Two plant species with extremely small populations bloomed for the first time in the Kunming Botanical Garden, southwest China's Yunnan Province, marking great success of the ex situ conservations for the two species.

Erythropsis kwangsiensis (Sterculiaceae), a plant species endemic to Guangxi Zhuang Autonomous Region, is under second-class national protection in China. It grows bright red flowers comparable to a burning torch. The plant has high ornamental value and is regarded as a desirable option for urban landscaping.

The fragile ecological environment in the main distribution areas of the species has led to its small population size.

"Affected by the fragile ecological environment in limestone area, the species' habitats have degenerated dramatically. As a result, it has relatively small population and there is low survival rate of seedlings in the wild," said Li Congjia, a postgraduate student in the Kunming Institute of Botany under the Chinese Academy of Sciences.

Magnolia phanerophlebia (Magnoliaceae) grows in tropical and subtropical forests. It is more than three meters high, with evergreen leaves and white flowers. There are five plants of this species in the Kunming Botanical Garden, which were planted in 2008 and bloomed this year for the first time.

The species is only scattered across the southern part of Yunnan Province, with a very limited distribution area and a very small population size.

"Maybe it has encountered some obstacles during pollination. It is difficult for the species to expand its own population without bearing fruits. Another reason is that it grows in low altitude areas where human activities are frequently seen. People plant banana or rubber trees there, which is very harmful to its habitat," said Liu Detuan, an engineer in the Kunming Institute of Botany under the Chinese Academy of Sciences.

Ex situ conservation, namely off-site conservation, is a protective measure to avoid extinction of many species which failed to reproduce themselves independently due to changes in or damage to their natural environment. Researchers and scientists collect the germplasm resources of the endangered plants and take them to the garden. Hopefully the plants will survive and reproduce in a more favorable environment.

Currently, there are totally 51 kinds of wild plants with extremely small populations under ex situ conservation in the Kunming Botanical Garden.