Ca. 'Ghosts of the Forest' studied

The world's only white evergreens, the rare genetic mutants appear and disappear seasonally, the San Jose (Calif.) Mercury News reported.

Researchers at Stanford University and the University of California, Santa Cruz, are hoping to learn how such helpless trees can survive.

"It is a great puzzle," said Ghia Euskirchen, director of the DNA Sequencing Program at Stanford University School of Medicine.

Albinism is common in animals but it's very unusual in plants, because being green is central to a plant's existence since the plant pigment called chlorophyll is vital for photosynthesis. Without it, the trees have no way to manufacture the food needed for growth.

So the albino saplings of California can't live independently and remain sprouted on a parental trunk.

When conditions are bad, the parent tree withdraws all support and the seedlings perish, turning brown.

In times of abundant rain, they sprout again, flourishing.

"They come and go, like ghosts," Dave Kuty, docent at Cowell Park that has seven such trees, said. "They starve to death and shrink back. Then they reappear."

One redwood expert said it makes no sense.

"Almost everything that a redwood tree does is survival response," Cabrillo College historian Sandy Lydon, co-author of the book "Coastal Redwoods," said.

"The way they race for the sun. The way they regenerate. The way they respond if hit by lightning," he said. "Now here is something that has not a damn thing to do with any of that."

"I'm hoping that science can give us a clue," he said.

Copyright 2010 United Press International, Inc. (UPI).