Agronomist Melani from the Bogor Botanical Garden shows a group of students a gandaria or plum mango and menteng fruits and asks the students to name them.
None of them knows the answer.
"What about the name of this tree?" Melani asks again, pointing out a small plum mango tree. The students again had no idea.
Talking to the group of students from state primary school Cikoneng, in rural Cisarua district, the researchers are dumbfounded as none of the children know the names of indigenous fruits.
The researchers say they are concerned that the students can only name apples and pears, as well as jambu air or rose apple.
The students cannot name local fruits such as buni, menteng, gandaria, and bisbul or velvet apple.
Buni (Antidesma bunius) is a small purple fruit with a tart taste. Menteng (Baccaurea dulcis) has a sweet-sour taste.
Gandaria (Bouea macrophylla) is a yellow fleshy fruit with a sour to sweet taste with a faint smell of turpentine, while bisbul or velvet apple (Diospyros blanchoi) is a dark red to purple fruit with a velvet-like skin.
The researchers say that if children living in a village do not know the names of the fruits from trees planted in their own front yards, the ignorance will be far more acute among children in big cities such as Jakarta.
Many modern children are not familiar with local fruits, the researchers lament, because most of the plants are already extinct in their endemic areas.
As fewer and fewer home gardens boast these trees, people lose their attachment to the plants, which are also considered a natural heritage, the researchers say.
In Jakarta, for instance, most people are not aware that the names of some areas, including Gandaria, Kemang and Palmerah, came from the names of trees that used to be commonly found in those areas.
The coordinator of the conservation class, Bogor Botanical Garden researcher Tri Handayani, says the children took part in planting a mini botanical garden in their school yard earlier in the day.
The trees planted in the school yard are local species.
Tri says the researchers want the schools to be natural laboratories specializing in local fruit.
The children have already planted buni, menteng, gandaria, and bisbul trees, along with jamblang (Syzygium cumini) and gowok (Syzygium polycephalum) trees. Researchers are holding the conservation classes at three of around 30 elementary schools in the Puncak area of Cisarua.
The schools - Gunung Mas, Kopo 3 and Cikoneng - each get 500 plant seeds.
The students receive lessons on environmental issues, plant conservation and an introduction to the names of local fruits, including how to cultivate the fruit trees around their homes.
"We only picked three schools to make the mini botanical garden with local plants, because those schools were the only ones with enough land for a botanical garden," Tri says.
She adds the researchers want to highlight to the students the importance of trees.
The researchers explain that trees can retain water and help make the air fresher.
They also emphasize the need to conserve the upstream area of the Ciliwung River, which originates in Puncak.
The Bogor Botanical Garden uses the water from the Ciliwung River to irrigate its collection of plants.
