Flora of New Zealand Series

Type locality: Warkworth. Type: BD 87351.

Slender many-branched shrub to 3 m. tall. Lvs c. 5·5 × 2 cm., elliptic, entire, tapering to ± acute tip, on petioles c. 1 cm. long; margins slightly recurved; upper surface glab. except for minute hairs in groove of midrib, smooth; lower surface whitish with close sessile short-rayed stellate hairs, only principal veins obvious, long hairs few and simple and on veins only. Infl. a much-branched rather open ± conical corymb up to 10 cm. across; bracts broad, scarious; pedicels c. 4 mm. long. Fls pale, calyx-tube hairs mostly sessile, short-rayed, stellate and crowded, long hairs few and simple; sepals c. 2 mm. long, falling early; petals white, limb truncate to cordate at base, standing erect; stamens > petals, connective produced beyond anther into sharp tip; style divided to < 1/2 length; capsule 3 × 2*5 mm., c. 1/2 immersed in calyx-tube, soon becoming reddish and losing hairs from free part of ovary; operculum c. 1/2 length of coccus; seeds almost black, shining, c. 1·5 × 1 mm.

DIST.: N. Rodney County and near west coast of Firth of Thames; Bay of Islands? Poor clay hills.

FL. 9-10. FT. 11-1.

Seedlings transplanted from Warkworth to the Wellington garden of Dr. W. M. Hamilton have provided fresh material for study at all seasons, and from one of these the type specimen is chosen. The specific name records the long association of the Hamilton family with one habitat of this sp. and their interest in the native plants of the district.

This plant, locally known as "pale-flowered kumarahou", has long been very common in restricted areas; in W is a specimen collected by T. Kirk at Matakana where it still grows. A Bay of Islands specimen, also T. Kirk in W, does not show the well-developed connective tip but otherwise matches P. hamiltonii; no recent collection is known from this district.

P. hamiltonii differs from P. kumeraho in smoother lvs tapering at both tip and base, and with only main veins obvious, in shorter and more even indumentum without long-rayed stellate hairs, in more open infl. of paler-coloured fls, in the sharp connective-tip, in the darker and more shining frs, and in chromosome number. Australian specimens determined as P. multiflora Sieb. ex DC. Prodr. 2, 1825, 33 differ from P. hamiltonii as much as P. elliptica differs from P. kumeraho; in P. hamiltonii fl.-buds and veins of young lvs have many long simple hairs that are lacking in P. multiflora. P. siebeirana N. A. Wakefield in Vict. Nat., Melb. 68, 1951, 140, which is described as having white-villose, calyx-tube, has larger lvs with different indumentum ("Foliis ovato-lanceolatis, ad 8 cms. longis, supra glabris, infra reticulato-venosis in laminibus pilos parvos curvatos in costis petiolisque majores fasciculatos fuscos ferentibus . . ."). These last two spp., like P. hamiltonii, have petal-limb ± auriculate and style little cleft. Relationships to P. intermedia Sieb. loc. cit. and P. discolor DC. Prodr. 2, 1825, 33 remain obscure.