5. Silene dichotoma Ehrh. ssp. dichotoma (forked catchfly)

Pl. 347 a, b; Map 1484

Plants annual. Stems 20–50(–100) cm long, erect, branched, roughened with relatively long, downward-angled hairs. Basal leaves usually withered at flowering, when present usually shorter than the largest stem leaves, with a poorly developed, short petiole. Stem leaves opposite, mostly 5–10 pairs, with a poorly differentiated, short petiole or sessile. Leaf blades 2.0–8.5 cm long, oblanceolate to narrowly lanceolate or narrowly ovate, tapered at the base, angled or tapered to a sharply pointed tip, sparsely to moderately pubescent with more or less spreading hairs. Flowers perfect, in open, terminal, more or less 1-sided panicles, these often forked 1 or more times toward the base, occasionally appearing as leafy branches with solitary axillary flowers, the stalks absent or to 0.3(–1.5) cm long, roughened-hairy and sometimes also with stalked glands, the bracts paired and resembling small or nearly full-sized leaves, at least the uppermost with thin, white margins. Sepals 8–12(–15) mm long, the tube with 10 parallel nonanast­omosing nerves, ellipsoid, not inflated, the nerves green or purplish-tinged, pale between the nerves, sparsely to moderately pubescent with relatively long, spreading hairs, the lobes narrowly triangular, green, tapered to a sharply pointed tip, the margins thin and white. Petals 5, 13–20 mm long, the expanded portion 4–7 mm long, 2-lobed at the tip, white or rarely pink, with a pair of small appendages on the upper surface at the base of the expanded portion. Styles 3. Fruits 7–10 mm long, dehiscing apically by 6 teeth, with a stalklike base 1–3 mm long. Seeds 0.8–1.0 mm wide, kidney-shaped, the surface tuberculate, grayish brown. 2n=24. June–September.

Introduced, uncommon, known thus far only from Cape Girardeau County and the city of St. Louis (native of Europe, Asia; introduced in the northern U.S. south to Georgia, Missouri, and California, also Texas; Canada). Old fields and railroads.

Nonweedy plants from southern Europe with well-developed rosettes of basal leaves that are densely hairy and relatively dense inflorescences have been called ssp. racemosa (Otth) Graebn. Some European botanists recognize one or more additional infraspecific taxa, but none of these is weedy or has become introduced in North America.