Leaf Yellow

Leaf

A leaf is a principal appendage of the stem of a vascular plant, usually borne laterally above ground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, flower, and fruit collectively form the shoot system. In most leaves, the primary photosynthetic tissue is the palisade mesophyll and is located on the upper side of the blade or lamina of the leaf, but in some species, including the mature foliage of Eucalyptus, palisade mesophyll is present on both sides and the leaves are said to be isobilateral. The leaf is an integral part of the stem system, and most leaves are flattened and have distinct upper (adaxial) and lower (abaxial) surfaces that differ in color, hairiness, the number of stomata, the amount and structure of epicuticular wax, and other features. Leaves are mostly green in color due to the presence of a compound called chlorophyll, which is essential for photosynthesis as it absorbs light energy from the Sun. A leaf with lighter-colored or white patches or edges is called a variegated leaf.

Yellow

Yellow is a color between green and orange on the spectrum of light. It is evoked by light with a dominant wavelength of roughly 575–585 nm. It is a primary color in subtractive color systems, used in painting or color printing. In the RGB color model, used to create colors on television and computer screens, yellow is a secondary color made by combining red and green at equal intensity. Carotenoids give the characteristic yellow color to autumn leaves, corn, canaries, daffodils, and lemons, as well as egg yolks, buttercups, and bananas. They absorb light energy and protect plants from photo damage in some cases. Sunlight has a slight yellowish hue when the Sun is near the horizon, due to atmospheric scattering of shorter wavelengths.

leaf

Noun

1. The usually green and flat organ that represents the most prominent feature of most vegetative plants.
2. A foliage leaf or any of the many and often considerably different structures it can specialise into.

Verb

1. To produce leaves; put forth foliage.
2. To divide (a vegetable) into separate leaves.

yellow

Noun

1. The color of sunflower petals and lemons; the color obtained by mixing green and red light, or by subtracting blue from white light; the color evoked by light of wavelength around 580 nm; one of the three primary colors in subtractive color systems.
2. The middle light in a set of three traffic lights, the lighting of which indicates that drivers should stop short of the intersection if it is safe to do so.

Adjective

1. Of a yellow hue.
2. Lacking courage.