bio

Terrestrialization

The plant lineage's move from water into air, and the suite of inventions it required. The list is short and nothing on it is optional: a cuticle against water loss; a sporopollenin spore wall so reproduction could travel through dry air; stomata, because a watertight skin also cuts off the carbon supply; roots for anchorage and uptake; pigments to screen ultraviolet light; and finally lignified conducting cells, which solved suction and support together. On Earth the sequence ran over roughly seventy million years, from mid-Ordovician spores to the upright flora of the Rhynie Chert.