lamina

noun

(L. lamina: thin piece [of metal, wood.]) The surface of a leaf excluding the petiole; the thin and usually flattened blade of a leaf, in which photosynthesis and transpiration occurs; the bulk of the lamina is made up of mesophyll cells interspersed by a network of veins (vascular bundles); the mesophyll is enclosed by a protective epidermis that produces a waxy cuticle. The leaflike part of the thallus of certain algae, notably kelps. In bryophytes, the flattened, generally unistratose and green part of the leaf blade excluding the costa and border; the expanded part of a thallus. A narrow, linear-elongate lobe of a foliose lichen, often arising from the primary lobes. See also stipe.