Linaria bipartita

Annuals, not reproducing vegetatively by stolons. Fertile stems erect, 8–65 cm; sterile stems to 11 cm. Leaves of fertile stems: blade linear to linear-oblong, flat, 5–57 × 0.5–3.5 mm, apex acute or obtuse. Racemes 1–35-flowered, lax or ± dense in flower, lax in fruit, rachis glabrous or sparsely glandular-hairy, hairs 0.1–0.3 mm; bracts linear to linear-lanceolate, rarely lanceolate, 4–8 × 0.5–2.5 mm. Pedicels erect, 1–7 mm in flower, 2.5–9 mm in fruit. Calyx lobes lanceolate, 3–5 × 0.7–1.5 mm in flower, 3–6 × 1–2 mm in fruit, apex acute or subacute. Corollas purple, mauve, or violet, usually with yellow palate, 17–24 mm; tube 2–3.5 mm wide, spurs straight or curved, 8–14 mm, usually longer than rest of corolla, abaxial lip sinus 0.7–1.5 mm, adaxial lip sinus 1.5–3.5 mm. Styles 2-fid; stigma with 2 discrete areas. Capsules oblong-ovoid, 4.5–7 × 3.8–6.3 mm, glabrous or sparsely glandular-pubescent; loculi equal or subequal. Seeds dark gray to black, reniform or subtrigonous, 0.5–0.7 × 0.3–0.5 mm, with ± conspicuous transverse ridges; wing absent. 2n = 12 (Africa).

Phenology: Flowering Apr–Sep.
Habitat: Waste ground, roadsides.
Elevation: 0–1200 m.

Introduced; Que., Ariz., Calif., N.J., Va., n Africa (Morocco)

Discussion

Glabrous plants (without hairs on the inflorescence axis, calyx bracts, and pedicels) are included in Linaria bipartita. This is the main feature to distinguish it from L. maroccana in absence of mature fruits. Single collections have been found that include both glabrous plants and ones with sparsely hairy calyces and pedicels on the same sheet (for example, New Jersey, Somerset County, Watchung, 11 July 1931, Moldenke 1900, NY), suggesting that L. bipartita may be polymorphic with respect to this feature.

Some specimens of Linaria bipartita have been reported as L. incarnata (Ventenat) Sprengel, which is easily separable from L. bipartita by its densely hairy inflorescences [multicellular glandular hairs (0.1–)0.3–1 mm, with purple to violet transverse walls]. At present, there is no specimen evidence of L. incarnata occurring in North America.

Selected References

None.

Lower Taxa