Thursday, June 22, 2006

Episcopal Church to Select Official Flower?

Orchid Does 360-Degree Twist to Self-Pollinate
An orchid growing in harsh conditions defies gravity to twist its male sexual organs 360 degrees to fertilize its female organ, Chinese scientists have discovered.

The pink-flowered orchid, Holcoglossum amesianum, grows on tree trunks at altitudes of 1,200 to 2,000 metres in China's Yunnan province.

The plant flowers during the drought season from February to April, when there is no wind.

Under such conditions, the plant can't use the traditional means of mating used in flowering plants, such as relying on insects or other animals, wind, or gravity to carry the pollen.

In Thursday's issue of the journal Nature, LaiQiang Huang of the centre for biotechnology and biomedicine at Tsinghua University in Shenzhen, China, and colleagues report what they say is a new type of self-pollination mechanism.

[…] "Without pollinators for outcrossing, the necessity of ensuring reproductive success must outweigh the potential adverse effects of inbreeding," the study's authors concluded.

"The present self-contained pollination mechanism is likely to be an adaptation to the orchid’s dry and insect-scarce habitat, and may be widespread among species growing in similar environments."

[…] the pollen-bearing anther uncovers itself and rotates through 360 degrees to insert pollen into its female cavity, the stigma.