aboriginal— Referring to the native inhabitants of any region.
accretion— Outbuilding of continental crust.
actinolite— A mineral, monoclinic amphibole similar to the mineral tremolite but iron-bearing; a typical formula is Ca2 (MgFe)5 Si8 O22 (OH2 ).
acuminate— Tapering to the apex, the sides more or less pinched in before reaching the tip. Compare acute .
acute— Tapering to the apex, with the sides straight or nearly so; usually less tapering than acuminate.
adiabatic— An atmospheric process in which descending air is compressed and warmed and ascending air expands and is cooled.
aeolian— Pertaining to the wind; especially said of such deposits as loess (windblown dust of Pleistocene age) and dune sand, of sedimentary structures such as windformed ripple marks, or of erosion and deposition accomplished by the wind.
aggregation— The collection of units or parts into a mass or whole.
akene— A small, dry, hard, one-seeded fruit that remains closed at maturity.
albite— Triclinic mineral of feldspar group, NaAlSi3 O8 , a variety of the mineral plagioclase.
alkali dust— Fine particles (salts) in desert soils that are concentrated on dry lake beds.
alkaline— Pertaining to substances with a pH greater than 7; basic.
allopatric— Occurring in different geographic regions.
alluvial deposits— Poorly consolidated sand, gravel, silt, and clay.
alluvial fan— An outspread, gently sloping mass of alluvium deposited by a stream, especially in an arid or semiarid region where a stream issues from a narrow canyon onto a plain or valley floor. Viewed from above, it has the shape of an open fan, with the apex at the valley mouth.
alluvial soil— A soil formed from materials deposited by moving water, as along a river bed.
alluvium— A general term for clay, silt, sand, gravel, or similar unconsolidated detrital material deposited by running water.
Alpine Fell-fields— The plant community at elevations above treeline, composed of cushion plants and other low perennials interspersed between large rock surfaces and presenting little exposure to the elements.
Alpine Steppe— Arid plant community above treeline.
alpine Tundra— See Alpine Fell-fields .
altocumulus— A principal cloud type that appears in many forms but is always considered a cloud of median height above the terrain, as opposed to a low (cumulus or stratus) or high (cirrus) cloud.
Amphisbaenia— An order of limbless, burrowing reptiles.
anaerobic— Lacking available free oxygen for processes such as respiration and metabolism.
anal fin— The median ventral fin located just posterior to the anus.
andalusite— Varicolored orthorhombic mineral (i.e., crystal system with three axes of symmetry that are mutually perpendicular), Al2 SiO5 . Metamorphic mineral formed at medium pressures and temperatures.
annealing— Recrystallization involving grain coarsening due to the long-term attendance of relatively high metamorphic temperatures.
anomaly— A deviation from the normal value for the same region (usually) in temperature or precipitation over a specified period.
antenna— Flexible appendage on head of arthropods, used for touching and smelling.
anther— The pollen-bearing part of the stamen. (See Fig. 6.1).
anthesis— The action or period of opening of a flower.
anticline, anticlinal— A fold, generally convex upward, whose core contains stratigraphically older rocks.
anticlinorium— A composite anticlinal structure of trough- and arch-shaped folds.
anticyclone— A large-scale atmospheric circulation in which the airflow is clockwise as viewed from above — the opposite direction to that of a cyclone.
apposite— Proceeding from opposite sides of a stem, as opposite leaves. (See Fig. 6.1).
appressed— Pressed flat against another organ or surface.
arachnid— A member of the Class Arachnida, characterized by the presence of one pair of preoral appendages with two or three joints (e.g., spiders, scorpions, mites, and ticks).
arc— Islands or mountains arranged in a great curve.
archaeology— The study of human lifeways by means of material remains.
arête— A rocky, sharp-edged ridge or spur, commonly present above the snowline in rugged mountains sculptured by glaciers, and resulting from the continued backward growth of the walls of adjoining cirques.
arthropods— Segmented invertebrates having jointed legs, such as insects and spiders.
artifact— Portable object modified by human agency.
assemblage— Relatively homogeneous group of fossils that recur at the same stratigraphic level.
atlatl— Spear thrower; an implement used to propel an arrowlike projectile or "dart."
attenuation— A reduction in the amplitude of a signal, seismic wave, or rock fold.
auditory— Pertaining to hearing.
aureole— A zone surrounding an igneous intrusion in which the country rock shows the effects of contact metamorphism.
avifauna— The species of breeding birds that inhabit a region; all species of birds generally present in a region at any season.
awl— A sharp, pointed bone or wood tool used in basket making.
axil— Upper angle formed by a leaf branch with the stem. (See Fig. 6.1.)
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.
caecilian— An order of limbless, burrowing amphibians occurring in the New and Old World tropics.
calcareous— Refers to limestone or soil impregnated with calcium.
calcic— Said of minerals and igneous rocks containing a high proportion of calcium.
caldera— A large, basin-shaped depression at the site of a volcano (e.g., Crater Lake, Oregon).
callosity, callosites— A hardened thickening.
calyx— The external, usually green, whorl of a flower, contrasted with the inner, showy corolla.
canescent— Covered with grayish-white or hoary fine hairs.
cap cloud— An apparently stationary cloud enveloping a peak or mountain range. It is formed by the cooling and condensation of humid air forced up the windward side of the mountain.
