From Black Panther@21:1/186 to All on Tue Dec 8 11:00:40 2020
EPOD - a service of USRA
The Earth Science Picture of the Day (EPOD) highlights the diverse processes and phenomena which shape our planet and our lives. EPOD will collect and archive photos, imagery, graphics, and artwork with short explanatory
captions and links exemplifying features within the Earth system. The
community is invited to contribute digital imagery, short captions and
Recently, my curiosity was triggered when I read about the ability of a
pinecone to open its woody scales in a dry environment and close
them again when the humidity in the air is high. Luckily, Yaar
HaMeginim (Defender's Forest) is only a 20-minute drive from my home
and is filled with Jerusalem pines. There were plenty of cones
(top) scattered about after a long dry summer so I gathered up several
dozen and took them home for an experiment. The open, dry cones were
dipped in water (bottom photo, left). After an hour, (bottom, right)
As the cones aren’t alive, this movement doesn’t use any internal
energy. The trick lies in the nature of the cone’s scales, which
consist of two different microscopic tissues that have different
affinities for water (they’re hygroscopic). This allows the cones
to close when atmospheric conditions become humid and to open up
when conditions are arid.
* Yaar HaMeginim Forest, Israel Coordinates: 31.85226, 34.94425
Hygroscopic Pinecones Mile-a-Minute Weed Great Beauty in
Dark Days Following the Sun Indian Pipe EPOD 20th - Diatom
* Discover Life
* Tree Encyclopedia
* What are Phytoplankton?
* Encyclopedia of Life - What is a Plant?
* USDA Plants Database
* University of Texas Native Plant Database
* Plants in Motion
* What Tree is It?
Earth Science Picture of the Day is a service of the Universities
Space Research Association.