Soil plant atmosphere continuum Soil plant atmosphere continuum The soil-plant-atmosphere continuum (SPAC) is the pathway for water moving from soil through plants to the atmosphere. Continuum in the description highlights the continuous nature of water connection through the pathway. The low water potential of the atmosphere, and relatively higher (i.e. less negative) water potential inside leaves, leads to a diffusion gradient across the stomatal pores of leaves, drawing water out of the leaves as vapour. As water vapour transpires out of the leaf, further water molecules evaporate off the surface of mesophyll cells to replace the lost molecules since water in the air inside
Ornamental bulbous plant tubers tend to form at the sides of the parent plant and are most often located near the soil surface. A below ground stem tuber is normally a short-lived storage and regenerative organ developing from a shoot that branches off a mature plant. The new tubers are attached to a parent tuber or form at the end of an underground rhizome. In the autumn the plant dies except for the new offspring stem tubers, which in spring regrow one or more new shoots producing stems and leaves. Some plants also form smaller tubers and/or tubercules, which act like seeds, producing