This article was published in the Titirangi Tatler, October 2010
Pomaderris kumeraho - kumerahou or gumdiggers soap.
The dry, barren road-side banks of West Auckland used to come alive in spring. Where for 11 or more months of the year there was nondescript shrubbery, for just a couple of weeks there was a glorious display of the golden flowers of kumerahou. To the observant, there had been a slow evolving development since the previous summer as the flower buds of kumerahou slowly swelled.
During September/October kumerahou plants would all flower simultaneously in 2 or 3 short weeks, producing extensive drifts of gold. The flowers would then shrivel before swelling again to produce the seed capsules which would release the fertile seeds between Xmas and New Year. Almost immediately the next cycle would start with fresh flower buds beginning to show on new growth.
Of course nature still ordains the cycle should continue with the rhythm of the seasons, but today there is not the same intense flowering that was formerly so remarkable. Lucy Cranwell, in her 1936 book "Botany of Auckland", refers to kumerahou as ‘poverty weed' because it was once so common on poor soils, and says it was the springtime glory of more open areas, lighting up the landscape with its massed flowers, the pure colour of sulphur.
Alas, such displays are rare today as weeds displace poor kumerahou and stifle their seedlings, a far cry from Lucy's observation that carpets of seedlings used to grow so thickly that thousands of them would die from lack of room and nutrients. Now the weeds don't let them even germinate.
A few years ago a move was started by enthusiasts to assist the recovery of patches of kumerahou on selected roadsides, but it seems their enthusiasm has waned and the weeds are taking over once more. The golden curse of gorse may be brighter, but we all need to help re-establish kumerahou on the verges and banks of West Auckland. Why not make it a New Year's Day resolution? Collect the seed and redistribute it along suitable sunny clay banks near you and your springtimes will be the brighter for it.
Having a supply of kumerahou nearby is useful as early kauri gumdiggers discovered. When the sticky resin of kauri stains the hands, there is no better handcleaner than a few crushed and moistened leaves of kumerahou. Today the frothy potion created when the leaves are rubbed between the hands is more effective than powerful soaps or detergents in removing engine oil and other nasty chemicals.
Herbalists have claimed other attributes for kumerahou and its curative properties were once renowned.
There are also other species of Pomaderris, occurring for the most part north of the Bay of Plenty. They do not have the same blaze of golden flowers, but each species is attractive in its own special way. One or two are now included on endangered species lists as being threatened with extinction due to the lack of habitat and competition from weeds.