Also called "winter cherry", abutilon megapotamicum is a species native to Uruguay, Brazil and Argentina. The shrub I spotted in Sanjiv's garden is about 2 metres in height. The leaves are dark green, palmate, with a heart shape at the base. The buds resembled a fat red paper lantern. The fully-bloomed flower had five petals, these are actually enlarged sepals that have fused together to envelop the forming fruit. The fruit, resembling a cherry tomato., had a shiny skin , its flesh embedded with a rich harvest of seeds.
Some scientific details: