Pittosporum (/pɪˈtɒspərəm/[2] or /ˌpɪtəˈspɔːrəm, -t-/[3][4]) is a genus of about 250 species of flowering plants in the family Pittosporaceae.[1] The genus is probably Gondwanan in origin; its present range extends from Australasia, Oceania, eastern Asia and some parts of Africa. They are commonly known as pittosporums or, more ambiguously, cheesewoods.

Pittosporum
Pittosporum heterophyllum
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Asterids
Order: Apiales
Family: Pittosporaceae
Genus: Pittosporum
Banks ex Gaertn.[1]
Diversity
c. 250 species
Synonyms[1]
  • Citriobatus A.Cunn. & Putt.
  • Cylbanida Noronha ex Tul.
  • Glyaspermum Zoll. & Moritzi
  • Ixiosporum F.Muell.
  • Pittosporoides Sol. ex Gaertn.
  • Pseuditea Hassk.
  • Quinsonia Montrouz.
  • Schoutensia Endl.
  • Tobira Adans.

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

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Pittosporum moluccanum
 
Fruiting branch of weeping pittosporum (Pittosporum phillyreoides)
 
Pittosporum moluccanum
 
Japanese cheesewood (Pittosporum tobira)

References

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  1. ^ a b c "Pittosporum Banks ex Gaertn". Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 13 September 2024.
  2. ^ "Pittosporum". Merriam-Webster.com Dictionary. Merriam-Webster. Retrieved 2016-01-22.
  3. ^ The first pronunciation is that expected for Anglo-Latin; the second is common in nurseries. Sunset Western Garden Book, 1995:606–607
  4. ^ "Pittosporum". Dictionary.com Unabridged (Online). n.d. Retrieved 2016-01-22.