Gardening with Georgia

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Lotus Land

Wed, Jul 28, 2010 at 12:50:57 PM

Little wonder the lotus is a sacred flower in parts of the world. The Bali Red that opened at home yesterday is exquisitely proportioned and delicately colored. We acquired seeds from a gardening friend, and followed his instructions.


Bali Red on its first open day.

Seeds were scarified with a metal nail file and soaked in water for days in the kitchen window until the first leaf began to emerge. They were tenderly planted in aquatic soil mix but not put in the pond. Instead, we have them growing in large ceramic bowls. All last year, the tubers grew and sent up marvelous round leaves. Over winter, the leaf size shrank back but the plants didn’t die during all that cold. All along, they were given aquatic fertilizer tabs.

Now, the first flower has made the long wait worthwhile, blooming as predicted in its second year. And not only is it lovely, it is biologically interesting as well: the flower heats up to attract its beetle pollinators.

The first day, nine stigmas showed that they were receptive by glistening as the petals opened. By


Glistening yellow dots are receptive
stigmas seen as the flower opens.

early afternoon, the flower closed. In nature, this closure traps beetles inside, where they warm up and mate. This morning, on the second day, the petals opened more broadly, showing the pollen being released by the stamens. Should beetles have been inside, they would have emerged covered in pollen to carry to the next hot flower.

There are other flowers that heat up to attract pollinators. Cycads heat their cones and release sweet beetle-attracting scents. Plants in the aroid family, such as Philodendron selloum, heat their spathe when the female flowers on the spadix are receptive to pollination. Ditto magnolias, water lilies, aristolochias, some palms and members of the Panama hat plant family.

In 1997, Roger Seymour and Paul Schultze-Motel from the University of Adelaide wrote a paper on heat-generating flowers, saying that these ancient plants co-evolved with beetles, which need a good deal of heat and energy to fly. So the pollinators are lured into the large flower, are rewarded with warmth for their own mating, then fly off to pollinate the next flower.


On day two, the pollen is being shed onto petals below.

 


 

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