Xanthophylls (Carotenoids): These are tetraterpenes with general formula C40H56O2. Xanthophylls are a class of oxygen-containing carotenoid pigments, responsible for the color of many of the yellow, orange, and red hues of flowers, fruits, vegetables (corn, pepper, etc.), egg yolks, and feathers, shells, or flesh of many animal species (flamingo, canary, shrimp, lobster, chicken, or salmonids). In plants, they are involved in photosynthesis with chlorophyll and are responsible for the red, yellow, and/or brown colors of autumn foliage as the chlorophyll levels decline.
Xeromorphy: Morphological characteristics, such as small, tough leaves, a heavy cuticle, etc., that are generally important for adaptation to dry environmental conditions.