Silene conoidea L. (large sand catchfly)

Map 1482, Pl. 348 d

Plants annual. Stems 12–30 cm long, erect, unbranched or branched, moderately to densely pubescent with stalked glands. Basal leaves usually absent at flowering, when present usually shorter than the largest stem leaves, short- to long-petiolate. Stem leaves opposite, mostly 6–12 pairs, sessile. Leaf blades 2–5(–8) cm long, not succulent, oblanceolate or narrowly lanceolate, tapered at the base, angled to a bluntly or sharply pointed tip. Flowers perfect, in open terminal clusters or panicles, the stalks (1–)2–3 cm long, densely pubescent with stalked glands, the bracts paired and resembling small leaves, with green margins. Sepals (15–)20–25 mm long, the tube with 25–30 parallel nonanastomosing nerves, conical at flowering, becoming flask-shaped and inflated toward the base at fruiting, the nerves green, pale or somewhat translucent between the nerves, densely pubescent with stalked glands, the lobes narrowly lanceolate, green, tapered to a sharply pointed tip, the margins thin and white. Petals 5, 28–40 mm long, the expanded portion 8–12 mm long, entire, irregularly scalloped, or notched at the tip, pink, with a pair of small appendages on the upper surface at the base of the expanded portion. Styles 3. Fruits 11–16 mm long, dehiscing apically by 6 teeth, with a basal stalklike portion 0.5–2.0 mm long. Seeds 1.2–1.7 mm wide, kidney-shaped, the surface tuberculate, brown. 2n=20, 24. May–July.

Introduced, uncommon, known thus far only from the city of St. Louis (native of Europe, Asia; introduced in the northwestern U.S. sporadically east to Texas and Missouri; Canada). Railroads.

This showy species was first collected from Missouri in 1957 by Viktor Mühlenbach during his botanical inventories of the St. Louis railyards. Although he collected it several times, it has not been encountered elsewhere in the state.