Titin and her husband Pak Waki live along a river in central Jakarta. Their business is a small clapboard eaterie on the riverside path. The path cuts straight through their home.
"Just pluck the petals from the vine and drop them in hot water for five minutes," continues Titin.
"Like making a cup of tea?"
"Exactly. Then hold the sodden petals over the baby's eyes and let the blue water drip into them. It makes their eyes bright and clean, and is best used when the baby is between one week and one month old."
"Here, try growing your own," says Pak Waki, holding out a small plastic bag containing six round black seeds. "Many people don't understand the properties of bunga telang: you can't find these flowers in the market, only in people's gardens."