Carbon-14,14C— A heavy radioactive isotope of carbon produced in nature by the reaction of atmospheric nitrogen with cosmic rays. Incorporated into green plants with photosynthesis as C14 O2 , it decays at an approximately known rate, known as its half-life (which is 5,568 years) when the system is closed (i.e., the plant dies), allowing organic material to be dated.
carbonate— A mineral rich in CO3 -2 or sediment formed by the organic or inorganic precipitation of carbonate-rich compounds (e.g., limestone, dolomite).
carpel— One of the foliar units of a compound pistil or ovary; a simple pistil has one carpel. A foliar, usually ovule-bearing unit of a simple ovary.
carpellate— Pertaining to a flower with one or more carpels but no functional stamens; possessing or composed of carpels.
catkins— Hanging clusters of tiny flowers or bracts of willows, alders, and other plants.
centipede— Member of the Class Chilopoda. Centipedes usually have one pair of legs on each body segment.
cephalothorax— The part of the arachnid body that includes the head and the legs.
cereus(pl. cerci)— Appendage located on the anal segment ("tail") of cockroaches and other insects.
Cheatgrass— Annual grass of the Genus Bromus .
chlorite— A layer-structure silicate mineral consisting of essential amounts of alumina, magnesia, iron, and H2 O, in addition to silica; its formula is approximately (MgFe+2 )5 Al2 Si3 O10 (OH)8 .
cinder cone— A conical hill formed by the accumulation of volcanic cinders.
cirque— A deep, steep-walled recess or hollow, horseshoe-shaped or semicircular in plan view, situated high on the sides of a mountain and produced by the erosive activity of a mountain glacier.
citrus— A principal type of cloud composed of ice crystals; usually the highest form of cloud observed.
clones— A population of cells or individuals derived by asexual division from a single cell or individual. (See also vegetative reproduction .)
cloud fall— The extension of the cap cloud down the leeward slope of a mountain range to the level where warming of the air causes the cloud particles to evaporate.
coalesced family groups— Several joined families.
col— A high, sharp-edged pass or saddle-like depression in a mountain range, especially one formed by the headward erosion of two cirque glaciers.
coleopteran— A member of the Order Coleoptera, beetles.
colluvial— Pertaining to loose and incoherent deposits, usually at the foot of a slope or cliff, brought there chiefly by gravity; clasts commonly angular in shape, with deposit poorly sorted.
compound eye— An eye composed of hundreds to thousands of tiny individual "eyes," occurring on insects and some other arthropods.
compound-fletched arrow— An arrow consisting of multiple, fitted segments to which feather vanes are affixed to promote stability in flight.
cone— The dry, compound fruit of pine, spruce, and other trees, consisting of overlapping scales (same as strobilus).
congener— A species in the same genus; closely related species.
conglomerate— A coarse-grained sedimentary rock composed of rounded to subangular fragments or rounded clasts.
conifer— A cone-bearing tree.
cordate— Of a conventional heart shape, the point apical.
cordierite— A blue orthorhombic (see andalusite ) mineral, (Mg1 = e+2 )2 Al4 Si5 , commonly a low-pressure metamorphic mineral.
corm— A short, solid, bulblike underground stem, such as the "bulb" of Gladiolus.
cornice— An overhanging mass of snow above a steep leeward mountain slope.
corolla— The inner whorl of a flower, composed of colored petals that may be almost wholly united.
corymbose— Descriptive of a flat-topped flower cluster (corymb).
cotyledon— The primary leaf or leaves of a plant embryo.
covey— A flock or group, as applied to quail.
coxa— The leg segment closest to the body (See Fig. 7.3).
crenate— Toothed, with teeth rounded at apex.
Creosote Bush Scrub— Low-elevation Mojave Desert vegetation type, with Creosote Bush (Larrea tridentata ) as the dominant species.
crustacean— A member of the Class Crustacea; any arthropod belonging to the Superclass Crustacea, characterized by the presence of two pairs of antennae on the head.
crustal compression/extension— Outermost layer or shell of the earth undergoing compression or extension.
cryoplanation surface— A relatively flat surface reduced by processes associated with intensive frost action supplemented by the actions of running water, moving ice, and other agents.
culm— The specialized stem of grasses, sedges, and rushes.
cumuliform— Like cumulus clouds, that is, dome- or tower-shaped as opposed to horizontal (stratiform).
cumulonimbus— Cumulus cloud commonly spread out in the shape of an anvil.
cuneate— Wedge-shaped; rather narrowly triangular, the acute angle downward.
cyclone— A large-scale atmospheric circulation in which the airflow is counterclockwise as viewed from above.
cyme— A flat-topped or convex paniculate flower cluster with central flowers opening first.
deadfall— A trap in which the prey (usually small) is killed by a falling stone or log.
debris flow— A moving mass of rock fragments, soil, and water, more than half of the particles larger than sand size, often the result of an intense thunderstorm and accompanying flash-flooding.
deciduous— Falling off at a certain season or stage of growth (e.g., plants with deciduous leaves as opposed to evergreens).
decoy— To attract by means of imitated sounds or models.
decurved— Curved downward or bent down.
defile— Narrow natural passages often favored as hunting locations.
deflexed— Turned abruptly downward (same as reflexed). (See Fig. 6.1.)
deltoid— Triangular leaf, attached at the center of one side.
demographics— Phenomena related to populations.
dendrochronologists— Scientists who study the record of information provided by trees and other woody plants in their ring structure or series.
dendrochronology— A dating method in which distinctive sequences of tree-ring widths are used to establish age.
dentate— Toothed, with the teeth directed outward; loosely used for any large teeth.
diapause— A period, usually longer than one month, in the life cycle of an organism during which the organism is quiescent.
dihedral— Having wings set off from the body at a distinct angle from the horizontal.
