Plagianthus regius subsp. chathamicus

Detailed description

Deciduous, dioecious, rounded or flat-topped trees 10−16(−18) m tall. Trunk up to 1 m d.bh., bark smooth, if torn peeling in long fibrous strips; surface brown-grey to grey, colour usually obscured by dense lichen growth (Amandinea, Bacidia, Lecanora, Pyrenula, Ramalina and Xanthoria species especially). Branches divergent to upright, often densely branched; branchlets, terete, pliant when young, brittle with age, if broken, leaving long tears of bark beyond damage point; initially finely pubescent, pubescent-villous, hairs grey-white, ± patent, hairs shedding with age. Buds, solitary, acute, densely covered in pubescent-villous, grey-white hairs; bud scales valvate (3−)4−5, (0.4−)0.6−0.8 mm long, deltoid, ± subulate, abaxially pubescent-villous, caducous. Leaves exstipulate, alternate distichous, ± closely spaced toward branchlet apices, soft and pliant, somewhat chartaceous with pinnate venation, surfaces finely pubescent when young, hairs shedding with age, ± glabrescent, adaxially light lime green to green, abaxially paler; midrib concolorous with lamina adaxially, paler beneath, not or scarcely raised above, distinctly so abaxially, finely pubescent, indumentum shedding in irregular patches with age; petioles, 15−20(−25) mm long, terete, finely pubescent, glabrescent. Lamina of juvenile 40−70(−80) × 26−34(−40) mm, of adult 70−90(−100) × 40−60(−65) mm; ovate, ovate-deltoid, apices acute to acuminate, base obtuse to subcordate, biserrate. Inflorescences axillary or terminal, borne in much-branched, suberect or pendent, compound, cymose panicles (65−)100(−140) × 80−100(−160) mm long, green to yellow green. Inflorescences axis terete, initially pubescent, indumentum shedding with maturity, leaving sparse to dense patches of patent hairs; branch axis, bracteate, bracts 3−5 × 3−6 mm, caducous, ovate-deltoid, deltoid, acute, surfaces finely pubescent. Flowers 5−6 mm diameter: ♂ yellow-green or greenish-white, sweetly scented; ♀ light green, without scent. Calyx campanulate to funneliform, 1.8−2.0 mm long, pale green or yellow-green, with 5 deltoid or oblong, acute or mucronate teeth. Petals 2.4−2.8 mm long (♂), 2.0−2.4 mm long (♀), spathulate-oblong, oblong, clawed, yellow-green, greenish-white or green, shedding after anthesis. ♂ with exserted staminal column, anthers 10−12, 0.3−0.5 mm long, sessile, pale yellow or yellow-orange, gynoecium vestigial, surmounting column. ♀ with androecium vestigial, forming a ring below stigma; stigma (3−5)−6, spreading, greenish. Fruits usually exserted from persistent calyx, 3−5 mm long, ovoid, apex acute.