Veronica hookeriana Walp.

Low sub-shrub to 0.2 m tall, sometimes a loose cushion or mat. Stems prostrate to ascending, usually eglandular-pubescent, rarely glandular as well; hairs bifarious to uniform. Leaf bud indistinct; leaves separating while very small, opposite-decussate, sub-distichous on prostrate stems, erecto-patent to reflexed; lamina sub-coriaceous, ovate, elliptic, obovate, orbicular or rhomboid, rarely lanceolate or oblanceolate, 3–14 mm long, 2.5–10.0 mm wide, dull green, dark green or bronze-green above, pale beneath; midrib and rarely 2 lateral veins evident; surfaces glabrous or hairy above and sometimes also beneath with eglandular and sometimes also glandular hairs; margin glabrous or ciliate, bluntly serrate to crenate; teeth in 1–4 pairs; apex obtuse, rounded, or sub-acute; base cuneate or abruptly cuneate; petiole 1–3 mm long. Inflorescence a lateral raceme, 30–110 mm long; flowers distant, 3–15, all bisexual; bracts alternate, lanceolate to elliptic or deltoid, < pedicels; pedicels erect or erecto-patent, sometimes incurved at fruiting, 3–18 mm long, eglandular- to glandular-hairy all around. Calyx lobes 4, sub-acute to obtuse, 2–3 mm long, sub-equal, ciliate to pubescent with eglandular and often glandular hairs. Corolla 9–15 mm diameter; tube white and greenish-yellow, 1.0–1.5 mm long, < calyx, eglandular-hairy inside; lobes 4, purplish or pink, sub-erect to spreading, unequal, elliptic to obovate or orbicular, 4–7 mm long rounded or sometimes posterior lobe emarginate to divided; nectar guides magenta. Stamen filaments white or pink, 4–6 mm long; anthers purplish to pink or magenta. Style glabrous, 4.0–5.5 mm long. Capsules angustiseptate to turgid, truncate to emarginate, glabrous, 3–6 mm long, 3–5 mm at widest point. Seeds discoid to ellipsoid or obovoid, flattened, smooth, pale to dark brown, 0.8–1.5 mm long.

Among the speedwell hebes (a group characterised by lax inflorescences, short corolla tubes, corolla nectar guides, attenuate stamen bases, turgid or weakly angustiseptate capsules and often plicate lateral corolla lobes), V. hookeriana plants are quite distinctive but at times can be confused with other species.

The distribution of V. lanceolata overlaps with that of V. hookeriana and the two sometimes grow together. V. lanceolata plants are sometimes prostrate like V. hookeriana, but more often are sub-erect to erect, have corollas that are white with magenta nectar guides, sharper teeth and apices on leaves, and usually fewer hairs on leaves and inflorescences. However, V. hookeriana plants with paler flowers and narrower leaves that are glabrous may be difficult to distinguish from small plants of V. lanceolata (e.g., on Hikurangi, Raukūmara Range).

North Island records of V. lyallii have been based on misidentifications of V. hookeriana or small plants of V. lanceolata. V. lyallii plants usually have smaller and glabrous leaves, inflorescences that have shorter, usually eglandular hairs, white flowers, and smaller seeds.

Sub-alpine to alpine open sites: screes, fell-fields, banks, rock outcrops. Recorded elevations range from 914 to 1750 m.

Plants of V. lanceolata in areas where it comes into contact with V. hookeriana are often more glandular and prostrate, with smaller leaves. This might be a result of introgression, or it could be an independent adaptation to alpine environments. In support of the latter interpretation, I note that alpine forms of V. lanceolata on the Tararua Range, where V. hookeriana is absent, also display this trend. Ashwin (in Allan 1961) noted that the population at Maungapohatu is extremely variable and suggested hybridisation with V. lanceolata (as Parahebe catarractae) is the reason.

Flowers: November–March; fruits: February–May, persisting all year.

2n = 42, 84 (Hair 1970), as Parahebe hookeriana var. hookeriana and var. olsenii; however, both voucher specimens are now considered to match var. hookeriana (Garnock-Jones & Lloyd 2004), and the Ruahine Range form named as V. olsenii by Colenso is still cytologically unknown.

Veronica hookeriana is classified in V. subg. Pseudoveronica sect. Hebe and informally in the “speedwell hebe” group (Albach & Meudt 2010).

There is considerable variation within the circumscription of V. hookeriana. Ashwin (in Allan 1961) described six regional races, as summarised in Table 9 and applied existing names to two of these, at varietal rank.

(See: Regional variation in Veronica hookeriana)

Analyses of both nuclear and chloroplast DNA sequences place V. hookeriana firmly in the speedwell hebe clade but provide no well-supported hypotheses of its more immediate relationships.

Seed dimensions of 1–3 mm long given by Garnock-Jones & Lloyd (2004) appear to be based on a measurement error.