dimorphism— The existence of two size or color categories within a species, especially as occurs between the sexes.
dioecious— Flowers unisexual, having the male and female (or staminate and ovulate) elements on different individuals.
diopside— A mineral of the clinopyroxene group, CaMg(SiO3 )2 . Occurs as a mineral in contact metamorphism.
dipteran— A member of the Order Diptera, a two-winged fly.
discordant— Lack of parallelism between adjacent strata.
disjunct— Discontinuous, widely separated.
diurnal— Active during the day.
dolomite— 1. A common rock-forming mineral, CaMg(CO3 )2 . Part of the magnesium may be replaced by ferrous iron. Dolomite is white to light-colored and has perfect rhombohedral cleavage. 2. A sedimentary rock commonly interbedded with limestone.
dolomite barrens— Areas of dolomite that from a distance appear devoid of vegetation.
dorsal— Refers to the "back" or upper side of an organism.
duff— Organic material (predominantly needles and leaves) that accumulates beneath trees.
echolocation— A system bats use to locate flying prey by monitoring the patterns of high-frequency sound waves emitted by the bat.
ecofacts— Natural materials (e.g., stones, bones, seeds) used or transported but not physically modified by humans.
ecosystem— The system of ecological relationships on which a particular organism or group of organisms depends for existence. It may include such factors as weather, water, food, and predators.
edaphic— Pertaining to ecologic formations or effects resulting from or influenced by local conditions of the soil or substrate.
ejecta (volcanic tuff)— Material thrown out from a volcano.
elytra— Hardened forewings of a beetle, covering the membranous hindwings.
emplacement— A term used to refer to the process of intrusion (e.g., emplacement of granitic rocks).
en echelon— In apparent formation or in rows oriented in about the same direction.
endangered— As defined in the Endangered Species Act of 1973, refers to any species or subspecies in danger of extinction throughout all or a significant portion of its range.
endemic— Restricted to a locality or region.
epidote— A green mineral, Ca2 (Al, Fe+3 )3 Si3 O12 (OH). Occurs in low-grade metamorphic rocks.
epiphenomena— A superficial or secondary phenomenon accompanying another and caused by it.
equitant— Two-ranked leaves, flattened, with edges toward and away from the axis; astride, as the leaves of an Iris ; overlapping or "horseback" leaves.
erratic— A rock fragment transported by a glacier and deposited at some distance from where it was derived; generally, resting on bedrock of different lithology.
escarpment— A long, more or less continuous cliff or relatively steep slope produced by erosion or faulting.
ethnographic— Pertaining to aboriginal lifeways observed firsthand rather than reconstructed through archaeology.
exserted— Protruding, as stamens projecting beyond the corolla; not included, i.e., not protruded. (See Fig. 6.1.)
fanglomerates— Sedimentary rocks of heterogeneous materials that were originally deposited in an alluvial fan and have since become cemented (by carbonates or silica) into solid rock.
farinose— Covered with a meal-like powder.
fascicle— A bundle of pine leaves or other needle-like leaves of gymnosperms.
fault— A fracture or a zone of fractures along which there has been displacement of the sides relative to one another.
fauna— An entire animal population.
feature— A group of objects whose positioning relative to each other is due to human activity.
fell-field— Habitats above treeline supporting only low-growing, commonly sparse vegetation.
felsenmeer— An expanse of large blocks of rock produced by block separation along joints and shattering by frost action at high altitudes.
femur— A segment of an arthropod leg between the coxa and the tibia. (See Fig. 7.3.)
filiform— Threadlike; long, slender, and tapering at both ends.
flexuous— Gently zigzagging.
fluorite— A transparent to translucent varicolored mineral, CaF2 .
fluvial— Of or pertaining to rivers; produced by the action of a stream or river.
foehn— A warm, dry wind blowing down the side of a mountain.
foehn wall— The steep leeward boundary of clouds over a mountain range during foehn conditions; generally, the cap cloud and cloud fall considered together.
foliaceous— Leaflike, said especially of sepals or bracts that resemble leaves in texture or appearance.
forb— An herb or annual flowering plant, other than grass (e.g., small broad-leaved plants).
formation— A body of rock that is mappable and is continuous over a region.
galea— The helmetlike upper lip in certain two-lipped corollas, such as Castilleja sp. (Indian Paintbrush). (See Fig. 6.1.)
garnet— A complex group of minerals (e.g., almandine, andradite, grossular, pyrope) commonly present in metamorphic rocks.
garrulous— Noisy and active behavior that characterizes flocks of some birds.
gelifluction lobe— A tonguelike mass of debris, usually associated with periglacial conditions, where soil saturation occurs because frozen ground prevents the downward percolation of water. The melting of ice and snow saturates the surface zone, and soil flowage results.
geologic time scale— An arbitrary or relative chronologic arrangement of geologic events, commonly presented in chart form with the oldest event and time unit at the bottom and the youngest at the top.
geosyncline— A mobile downwarping of the crust of Earth.
glabrous— No hairs present at all; also used for smooth .
glacial till— Dominantly unsorted and unstratified drift, deposited directly by and underneath a glacier without reworking by meltwater.
glandular— Secreting sticky fluid; bearing glands, commonly on hairs.
glandular-hairy— A surface bearing both glands and hairs, the hairs commonly tipped with glandular secretion.
glaucous— Covered with a whitish or bluish waxy covering; loosely applied to any whitish surface.
gleaning— Picking from the surface of a plant or object.
glochids— A barbed hair or bristle, such as the minute bristles of Beavertail Cactus (Opuntia sp.).
