elopment of the transport systems which could accommodate efficient water and carbohydrate transport, was ONE of the most important requirements for the evolution of an efficient land plant. Long-distance transport becomes a serious problem if inefficiencies exist in either system. Growing larger and taller would also not have been possible without the synthesis of lignin. Emergent land plants evolved over a very long time, with the first vascular land plants evolving during the Silurian about 440 MILLION years ago. The first conifers evolved during the Permian (290-250 my); flowering plants during the late Cretaceous (70-65 my) and the first angiosperms during the late Tertiary. The first vascular plants had FAIRLY primitive vascular systems - these were called protosteles fossil members of the Lycopodiales were at the height of their development and dominance during the Devonian and Carboniferous (408- 360 million years ago). The TWO examples that we have chosen to illustrate, have  primitive vascular systems (Lycopodium claviatum and L. saururus  illustrate examples of a fairly 'advanced' protostele, one in which the xylem and phloem has become dissected. We illustrate a fern (Rumohra) and then gymnosperms (Encephalartos, Araucaria,  a MEMBER of the pines). Common amongst these is their vessel-less xylem. We have included a few examples of angiosperms which have eustelic vascular systems in their primary stems,  (Cucurbit which has bicollateral vascular bundles, Nymphaea a hydrophyte with highly reduced xylem, and a Ligustrum species). Finally, we include Zea mays in which the atactostelic condition and dominant influence of the leaf vascular supply is most evident.