HOT STUFF
The term
thermogenesis
is derived from two Greek words:
thermos
(hot, or heat)
and
genesis
(origin, or creation). During thermogenesis, some living organisms
create the heat they need for survival. Humans, for example, shiver, forcing
their muscles to expend energy and create heat. In plants, thermogenesis has
different purposes. The dead horse arum generates heat to create the smell
that attracts pollinators. The skunk cabbage generates heat to warm up the
soil around it so that its seeds will sprout in the early spring.
The dwarf mistletoe is a parasitic plant that lives on the bark of lodgepole
pine trees in North America. As the mistletoe’s seeds mature, they heat
up. This heat causes the plant’s fruit to explode at speeds of 60 miles (97
kilometers) an hour, shooting seeds as far away as 30 feet (9 m). The flying
seeds are covered in a sticky substance that helps them adhere to lodgepole
pine needles. When rain falls, the seeds slide from a tree’s needles onto its
twigs, germinate, and set up root systems in the tree’s bark. A new dwarf
mistletoe then grows on the bark as a parasite of the tree. This system ensures
that the dwarf mistletoe species survives, although the plant eventually kills
the host trees. In the United States, the US Department of Agriculture is trying
to control the spread of dwarf mistletoe because of the damage it causes to
lodgepole pines.
Just because a plant smells disagreeable doesn’t mean the plant
is ugly or unappealing. In fact, some plants that smell disgusting
are quite attractive. If you were to stumble upon the white plume
grevillea (
Grevillea leucopteris
) in Australia, you might be distracted by
the beautiful yellow-white blooms of its f lowers. But don’t be fooled.
Get close and you’ll discover that this wily shrub’s f lowers smell
like dirty socks. In fact, the white plume grevillea’s nickname
is Old Socks. Maybe this plant would be more at home in your
school’s gymnasium.
Another smell-o-rific organism is one of the smallest. It is the
stinkhorn (family Phallaceae), which is common in tropical regions.
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P. U . , Yo u S t i n k !
