I've been growing acumintas for quite some time now and all of my seeds came from an ebay seller (not communication) from WA.
Anyway I purchased both narrow and broad phyllode seeds (a few people thought I was mad when they heard I was growing the narrow phyllode variety - it was that long ago) and planted them all and kept them separate. The plants grew out & for all money looked true to the genotype from the morphology of the phyllodes.
So now they have all flowered for a few years and produced seed I'm starting to wonder if there could have been a mix up somewhere along the line.
All of the trees have grown out to produce the typical narrow phyllodes through multiple seasons of growth under all conditions but there has been some wide ranging differences in the morphology of the seed and pods the trees have produced.
Some of the trees have have grown shorter fatter pods with larger seeds and others have grown long thin pods with the expected smaller seeds. A few others have grown long pods with large seeds.
To confuse the issue further I also have trees grown from tubestock I purchased with broad phyllodes that seem to be a small seed variety with seeds and pods approx. the same size as the (apparently) narrow phyllode specimens.
I don't want to name the ebay seller as it is possible that I have mixed the plants up at one stage, although I don't believe this is the case - I had the plants in separate locations the whole time from sowing to planting out.
Hybridisation could be a factor here, maybe the seed parents were erroneously identified on the phyllode morphology alone or pollen was transferred from a nearby stand of broad phyllode acumiatas. Or maybe the few broad phyllode trees I have planted nearby have pollinated the narrow phyllode variants.
So after many visits to world wide wattle over the last 2 years, I have 1 in 4 trees trees that I could say with any confidence are expressing the traits of the typical garden variety narrow phyllode acuminata with many impostors lurking in the shadows.
Maybe some of our WA members have some more experience with these, I've got heaps of seed to share but I don't want perpetuate a fallacy.