Flora of New Zealand Series

tarweed

Viscid herb with erect, often simple stems to c. 60 cm tall. Lvs 1.2-4.5 × 0.5-1.5 cm, lanceolate to narrow-elliptic or oblong, coarsely serrate, with glandular hairs mainly on veins and margin; margins flat; apex obtuse or acute. Infl. becoming > non-flowering part. Upper bracts reduced. Calyx 1-1.5 cm long, mainly glandular-hairy along nerves and margin of lobes; teeth 6-10 mm long, narrow-triangular, green, acuminate. Corolla 17-25 mm long (to apex of upper lip), yellow, ± deciduous; upper lip 6-8 mm long, glabrous inside; lower lip with rounded lobes, lacking glandular concavities, the middle lobe 4-5 mm long. Filaments hairy. Capsule 0.9-1.2 cm long, oblong-obovoid, hairy in upper part. Seeds c. 0.2 mm long, ovate-oblong or ellipsoid.

N.; S.; St.; Ch.

W. Europe, Mediterranean region, Macaronesia 1875

Common to abundant in pastures, especially where damp, roadsides, waste places, lake margins and streamsides, probably parasitising a wide range of plants, although at least sometimes autotrophic.

FL Nov-May.

P. viscosa generally grows in wetter sites than P. latifolia. It has previously been known in N.Z. as Bartsia viscosa and Odontites viscosa.