You make me curious David.
Hi Luit,
It has taken a few days to answer your queries about Acaenas so I hope you find this posting will satisfy your curiosity.
First is a picture of Acaena novae-zelandiae growing wild on my property - It would make a good ground cover if you have a lot of ground to cover otherwise it does not have much merit as a garden plant. It is currently growing up through a metre high netting fence in my garden. Similar species are Acaena pallida, Acaena anserinifolia and Acaena juvenca, the later growing under trees in light shade.
Next Acaena caesiiglauca This has lovely blue-green foliage. Unfortunately it has barbed spines on the seeds. My potted specimen was a bit ratty so here is a picture of a wild plant.
3 is Acaena saccaticupula It is subalpine and has blue-green foliage and spectacular red seed heads.
4 I have labelled Acaena Red spines A very attractive vigorous plant.
5 is a green- foliaged form of Acaena inermis. Acaena inermis has no spines on its seed so is a good garden plant. There are also purple and bronze forms.
6 This is a form I have tag named Acaena Maitland. It has attractive foliage though the colour has changed since I collected it. It is possibly a form of Acaena dumicola.
7 This Acaena microphylla var pauciglochidiata. It is a tiny creeping plant The seed heads are very small and are hidden by the foliage. The leaves have purple margins
8 is Acaena buchananii var picta. This is a form selected originally by Lawrie Metcalf. It has very unusual coloured foliage.
This is ony a fraction of the different forms and species found in the wild. The plants can be propagated easily from cuttings.