Thursday, April 30, 2009

Green Bollygum

Neolitsea australiensis
The fruits of green bollygums are early this year at Ravensbourne, beginning to ripen already. They are showy dark red, ripening to black, and look rather like giant versions of fruit of the closely related camphor laurel tree. They are highly nutritious and very attractive to birds, making this one of our best species for planting in bird-friendly gardens.
Only the female trees have the bird-attracting fruits, so it is worth planting a number of them, to be sure of a mix of the sexes
Bollygums are fast-growing small, slender trees, which like to grow in the understorey of dry rainforests. We have two local species. Green bollygum is happiest on red soil where it will get little or no frost. (Its cousin the white bollygum, Neolitsea dealbata, grows on a wider range of soils, and is hardier to both frost and drought. It can be distinguished from green bollygum by the hairiness of its young leaves.)
The virtue of understorey plants in gardens is that their roots co-exist happily with the roots of other trees, so they are good for planting under established trees or in shrubberies and rainforest-style gardens, where close planting is the go.

When new, green bollygum’s leaves are very distinctive ornamental purplish-green, and hang limply. As they mature, they become shiny green, with a pale greyish-white waxy bloom on their backs. Young plants have particularly large, showy leaves.

 This is a plant which likes fertile soil, and appreciates a good layer of organic mulch.

Green bollygum is one of the plants that is unable to germinate near its vigorous, introduced relative the camphor laurel tree. In an ideal world, we would be taking care that these invasive weeds are never allowed to escape into the shrinking remnants of the bollygum’s existing habitats, as they could cause its extinction. The hope that bollygums will continue to exist in the wild, a few hundred years from now, may be a vain one. Camphor laurels have been spreading in the bushland here ever since they were introduced as an ornamental plant more than a century ago. Though they spread more in our district than they have in coastal habitats, it may be inevitable that this single species will eventually take over from the eighteen or so of its laurel-family relatives which now grace our rainforest habitats.

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