Pittosporum

Pittosporum (or ) is a genus of about 200 species of flowering plants in the family Pittosporaceae. The genus is probably Gondwanan in origin; its present range extends from Australasia, Oceania, eastern Asia and some parts of Africa. Citriobatus can be included here, but might be a distinct (though closely related) genus. They are commonly known as pittosporums or, more ambiguously, cheesewoods.
The species are trees and shrubs growing to 2–30 m tall. The leaves are spirally arranged or whorled, simple, with an entire or waved (rarely lobed) margin. The flowers are produced singly or in umbels or corymbs, each flower with five sepals and five petals; they are often sweetly scented. The fruit is a woody seed capsule, which bursts on ripening to release the numerous seeds. The seeds are coated with a sticky resinous substance. The genus is named after their sticky seeds, from the Greek meaning "pitch-seed".
Tarata (P. eugenioides) and kohuhu (P. tenuifolium) – both from New Zealand – and the Japanese cheesewood (P. tobira) from southern Japan are widely cultivated as ornamental plants in subtropical regions; pittosporums can also be grown indoors as bonsai. The petroleum nut (P. resiniferum) yields petroleum nut oil, which is sometimes proposed as biofuel; due to its excessive n-heptane content and consequent low octane rating, it is better suited as a source of n-heptane, which is otherwise produced from crude oil.
Many herbivores detest the resinous pittosporums, in particular their seeds, which will stick anywhere. But some animals eat them with relish, for example the kea (Nestor notabilis), which likes P. anomalum fruit and seeds. The cottony cushion scale (Icerya purchasi) is a common pest on ornamental pittosporums (in particular the New Zealand species); the sac fungus Nectriella pironii often infects Japanese cheesewood.
Selected species
Pittosporum aliferum Tirel & Veillon
Pittosporum angustifolium
Pittosporum anomalum Laing & Gourlay
Pittosporum arborescens Rich. ex A. Gray
Pittosporum argentifolium Sherff – hōawa
Pittosporum artense Guillaumin
Pittosporum bicolor
Pittosporum bracteolatum
Pittosporum brevispinum
Pittosporum ceylanicum
Pittosporum collinum
Pittosporum confertiflorum A.Gray – hōawa (Hawaii)
Pittosporum coriaceum
Pittosporum cornifolium – tāwhiri karo
Pittosporum crassifolium – karo
Pittosporum dallii
Pittosporum daphniphylloides
Pittosporum dasycaulon
Pittosporum divaricatum
Pittosporum ellipticum
Pittosporum ellipticum subsp. serpentinum
Pittosporum eriocarpum
Pittosporum erioloma
Pittosporum eugenioides A. Cunn. – tarata, lemonwood (New Zealand)
Pittosporum fairchildii
Pittosporum ferrugineum
Pittosporum gatopense
Pittosporum glabrum – hōawa
Pittosporum goetzei
Pittosporum gomonenense
Pittosporum heterophyllum
Pittosporum hosmeri – Kona cheesewood
Pittosporum illicioides
Pittosporum kirkii – Kirk's pittosporum, Kirk's kōhūhū, thick-leaved kohukohu
Pittosporum lancifolium
Pittosporum ligustrifolium
Pittosporum linearifolium
Pittosporum mackeei Tirel & Veillon (Ponérihouen area of New Caledonia)
Pittosporum moluccanum
Pittosporum multiflorum
Pittosporum muricatum
Pittosporum napaliense
Pittosporum nativitatis
Pittosporum obcordatum – heart-leaved kohuhu
Pittosporum oreillyanum – O'Reilly's pittosporum
Pittosporum ornatum
Pittosporum orohenense
Pittosporum paniense
Pittosporum parvifolium
Pittosporum patulum
Pittosporum pauciflorum
Pittosporum pentandrum
Pittosporum phillyreoides – weeping pittosporum, willow pittosporum, butterbush, native apricot
Pittosporum pickeringii
Pittosporum raivavaeense
Pittosporum rapense
Pittosporum rarotongense
Pittosporum resiniferum – petroleum nut
Pittosporum revolutum – rough-fruited pittosporum, wild yellow jasmine, yellow pittosporum, Brisbane laurel
Pittosporum rhombifolium (now Auranticarpa rhombifolia) – Queensland pittosporum, diamond pittosporum, Hollywood
Pittosporum rhytidocarpum
Pittosporum rubiginosum
Pittosporum senacia
Pittosporum silamense
Pittosporum spinescens
Pittosporum stenophyllum
Pittosporum taitense
Pittosporum tanianum
Pittosporum tenuifolium – kōhūhū, kohukohu, black matipo (New Zealand)
Pittosporum terminalioides
Pittosporum tobira (Murray) Aiton fil. – Japanese cheesewood, Japanese mock orange (Japan, China, and Korea)
Pittosporum trilobum
Pittosporum turneri
Pittosporum umbellatum – haekaro (New Zealand)
Pittosporum undulatum – sweet pittosporum, Australian cheesewood, native daphne, mock orange (east coast of Australia)
Pittosporum venulosum F.Muell.
Pittosporum virgatum
Pittosporum viridulatum
Pittosporum viridiflorum
Pittosporum viscidum
Pittosporum wingii
Pittosporum yunckeri A.C.Sm.
References
Apiales genera
Taxa named by Allan Cunningham (botanist)