glomerules— A dense cluster of flowers, usually small.
gonad cycle— The annual cycle of activity and inactivity of bird reproduction.
granite— 1. A plutonic or deep-seated rock in which quartz makes up 10 to 50% of the felsic (igneous rock having abundant light-colored minerals in its mode) components, and the alkali feldspar/total feldspar ratio is 65 to 90%. 2. Broadly applied, any holocrystalline quartz-bearing plutonic rock.
granitic soils/substrate— Soil derived from granitic rocks.
granodiorite— A group of coarse-grained plutonic rocks intermediate in composition between quartz diorite and quartz monzonite, containing quartz, oligocase or an-
desine, and potassium feldspar, with biotite and hornblende. It is the approximate equivalent of the intrusive rock rhyodacite.
graupel— Snow pellets, a form of frozen precipitation.
greenschist facies— A set of physical conditions attending the production of metamorphic rocks rich in the minerals albite, epidote, chlorite, and tremolite-actinolite (and rarely biotite).
grubs— Soft, thick, wormlike larvae of certain insects.
hafted— An object such as a stone knife blade that has been affixed to a handle to make it more serviceable.
halteres— Modified hindwings of a dipteran, used as balance organs during flight.
hemipteran— Member of the Order Hemiptera, true bugs that have mouthparts adapted for piercing and sucking and usually two pairs of wings during life cycle.
herb— A plant with no persistent woody stem aboveground.
herbaceous— Pertaining to an herb, opposed to woody; having the texture or color of a leaf; dying to the ground each year.
herpetologist— A person who studies amphibians and reptiles.
homopteran— Member of the Order or Suborder Homoptera, insects with sucking mouthparts (e.g., aphids).
horn sheath— Outer horn material, analagous in composition and origin to fingernail, that grows over a horn core made of bone. In contrast, an antler is entirely bone.
hybridize— To interbreed or cross two different races.
hymenopteran, hymenopteron— Member of the Order Hymenoptera, highly specialized insects with complete metamorphosis, including bees and ants.
hypersaline— High in salt content.
igneous— Said of a rock or mineral solidified from molten or partly molten material (a magma).
incisor— One of a set of cutting-adapted teeth at the front of the jaw.
inflected— Refers to songs or calls of birds characterized by a change in pitch or loudness.
inflected slurs— Bird calls or songs that smoothly change in pitch.
inflorescence— The disposition of flowers on an axis; the flower arrangement on a plant. (See Fig. 6.1.)
inselberg— An isolated residual knob or hill rising abruptly from a lowland erosion surface, especially in desert regions. It is characteristic of a late stage of the erosion cycle.
instar— The stage between moults of a larval or nymphal insect.
interfluve— The relatively undissected upland or ridge between adjacent streams flowing in the same general direction.
internasal scales— Scales between the nostrils.
internode— The portion of a stem between nodes. (See Fig. 6.1.)
introduced— Refers to a plant or animal brought in deliberately by man and growing in the area without cultivation. For example, an introduced fish may be "exotic" (from a foreign land) or "transplanted" (outside its native range but still within the country of origin).
intrusive— Pertaining to an intrusion (emplacement of magma in preexisting rock).
involucre— A whorl of bracts subtending a flower cluster, as in the heads of sunflowers. (See Fig. 6.1.)
isotope— One or more species of the same chemical element that vary in the number of neutrons in the nucleus.
keeled— Possessing a prominent ridge; also refers to the two lower and united petals of a pealike flower. (See Fig. 6.1.) In reptiles, refers to scales with a raised line down the middle.
lamina— The blade or expanded part of a petal or leaf.
lance-elliptic— Descriptive of a leaf shape that falls between lance-shaped and elliptic.
lanceolate— Lance-shaped; several times longer than wide, broadest toward the base and tapering to the apex.
languid— A leisurely or relaxed pace.
lapilli— Pyroclastic rock (volcanic ejecta) in the general size range of 2 to 64 mm.
lapse rate— The decrease of air temperature with height.
larva(e)— A juvenile insect; usually does not look like the adult.
legume— The fruit of a pealike flower; members of the Family or Superfamily Leguminosae.
leks— Tightly clumped assemblies of courting males to which females are attracted for mating.
lepidopteran— A member of the Order Lepidoptera, comprising the butterflies and moths, which possess wings covered with scales.
ligule— Strap-shaped or tongue-shaped; the straight-sided part of a flower ("petal") in the Chicory Tribe of the Aster (Sunflower) Family.
limestone— Rock composed chiefly of calcium carbonate; soils derived from those rocks.
lithospheric plate— A layer of the Earth that includes the crust and part of the upper mantle, approximately 100 km thick.
loam— An easily crumbled mixture of clay, silt, and sand; said of soil; usually favorable for plant growth.
macrofossils— A fossil large enough to be studied without the aid of a microscope or hand lens.
maggotlike— Refers to a wormlike larva with no legs or visible jaws.
magma— Naturally occurring hot mobile rock material, generated within the Earth.
magmatic stoping— Magmatic emplacement on intrusion that involves detaching and engulfing pieces of the country rock.
magnetite— A black, strongly magnetic, opaque mineral of the spinel group, (Fe, Mg)Fe2 O4 .
mandibles— The jaws of an insect.
mano— Small, hand-held stone used in seed grinding.
maxilla— An appendage on the insect head used for manipulating food, located behind the mandibles.
meloid— A member of the Family Meloidae, comprising beetles variable in form, head turned down, with leathery wing covers (e.g., Blister Beetle).
mesa— A plateau or tableland with steep sides.
