Linaria repens

Perennials, reproducing vegetatively by rhizomes. Fertile stems erect, 12–68 cm; sterile stems to 15 cm. Leaves of fertile stems: blade narrowly elliptic, oblanceolate, or linear, flat, sometimes revolute distally, 4–50 × (0.5–)0.7–6 mm, apex acute. Racemes 1–43-flowered, dense in flower, lax in fruit; bracts linear, 2–11(–12) × 0.3–1.5 mm. Pedicels erect, 2–5 mm in flower, 2.5–12(–14) mm in fruit. Calyx lobes linear-lanceolate, 2.5–3.5 × 0.5–1 mm in flower, 3–4 × 0.7–1.1 mm in fruit, apex acute. Corollas white or pale lilac, 9–14 mm; tube 2–3.5(–4) mm wide, spurs straight, 2–5 mm, much shorter than rest of corolla, abaxial lip sinus 2–2.5(–3) mm, adaxial lip sinus 1–2.5 mm. Styles simple; stigma entire. Capsules subglobular, 3–4 × 2.8–4 mm, glabrous; loculi equal. Seeds gray or black, trigonous or ± tetrahedral, 1.2–1.8(–2) × 0.6–1 mm, with longitudinal marginal ridges and anastomosed ridges, sometimes with tubercles, on faces; wing absent. 2n = 12 (Europe).

Phenology: Flowering Jul–Sep.
Habitat: Roadsides, railroad rights-of-way, waste places.
Elevation: 0–200 m.

Introduced; N.B., Nfld. and Labr. (Nfld.), N.S., Maine, Mass., N.J., N.Y., w Europe.

Discussion

Pre-1900 collections of Linaria repens on ballast are known from New Jersey and New York. Linaria repens is known from an old collection in Nova Scotia and was once collected from St. Pierre and Miquelon; the population did not persist.

Linaria repens is polymorphic, easily recognized by the spur much shorter than the rest of the corolla. Hybrids between it and L. vulgaris (known as L. ×sepium) are relatively common in Newfoundland (see comments under 1. L. vulgaris).

Selected References

None.

Lower Taxa