Yep, a scatological post. Number two in the four part series featuring plants from our Hampton Court Palace Flower Show garden. This time is an Emu Bush, the Poverty Bush, or if you like, the Tar Bush.
Also known a little more formally as Eremophila glabra, the Common Emu Bush, is indeed spread far and wide in the poo of emus. They eat the fruits, digest away the outer coating and then deposit the seed here and there (far and wide) to disperse this beautiful grey bush with colourful flowers.
So this is a species that shouldn't become invasive in the suburbs of London, unless squirrels acquire a taste for the small fleshy fruits. But then eremophilas such as this one are also called Tar Bush because they are sticky to touch and can smell like tar - not the kind of plant I think a squirrel enjoys foraging from.
Most emu bushes grow in dry, inland areas of Australia, where they acquired another of their common names, the Poverty Bush (the botanical name, 'eremophila', also means desert loving). They grow in tough farming country, places where it's a struggle to make a living, and where any plant edible to stock is welcomed.
These are also places where sheep fart, as they do elsewhere. Some recent research out of the University of Western Australia, suggests planting more emu bush might solve global warming. Well not quite, but when part of a mixed diet (e.g. with oat chaff) feeding sheep with Eremophila glabra can reduce methane production (from farting and burping) while maintaining productivity.
The researchers imitated a sheep's stomach by fermenting various plants, then measured how much methane was produced. If Common Emu Bush was part of the mix, emission of the greenhouse gas methane could be reduced by nearly half. Nothing to sneeze at. As a bonus, feeding sheep emu bush might also help prevent lactic acidosis, a form of indigestion, in sheep.
Eremophila is not just attractive to emus and sheep. The flowers are pollinated by various (flighted) birds and insects, depending on their shape and colour. And there is plenty of variety. There are more than 200 species of Eremophila, all of them only found in Australia, with maybe another 70 waiting to be described.
While a pretty plant in the UK summer and tolerant of moderate frosts, it seems the Common Emu Bush will need to be taken indoors for winter if you live in London. When outside, try a sunny position in a well-drained soil.
In any country, the grafted specimens are definitely easier to grow. The root stock is usually Myoporum, the Australian boobialla, a genus that didn't make the cut for our July 2014 show garden.
Images are from central Australia, mostly taken in Olive Pink Botanic Garden, Alice Springs (the source of the wire emu sculpture too). The first emu bush I thought might be Eremophila glabra but astute and knowledgeable reader from Western Australia, Dave Bright, tells me it is Eremophila maculata (possibly var. brevifolia, which has short, rounded leaves). The flowers of Eremophila maculata have a long curved stalk rather than no stalk at all, as in Eremophila glabra. See also my posts on Eremophila gibbifolia and Eremophila debilis.