mesic— Refers to an environment with an average or adequate supply of moisture for plant growth.
mesophyll— The ground tissue of a leaf, located between the layers of epidermis; mesophyll cells generally contain chloroplasts (plastids that contain chlorophyll).
mesoscale— Having to do with airflow patterns and atmospheric features with dimensions in the range of 1 to 100 mi or 1 to 150 km.
metabolic rate— The rate at which an animal oxidizes chemical products of food digestion and stored fats to produce energy.
metamorphism— A mineralogical, chemical, and structural adjustment of solid rocks to physical and chemical conditions imposed at depth.
metate— Flat or basin-shaped stone that serves as a platform in seed grinding.
metavolcanic— Volcanic rocks that show evidence of having been subjected to metamorphism.
mica— A complex group of phyllosilicate minerals, characterized by low hardness, and readily split into their plastic laminae.
microcline— A varicolored mineral of the alkali feldspar group, KAISi3 O8 , common in igneous rocks.
middens— Any organic debris deposited by an animal.
midrib— The central rib of a leaf. (See Fig. 6.1.)
millibar— Abbreviated mb, a unit used in reporting atmospheric pressure. For example, average sea-level pressure is 1,013.2 mb, 700 mb is near 10,000 ft, and 500 mb is usually between 18,000 and 19,000 ft.
millipede— A member of the Class Diplopoda, with cylindrical, segmented body, and two pairs of legs on most segments.
molt— The orderly replacement of feathers, hair, or scales.
monadnock— A hill rising conspicuously above the general level of the landscape, representing an isolated erosional remnant in an area that has been largely beveled to a flat plain or plateau.
monocot plant— Plant with parallel-veined leaves (e.g., lily, Iris ).
monoecious— Having staminate and pistillate flowers on the same plant but not both in the same flower.
monsoon— A seasonal wind generally blowing from ocean to land in summer and in the opposite direction in winter.
montane— Pertaining to mountains.
moraine— A mound or ridge of unstratified glacial drift, chiefly glacial till, deposited by the direct action of glacier ice.
moult— The process in which an arthropod sheds its old skin and hardens the new one underneath.
natal— Pertaining to an animal's birth.
nectary— An organ that secretes or contains nectar.
nocturnal— Active at night.
normal fault— A fault in which the hanging wall (rocks above the fault plane) have moved downward relative to the footwall (rocks below the fault plane).
numu— Word meaning "the people," used by Numic speakers referring to themselves as a group.
nunatak— An isolated knob or peak of bedrock that projects prominently above the surface of a glacier and is surrounded by glacier ice; sculpted by periglacial processes.
nymph— A juvenile insect, usually somewhat resembling the adult of the species.
nymphalid— A member of the Family Nymphalidae, medium-sized butterflies (e.g., Monarch Butterfly, Mourning Cloak, Buckeye, Red Admiral).
oblanceolate— Inversely lanceolate.
obovate— Reverse of ovate, the terminal half broader. (See Fig. 6.1.)
obsidian— A naturally occurring glass of volcanic origin.
obsidian hydration— Dating method in which the thickness of a microscopic "hydration" layer is used to determine the age of a piece of obsidian.
opportunistic— Taking advantage of what is available.
order of magnitude— Refers to a hierarchy of relative size, with each class about 10 times the size of the next smaller class. Features that have characteristic dimensions such as 10, 100, 1,000 and 10,000 mi are said to be of different orders of magnitude.
orogeny— Process of formation of mountains.
orographic— Pertaining to or caused by mountains.
orthopteran— A member of the Order Orthoptera, insects with biting mouthparts, two pairs of wings or none (e.g., crickets and grasshoppers).
ovary— The part of the pistil that contains the ovules. (See Fig. 6.1.)
ovate— The shape of an outline of a hen's egg, the broader end downward.
ovipositor— A pointed organ located on the anal segment ("tail") of an arthropod, used for laying eggs.
ovoid— Solid ovate or solid oval.
oxidation— A biochemical reaction in which a molecule loses an electron, commonly through addition of an oxygen atom, and during which energy is released.
Paiute— A term loosely applied to certain native Numic-speaking peoples. Also spelled Piute. The native Owens Valley peoples are more properly called Mono.
palmate— Describes a leaf with lobes or divisions attached or running down toward one place at the base.
palp— Short appendage located on the head and mouthparts of an arthropod.
panicle— A compound racemose inflorescence.
pappus— A crown of bristles (hairlike) or scales on the summit of the akene in the Aster (Sunflower) Family. Some forms have only a shallow crown. (See Fig. 6.1.)
parching— A step in seed preparation in which seeds are made more edible and susceptible to grinding by heating them with live embers.
parotid gland— Large, swollen glandular area lying behind the head.
parthenogenic— Bearing young from unfertilized eggs.
passerines— Species of the Order Passeriformes, the perching birds (e.g., pigeons).
pedicel— The stalk of a single flower.
peduncle— The stalk of a flower or cluster of flowers.
peirid— A member of the Family Pieridae, butterflies, mostly medium-sized (e.g., Cabbage Butterfly, Dogface, "sulphurs").
pelage— Fur coat.
perched alluvial fan— See alluvial fan; section of fan, usually uplifted above surface of contemporary stream.
perennial— Lasting from year to year.
perianth— The petals and sepals taken together. Used particularly when the outer and inner portions of the floral envelope cannot be distinguished.
periglacial— 1. Said of the processes, conditions, areas, climate, and topographic features at the immediate margins of glacier ice sheets and influenced by the cold temperature of the ice. 2. By extension, said of an environment in which frost action is an important factor or of phenomena induced by a periglacial climate beyond the periphery of the ice.
petiole— A leaf stalk. (See Fig. 6.1.)
phyllaries— Individual bracts of the involucre of a flower head in the Aster Family. (See Fig. 6.1.)
physiognomy— The physical structure of the plant community; growth forms of plants composing the vegetation.
pinnate— Describes a compound leaf having leaflets arranged on each side of a common petiole or leaf stalk.
