Definition: A color hue with high wavelength of the long-wave end of the visible spectrum, evoked in the human observer by radiant energy with wavelengths of approximately 630 to 750 nanometers.
Definition: A color hue with high-medium wavelength that of that portion of the visible spectrum lying between red and yellow, evoked in the human observer by radiant energy with wavelengths of approximately 585 to 620 nanometers.
Definition: A color hue with medium wavelength of that portion of the visible spectrum lying between orange and green, evoked in the human observer by radiant energy with wavelengths of approximately 570 to 590 nanometers.
Definition: A spheroid quality inhering in a bearer by virtue of the bearer's resembling a ball (a sphere whose equatorial diameter is equal to the polar diameter).
Definition: A shallow stretch of a river or stream, where the current is above the average stream velocity and where the water forms small rippled waves as a result. It often consists of a rocky bed of gravels or other small stones.
Definition: Of plant duration, a plant whose life span extends over more than two growing seasons, c.f. annual, biennial, ephemeral, of flowering with respect to architecture, hapaxanthic, monocarpic, pleonanthic
Definition: Of plant duration, a plant whose life span extends over more than two growing seasons, c.f. annual, biennial, ephemeral, of flowering with respect to architecture, hapaxanthic, monocarpic, pleonanthic
Definition: A hard, thorny or needle-like structure which occurs on various organisms. Animals such as porcupines and sea urchins grow spines as a self-defense mechanism