This article speculated on the evolutionary origins of thermogenesis and observed how it predominates in ancient lineages of flowering plants like magnolias and water lilies. But thermogenesis goes back much farther than this, for it also occurs in cycads, nonflowering plants that arose in the Paleozoic. The male cones of some cycads, when mature, may maintain themselves at an astonishing 20 or more above the ambient temperature. This, as in the dead-horse arum, helps volatilize what is (to us) a foul smell. It is considered antisocial in Guam to have male cycads in one’s garden, but for certain insects, apparently, this smell is a delicious one, for they are attracted to the hot cones and help distribute their pollen.
New York, N.Y.