Pinyon Woodland— Lower-elevation montane plant community dominated by an overstory of Pinyon Pine (Pinus monophylla ).
Pinyon-juniper Woodland— A mid-elevation desert habitat.
pistil— The ovule-bearing organ of a flower, consisting of a stigma, style (elongated part of pistil), and ovary.
pistillate— Provided with pistils and without stamens; female.
plagioclase— A complex mineral group, (Na, Ca)Al(Si, Al)SiO2 , including the rock-forming minerals albite, oligoclase, andesine, labradorite, and anorthite.
planation surface— A fundamentally flat or level surface created by processes of erosion.
planted— A general term used to describe the introduction of fish into a body of water, usually from a fish hatchery.
plate rifting— The process in which two of the Earth's plates spread apart and new crust is created between them.
Pleistocene— An epoch of the Quaternary Period, following the Pliocene Epoch of the Tertiary Period and before the Holocene. It began about 1.7 million years ago and lasted until the start of the Holocene, some 10,000 years ago.
plumose antennae— Featherlike antennae.
polygamous— Bearing unisexual and bisexual flowers on the same plant.
polyploidy— An animal possessing more than two sets of chromosomes.
Precambrian— Geologic time and time-rock term, before the beginning of the Paleozoic Era (ca. 570 million years ago); includes about 90% of geologic time.
proleg— A leglike appendage on an insect larva, not jointed like a true arthropod leg.
pro-talus rampart— An arcuate ridge of angular rocks originating from a cliff or steep rocky slope above and marking the downslope edge of an existing or melted snowbank. The rocks accumulate at the edge of the snowbank, some distance beyond any talus near the base of the cliff.
puberulent— Minutely pubescent.
pubescent— Covered with soft hairs; downy.
pumice— A light-colored, glassy rock.
quadrant— The area within a 90° arc; for example, the southwest quadrant encompasses the area between south and west.
quadrupedal— Using four legs for locomotion.
quartzite— A metamorphic rock consisting mainly of quartz, formed by recrystallization of sandstone by regional or thermal metamorphism; a metaquartzite or metamorphosed quartzite is referred to as an orthoquartzite.
Quaternary— Period of the Cenozoic Era of relative geologic time, following the Tertiary Period; also, the corresponding system of rocks. It began 1.7 million years ago and extends to the present. It consists of two epochs: the Pleistocene and the Holocene, or Recent.
raceme— A simple, elongated inflorescence with each flower about equally pedicelled. (See Fig. 6.1.)
racemose— Of the nature of a raceme or in racemes.
rachis— The axil of a spike or raceme or of a compound leaf. (See Fig. 6.1.)
radiocarbon— See carbon-14 .
radiometric dating— Calculating an age in years for geologic materials by measuring the presence of a short-life radioactive element (e.g., carbon-14 or potassium/argon-40).
raptor— A bird of prey, such as an eagle, hawk, falcon, or owl.
rawinsonde— A device attached to a helium-filled balloon that, as it ascends, relays radio signals of atmospheric pressure, temperature, and humidity readings while it is being tracked by radar to determine wind velocity at various levels.
reflexed— Abruptly bent downward; deflexed. (See Fig. 6.1.)
regenerated tail— A broken tail that has regrown.
regime— A predominant or characteristic spatial or temporal (seasonal) pattern, as in rainfall.
regolith— A general term for the layer of unconsolidated rock material or debris that forms the surface of the land and overlies bedrock.
relict— An individual or group remaining on the site of a once-larger population; may pertain to plants or animals, or even soils and other geologic features.
resinous— Containing resin or having the shining appearance of being resin-coated.
resonance— The phenomenon of amplification of an atmospheric wave by a forced wave imposed by a boundary condition such as the shape of the terrain profile in the form of parallel mountain ranges.
reticulate— A color pattern consisting of linear markings resembling the meshes of a net.
reverse fault— An inclined fault in which the rocks above the hanging wall (above the fault plane) have moved up relative to those below the foot wall (below the fault plane).
rhizome— An underground stem or rootstock that roots as it progresses, commonly described as running rootstock; a type of rootstock with scales at the nodes that become leafy shoots above.
ridge— An anticyclonic (clockwise) bend in the horizontal airflow pattern in the synoptic (weather map) scale.
rime icing— An opaque formation of ice formed by the rapid freezing of supercooled water drops as they impinge upon a solid object.
riparian— Descriptive of plants located on watercourses or along bodies of water.
roche moutonée— A glacially sculpted knob of bedrock with its long axis oriented in the direction of ice movement; the upstream side is gently inclined, rounded, and striated, with the downstream side steeper and fragmented by plucking. Mountains shaped like sheep (French).
roll cloud— The turbulent cumuliform cloud in the crest of a lee wave; generally forms near or somewhat above mountaintop level.
root crown— An enlarged, commonly woody structure formed at the junction of the root and the stem.
rostral scale— The scale at the tip of the snout.
runway— Pathway used repeatedly by some small rodents.
saline— Salty; pertaining to soil or water rich in soluble salts.
salverform— A corolla with a slender tube abruptly expanding into a flat border, as in phlox. (See Fig. 6.1.)
