Begonia phoeniogramma is an herbaceous plant endemic to Peninsular Malaysia. It ranges in height from 13 to 27 cm with graceful flowers at upper terminal. B. phoeniogramma grows on shaded steep earth slopes and also on the surface of granite rocks or limestone in the lowland forest of the state of Selangor. Most begonia species have attractive leaves with less showy flowers or vice versa. But B. phoeniogramma has both striking leaves and attractive flowers.

B. phoeniogramma has unequal heart-shaped leaves attached to translucent reddish brown stems. The variegated leaves have distinct leaf color and patterns that vary between different populations. One particular variant is fascinating because although the leaves are a plain dark green color, they have a metallic sheen which makes the leaves appear to change colour when viewed under different levels of shade and from different viewing angles. The perceived colour can range from green, through bluish, purplish and even brownish. This polychromatic effect is a remarkable phenomenon and deserves further investigation.

B. phoeniogramma is also known as the Red Striped Begonia due to its red-veined flowers. This characteristic is useful to distinguish B. phoeniogramma from another similar succulent begonia – B. integrifolia. Like other begonias, the Red Striped Begonia is a monoecious plant, having separate male and female flowers on the same inflorescence. The male flowers usually bloom before the female flowers; it is only when most of the male flowers have wilted and dropped, that the female flowers are ready for pollination. This natural rhythm encourages cross pollination, increasing the probability that pollen from another plant will be the first to fertilize the female flowers.

Begonia species are considered highly vulnerable to extinction in the wild because most begonias are not adapted to direct sunlight and high temperature environments that result from deforestation. Although B. phoeniogramma is distributed in several forest reserves in Selangor, we need to account for the rapid population growth and the frenzied pace of development in the state when assessing threat and planning conservation measures.

The Red Striped Begonia no doubt has strong potential as an ornamental plant due to its pretty leaves and flowers. Efforts to keep several variants of this begonia species for ex-situ conservation and domestication introduction are ongoing in FRIM’s nursery. Based on observation, B. phoeniogramma in the wild becomes physiologically dormant during the dry period which normally lasts from the end of November to March. But young plantlets from leaf cuttings that were kept in a humid and shaded location did not show signs of dormancy. However the plantlets seemed to grow relatively slowly during the dry season which may indicate that mechanisms other than current environmental stimuli are involved. This phenomenon needs to be studied further to determine what, if any, mechanisms are at work.

Reference:

Kiew, R. 2005. Begonias of Peninsular Malaysia. Natural History Publications (Borneo) Sdn. Bhd. & Singapore Botanic Gardens.

By Joanne Tan Pei Chih
e-mail: joannetan@frim.gov.my