banner— Upper petal of a pealike flower. (See Fig. 6.1.)
basalt— A general term for a dark-colored igneous rock, commonly extrusive but locally as intrusive dikes (tubular igneous intrusions).
Basin and Range— Geomorphic province in eastern California and western Nevada; topography or landscape characterized by a series of tilted fault blocks.
biomass— The total mass or amount of living organisms in a particular area or volume.
biotite— Widely distributed rock-forming mineral of the mica group; layer-structure silicate containing essential potash, iron, magnesia, alumina, and H2 O in addition to silica; a typical formula is K(Mg, Fe+2 )3 (Al, Fe+3 )Si3 O10 (OH)2 .
bioturbated— Refers to sedimentary rocks that have been churned and stirred by organisms.
bipedal— Using two legs for locomotion.
boss— A swollen bump on the heads of certain toads.
bract— A reduced leaf subtending a flower, usually associated with an inflorescence.
breastwork— A small, curved rock wall, commonly used as a hunting blind.
buff— Medium to dark tan.
burred phrases— A trilled sequence of rough or gutteral sounds.
bursa— A small outpocketing or sac near the end of the digestive tube in a young bird.