samara— Simple, dry, one-seeded or two-seeded winged fruit.
sandstone— A cemented or otherwise compacted sedimentary rock, commonly composed of quartz grains of sand size (0.6–2 mm).
sapsucker borings— Sap-producing holes drilled in trees by woodpeckers of the Genus Sphyrapicus .
scapolite— A complex group of aluminum-silicate minerals, commonly in calcium-rich metamorphic rocks.
scorpioid— A one-sided inflorescence gently coiled at the end like the tail of a scorpion. (See Fig. 6.1.)
scurfy— Clothed with small, branlike scales.
sedentary— Tending to stay quietly in one place.
sedges— A group of plants resembling grasses; solid stems; grasses with hollow stems.
sedimentary— Pertaining to or containing sediment (e.g., sedimentary rock).
seleniferous soil— Soil containing the element selenium.
semiserotinous— Refers to cones that open slowly, releasing seeds over a prolonged time period. Seed shed may be induced by fire.
sepal— A segment of the calyx; the outer whorl of a flower. (See Fig. 6.1.)
sequence— A succession of geologic events, processes, or rocks arranged in chronologic order to show their relative positions.
serrulate— Serrate with small teeth.
serviceberry— Tree or shrub of the Genus Amelanchier (Family Rosaceae).
sessile— Attached directly at the base, not stalked, as a leaf without a petiole.
setpoint— A point (e.g., temperature) at which a feedback system attempts to maintain itself, such as the temperature setting on a home heating system.
settlement category— Class of settlement used by aboriginal peoples. Base camps and Pinyon camps are two of many categories of settlement used by the aboriginal peoples of eastern California.
settlement system— An organized pattern of aboriginal land use that incorporates one or more settlement categories.
shadscale— Common name for Atriplex confertifolia, a common desert shrub in the Chenopodiaceae.
Shadscale Zone— Semidesert community grown to saltbush or shadscale (Genus Atriplex ).
shale— A fine-grained, detrital, sedimentary rock formed by the compaction of clay, silt, or mud. It is finely laminated and splits readily. Shale is well indurated but not as hard as argillite or slate. It may be red, brown, black, or gray.
silicle— A short silique, not much longer than wide.
silique— A narrow, many-seeded capsule, much longer than wide, usually in the Mustard Family.
sillimanite— An orthorhombic (see andalusite ) mineral, Al2 SiO5 ; forms at the highest temperatures and pressures of a regionally metamorphosed sequence.
siltstone— Sedimentary rock composed of silt, having the texture of shale but lacking fine laminations.
site— Literally, any place used by humans for activity as reflected by the presence of artifacts and features (see artifact, feature ).
slate— A compact, fine-grained metamorphic rock that can be split into slabs.
solifluction— The slow downslope movement of waterlogged soil; includes the flow occurring at high elevations in regions underlain by frozen ground acting as a downward barrier to water percolation; initiated by frost action and augmented by meltwater resulting from alternate freezing and thawing of snow and ground ice. (See also gelifluction lobe .)
spathelike— Having the appearance of a broad, sheathing bract, as in the Calla Lily.
spatulate— Spatula-shaped; rounded above and gradually narrowing to the base, broader in the upper half. (See Fig. 6.1.)
spinescent— More or less spiny.
spur— A slender projection from a petal or sepal.
squamate— Covered with scales.
stamen— The part of the flower producing the pollen, composed (usually) of anther and filament.
staminate— Having stamens but not pistils, said of a male flower or plant (hence not seed-bearing).
stellate-pubescent— Having a coat of fine, star-shaped, branched hairs.
stigma— The receptive part of the pistil, on which the pollen germinates.
stipe— The stalk beneath an ovary.
stoloniferous— Having stolons, that is, modified stems that bend over and root at the nodes.
stomate— A small opening on the surface of a leaf through which gaseous exchange takes place.
stoops— Long dives by birds (e.g., raptors) either in combat, in courtship, or in pursuit of prey.
strap-shaped— In the form of a narrow, flat strip with straight sides.
strata— Plural of stratum, which is a tubular or sheetlike body or layer.
stratigraphic— Refers to layered rocks.
stratocumulus— A common low cloud type that is predominantly horizontal with cumuliform lumps.
stratus— A principal low cloud type that is nearly horizontal, commonly obscures higher terrain, and consists of water droplets.
striate— Marked with fine, longitudinal lines or furrows.
stridulation— Buzzing, trilling, or scratching sound.
strip-bark growth— Concentration of the living cambium and bark along one upright section of the tree trunk, with wood exposed along the remainder of the trunk; characteristic of conifers living in the Subalpine Zone.
subduction— The process of one lithospheric plate (crustal layer) descending beneath another.
subglabrous— With almost no hairs present or almost smooth; usually pertains to leaf surface.
subspecies— A group of organisms ranked below a species.
substrate— The surface an animal clings to or walks on; the substance, base, or nutrient on which, or the medium in which, an organism lives and grows, or the surface to which a fixed organism is attached (e.g., soil, rocks, leaves).
subtended— Below and close to.
subterminal— Almost terminal in position.
succession— A series of strata that succeed one another in chronologic order.
succulent— Juicy, fleshy, somewhat soft.
supercooled— Refers to cloud particles that remain in liquid form at temperatures below freezing (i.e., lower than 32°F or 0°C).
supraocular scales— Scales above the eyes.
symbiotic— Refers to organisms that live in continuous beneficial contact with one another.
sympatric— Occurring together in one locality or region.
synclinal— A fold the core of which contains the stratigraphically younger rocks.
synoptic— Pertaining to an overall view at a given instant; in meteorology, it usually refers to weather maps resulting from analyses of observations and measurements made at the same time at many locations.
