P

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.