page_title: Yellow
section_title: Trees
hierarchical_section_title: Yellow / Science and nature / Biology / Trees
caption_attribution_description: English: Aspen, Photographed by Doug Dolde along Snowbowl Road in Flagstaff, Arizona in October, 2009.
context_page_description: Yellow is the color between orange and green on the spectrum of visible light. It is evoked by light with a dominant wavelength of roughly 570–590 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 photodamage. Sunlight has a slight yellowish hue when the Sun is near the horizon, due to atmospheric scattering of shorter wavelengths.
  Because it was widely available, yellow ochre pigment was one of the first colors used in art; the Lascaux cave in France has a painting of a yellow horse 17,000 years old. Ochre and orpiment pigments were used to represent gold and skin color in Egyptian tombs, then in the murals in Roman villas.
context_section_description: Populus tremuloides is a deciduous tree native to cooler areas of North America, one of several species referred to by the common name aspen.  Populus tremuloides is the most widely distributed tree in North America, being found from Canada to central Mexico.
  The yellow birch (Betula alleghaniensis) is a birch species native to eastern North America, from Nova Scotia, New Brunswick, and southern Quebec west to Minnesota, and south in the Appalachian Mountains to northern Georgia. They are medium-sized deciduous trees and can reach about 20 m (66 ft) tall, trunks up to 80 cm (31 in) in diameter. The bark is smooth and yellow-bronze, and the wood is extensively used for flooring, cabinetry, and toothpicks.
  The thorny yellowwood is an Australian rainforest tree which has deep yellow wood.
  Yellow poplar is a common name for Liriodendron, the tuliptree. The common name is inaccurate as this genus is not related to poplars.
  The Handroanthus albus is a tree with yellow flowers native to the Cerrado of Brazil.
caption: American aspens, Populus tremuloides
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