Description: Annual or perennial herbs.
Leaves on non-flowering shoots at base of plant whorled, leaves on flowering stems alternate and narrower; lamina simple, margins entire, sessile.
Flowers in terminal bracteate racemes or spikes, [or rarely solitary in the axils of foliage-leaves]; bracteoles absent. Sepals 5, often unequal, fused only at base. Corolla 2-lipped; tube cylindrical with a basal spur; upper lip 2-lobed; lower lip deeply 3-lobed with palate usually closing the throat. Stamens 4, didynamous, enclosed in corolla. Stigma simple or divided.
Capsule ± globose, dehiscing by vertical slits in upper half; seeds numerous.
Distribution and occurrence: World: c. 120 species, temperate Northern Hemisphere, especially Mediterranean region. Australia: 6 species (naturalized) Qld, N.S.W., Vic., W.A.
Most species bear at their base short non-flowering shoots; in the annual species these may be hairy when the rest of the plant is glabrous, and bear whorled leaves which are often broader and shorter than those of the flowering stems. The record of L. maroccana Hook. f. in Jacobs & Pickard (1981) is based on cultivated material.
Text by W. R. Barker
Taxon concept:
Taxa not yet included in identification key
Linaria nigricans
| | Key to the species | |
| 1 | Corolla yellow, sometimes with an orange palate; perennials | 2 |
| Corolla violet or purple, sometimes with a white or yellow palate; annuals | 3 |
| 2 | Leaves more or less stem-clasping, usually 5–20 mm wide; sepals mostly 5.5–6 mm long; seeds compressed tetrahedral, 1–2 mm long | Linaria genistifolia |
| Leaves cuneate at base, usually 1–4 mm wide; sepals 2–3 mm long; seeds discoid, 2–3 mm long
Back to 1 | Linaria vulgaris |
| 3 | Corolla 5–11 mm long along the upper side; spur backwards-directed from tube, 6.5–11 mm long; seeds reniform or discoid, without an entire wing | 4 |
| Corolla 2–3.5 mm long along upper side; spur at right angles to tube, 1.5–3.5 mm long; seeds discoid and winged or oblong and angled
Back to 1 | 5 |
| 4 | Inflorescence glandular-pubescent; corolla mouth open; capsule obliquely broad oblong-ellipsoid, 4.5–5 mm long; seeds obliquely reniform, transversely wrinkled, 0.7–0.8 mm long | Linaria incarnata |
| Inflorescence glabrous; corolla mouth more or less closed; capsule symmetrical, with 2 globose lobes, 2.2–2.7 mm long; seeds discoid, more or less circular, 1–1.2 mm long, fimbriate
Back to 3 | Linaria pelisseriana |
| 5 | Corolla 2–2.7 mm long along upper side; spur 1.5–2 mm long; seeds discoid, winged | Linaria arvensis |
| Corolla 3–3.5 mm long along upper side; spur 2.5–4 mm long; seeds oblong, angled
Back to 3 | Linaria canadensis |
|
