January 2009. A weed from north Queenland, Australia.

It as identified as Barleria lupulina (Acanthaceae). It is often seen as an escaped ornamental in semi-dry or rain shadow parts of islands in the Pacific in Fiji, Solomon Islands, Papua New Guinea, Nauru and New Caledonia.

It is also reported from India. There is also Barleria prionitis, which is commonly found in drier areas of India. Four other species are reported in Bengal Plants without thorns. Barleria lupulina is characterized by red mid-veins and spines, while B prionitis is not.

[Editor: Note, B pronitis is on a Nationl Environmental Alert List: http://www.weeds.org.au/cgi-bin/weedident.cgi?tpl=region2.tpl&rltv=157&seen=10&state=nsw&s=&region=sb].