Pittosporum virgatum

Pittosporum virgatum is a species of plant in the Pittosporaceae family. It is endemic to New Zealand.

Pittosporum virgatum
Scientific classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Asterids
Order: Apiales
Family: Pittosporaceae
Genus: Pittosporum
Species:
P. virgatum
Binomial name
Pittosporum virgatum

BRIEF DESCRIPTION

Slender small tree with whorls of branches and variably shaped leaves that are covered in rusty fuzz when young inhabiting inhabiting the northern North Island. Flowers pink to purple. Leaves wavy, edge smooth or often lobed. Capsule splitting into two to show the black sticky seeds.

DISTRIBUTION

Endemic. New Zealand, North and Great Barrier islands, from the Mangamuka and Herekino Ranges south and east to Great Barrier and the Coromandel Peninsula. Reaching its southern limit at about the Kauaerange Valley (there are unconfirmed reports of its occurring slightly further south of there).

HABITAT

Usually associated with kauri (Agathis australis) forest, often on ridge lines, slips scars or in secondary regrowth within cut over kauri forest. Outside this forest type it is occasionally found in association with tanekaha (Phyllocladus trichomanoides), towai (Weinmannia silvicola) or kamahi (Weinmannia racemosa). In all situations it prefers relatively open vegetation, where it typically forms apparently evenly-aged cohorts.

FEATURES

Slender gynodioecious trees up to 8 m tall. Growth form initially narrowly columnar, becomign more spreading with age. Trunks slender grey brown, branches in distinct whorls in old specimens confined to the upper portion of the tree, bark brown, branchlets slender, pliant, brown at first covered with appressed rust-brown tomentum, soon glabrate. Petioles 1-7 x 0.5-1 mm, hairy. Leaves crowded toward branchlet ends, alternate; juvenile or lower leaves 10-40 x 1-7 mm, dark green or yellow-green, linear, entire or variously lobed, sometimes pinnate, both surfaces initially covered in rust-brown tomentum, soon glabrate; intermediate leaves 13-55 x 9-30 mm, lanceolate, narrowly linear, oblong or obovate, usually lobed or deeply divided both surfaces covered in rust-brown indumentum, soon glabrate; adult leaves 18-70 x 4-30 mm, oblong, oblanceolate, sometimes linear or linear-lanceolate, elliptic oblong, entire or sinuate, often lobed; margins flat to undulate. Flowers in 1-6-flowered, terminal fascicles, or solitary. Pedciels 5-9 mm, accrescent in fruit, covered in rust-brown indumentum, subtended by an approximate whorl of leaves, and 1-3 rust-tomentose caducous scales. Sepals 3.5-6.5 x 1-2.5 mm, oblong or linear-lanceolate, acute, rusty-brown tomentose. Petals 6-13 x 2-3 mm, linear-oblanceolate to linear-oblong, acute, fused in a tube for half of length, tips reflexed, dark red, purple, pink, white or golden yellow; stamens 4-7 mm, anthers sagittiform or oblong-ovate, ovary 2-4 x 1-2.5 mm, rusty-brown tomentose; style 1-5 mm, stigma capitate and obscurely 2-4-lobed. Capsules 11-16 x 10-13 mm, 2(-3)-valved, subglobose to subpyriform, apiculate, coriaceous. Mucilage bright yellow to orange-yellow. Seeds 1-16, dull black of irregular shape.

SIMILAR TAXA

The combination of the narrowly columnar to openly virgate growth form, widely spaced whorls of slender branches, extremely variable juvenile, intermediate and adult foliage types (often present on the one mature tree), and rusty-brown tomentose branchlets, leaves, and capsules are unique to this species. It could not be confused with any other.

FLOWERING

September - November

FLOWER COLOURS

Red/Pink, Violet/Purple

FRUITING

July - August (may be present all year round)

PROPAGATION TECHNIQUE

Easily grown from fresh seed which takes between 6 and 12 months to germinate. Can be struck from semi-hardwood cuttings. A beautiful species that is ideal as a specimen tree.

THREATS

Aside from Great Barrier Island where this species is abundant it appears to have always been a sporadically occurring local species of northern kauri dominated forests. While its current distribution suggests that it is biologically sparse, it is vulnerable to possum browsing and some populations were probably lost or reduced by kauri logging. Recent observation sin some parts of Northland that had been regarded as mainland stronghold suggest that this species is now seriously threatened. Pittosporum virgatum is likely to receive a higher threat listing in the near future.

ETYMOLOGY

pittosporum: Pitch seed

References
  1. de Lange, P.J. 1998. Pittosporum virgatum. 2006 IUCN Red List of Threatened Species. Downloaded on 23 August 2007.


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