Alphitonia excelsa (RHAMNACEAE) Red Ash, Soap Tree

Plants to Plant

A small to medium tree to 18 m in open forest and in the transition zone between dry rainforest remnants and eucalypt forest. A early coloniser of disturbed dry rainforest and a fast-growing, good pioneer species. The undersurface of the leaf blade is silvery white. The leaves frequently look tatty after being ravaged by various leaf chewing insects which in turn are eaten by many native birds. Cream-green flowers November-March. Fruit a dull black, globular drupe. Powdery red flesh covers two hard cells each containing a single seed. Seed needs to be scarified to propagate, or try cuttings which strike well.

Leaf under surface. Photo: Robert Whyte

Flowers and Young Fruit

Alphitonia from Greek alphiton, barley-groats, a baked barley meal, referring to the mealy red covering around the hard cells in the fruit. Excelsa from Latin excelsa elevated, lofty or high because of its tall habit. Aborigines used crushed leaves and berries as a fish poison. Its saponin produces a soapy foam which acts to break down water tension and deoxygenate pools, stunning fish. Leaves were crushed, mixed with water and applied as a head bath to reduce headache and sore eyes. Infusions of the bark and root were rubbed on bodies to reduce muscular ache or gargled to cure toothache. The pharmacology of its action seems related to anti-inflammatory chemicals.

Photo: Robert Whyte


Alphitonia excelsa has many common names include Soapwood, Mountain Ash, Leather-jacket, Coopers Wood, White Myrtle, Foambark, Mel-a-mee, Sarsaparilla, Red Almond, Humhug, Ane, Murrung, Nono Gwyinandie, Culgera-cul-era and Coraminga. This is an indicator of its extensve human use.

Photo: Robert Whyte

Host Plant

Host food plant for Fiery Jewel Hypochrysops ignita a butterfly with a wingspan of about 3 cm. Underneath they have patterns like flames (yellow with scarlet bands outlined in black, white and iridescent green). This is probably is the reason for their scientific name, derived from ignis, the Latin word for fire. There are also three or four black spots under each forewing. Host also to Blue Jewel Hypochrysops delici, Indigo Flash Rapala varuna simsoni and Small Green-banded Blue Psychonotis caelius taygetus.

Flowers. Photo: John Abbott

Alphitonia petriei

Another Alphitonia commonly planted in rainforest gardens (not a local Enoggera species) is Pink Ash Alphitonia petriei, said to be smaller, but often a larger tree than the A. excelsa in cultivation. It is endemic to Australia, found in Queensland and NSW, and in some situations might be useful as a pioneer.

Alphitonia petriei. Photo: Robert Whyte