Tahoe event— A period of glaciation in the Sierra Nevada, occurring at the same time as the Perry Aiken glaciation in the White Mountains, approximately 18,000–140,000 years before the present. Questionably correlated with the midcontinental Illinoian glaciation.
talisman— Object believed to possess supernatural or magical properties.
talus— Accumulations of unstable rock fragments below steep slopes or cliffs.
taproot— A primary stout, vertical root that gives off small laterals but does not divide.
tarsus— The segment at the tip of the arthropod leg. (See Fig. 7.3.)
taxonomic rearrangement— An alternative classification scheme of a group of animals or plants.
tectonic— Pertaining to the rock structure and external forms resulting from the deformation of the Earth's crust.
tepals— Petal-like sepals, as in the buckwheats.
tephra— A collective term for all clastic materials ejected from a volcano and transported through the air, including volcanic dust, ash, cinders, lapilli, scoria, pumice, bombs, and blocks.
terete— Circular in cross section and more or less elongated; cylinder shape may be slightly tapering.
ternate— Arranged in threes.
terrigenous— Derived from the land or continent.
thorax— The section of the arthropod body to which the legs are attached. (See Fig. 7.3.)
threatened— As defined in the Endangered Species Act of 1973, refers to any species or subspecies likely to become endangered within the foreseeable future throughout all or a significant part of its range.
thrust (fault)— A reverse fault in which the inclination to the horizontal is 45° or less.
tibia— A leg segment between the femur and the tarsus. (See Fig. 7.3.)
Tioga event— The most recent glaciation of the Sierra Nevada, occurring the same time as the Middle Creek glaciation of the White Mountains, approximately 24,000–12,000 years before the present. Equivalent to the late Wisconsin glaciation of the midcontinent.
toposcale— Refers to phenomena that are closely related to topographic influences and are intermediate in size between mesoscale and microscale.
tor— A high, isolated crag, pinnacle, or rocky peak; commonly formed through periglacial processes.
torpor— Physiological dormancy in warm-blooded animals through lowered body temperature.
tourmaline— A complex group of silicate minerals; commonly associated in igneous rocks and occurring as three-, six-, or nine-sided prisms.
transcurrent fault— A large-scale, strike-slip fault (movement parallel to trend of fault).
tremolite— A monoclinic (i.e., crystal system characterized by either a single or twofold axis of symmetry) mineral of the amphibole group, Ca2 Mg5 Si8 O22 (OH)2 .
trend— The general term for the direction or bearing of a geological feature.
tribe— The division of a plant family. The large families are commonly divided into tribes.
tridentate— Having three teeth at the apex.
trilobite— An extinct marine arthropod belonging to the Class Trilobita, characterized by a three-lobed (head, middle body, and posterior, or tail) ovoid exoskeleton.
trimodal maximum— Having three nearly equal temporal peaks in the annual distribution of quantity, as for precipitation.
trough— A cyclonic (counterclockwise) bend in the horizontal airflow pattern in the synoptic (weather map) scale.
truncate— Squared at the tip or base as if cut off with a straight blade.
tumpline— Beltlike strap fitted to the head to aid in carrying heavy objects or to permit the free use of hands.
turbinate— Top-shaped, inversely conical.
turfy— Descriptive of a piece of soil bound by roots into a thick mat.
umbel— A flower cluster in which the pedicels come from a common point, like the rays of an umbrella. (See Fig. 6.1.)
understory— Plants beneath the tree canopy in woodland or forest, commonly composed of shrubs, herbs, and juvenile trees.
ungulate— A hooved grazing animal.
uplift— A structurally high area in the crust, produced by positive movements that raise or thrust the rocks upward.
uranium fission— A geological dating method in which the splitting of the nucleus of a uranium atom results in the emission of energy and physical damage to the mineral structure. The number of fission tracks (damaged paths) is indicative of time.
vagrant— An animal occurring outside of its normal distribution.
valve— One of the segments into which a capsule or pod separates, as in the Pea and Mustard families.
vascular— The higher plants, having specialized conducting systems that include xylem (inner two wood elements) and phloem (outer of two tissues).
vegetative reproduction— In seed plants, reproduction by means other than seeds. In other organisms, reproduction by vegetative spores, fragmentation, or division of the somatic cells (cells of the body that compose tissues, organs, and other parts of the individual). Unless a mutation occurs, each daughter cell or individual is genetically identical with its parent. (See also clones .)
ventral— Pertains to the underside, or belly, of an organism.
ventral (pelvic) fins— Paired fins located ventrally anterior to the anus.
vermiculations— Wavy, wormlike markings on the back of Eastern Brook Trout (char).
vermiform— Worm-shaped or wormlike.
volcanic tuff— Fine detritus of volcanic rock fused by heat.
voracious— Having a very large appetite.
wall rock— The rock mass making up the wall of a fault or the rock forming the walls of a vein or mineral deposit.
whorl— A ring of similar organs radiating from a node, as a whorl of leaves.
wind shear— Abrupt change in wind velocity (direction and speed) with height or horizontal distance.
wing— A thin, usually transparent or papery extension bordering an organ, as a winged seed; also, a lateral petal of a pealike flower, e.g., Family Fabaceae.
winnowing— A step in seed processing in which wind and/or gravity are used to separate seeds from unwanted plant material, such as chaff.
xerophytic— Having to do with xerophytes, plants that lose very little water and can grow in deserts or in very dry conditions.