Dawsonia (plant) lamella – chains of small cells on the upper surface of the leaves analogous to the mesophyll cells of vascular plant leaves. They increase the surface area of cell walls available for CO uptake, while at the same time maintaining layers of moist air between lamellae, reducing water loss. Lamella margins have a surface wax layer which prevents water from flooding into the interlamellar spaces. Dawsonia (plant) Dawsonia is a genus of acrocarpous mosses. "Dawsonia", along with other members of the order Polytrichales, are taller than most mosses and have thicker leaves. Their sporophytes have conducting systems analogous to those
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