Kumara Lantana is a beautiful hedgerow plant which is common in Australasia.
I live in the UK and have been searching for a source of seeds for this plant
in order to establish it in my garden.

I had to think for a minute because you had the name slightly messed up. What
you want is Lantana camara. You should be able to buy them from a houseplant
nursery. In this country they are also sold in the North as annuals. Yes. the
inflorescence is an umbel. They belong to the Verbenaceae.
Iris
Iris,
Central NY, Zone 5a, Sunset Zone 40
"If we see light at the end of the tunnel, It's the light of the oncoming
train."
Robert Lowell (1917-1977)