Glossary; A Natural History

Glossary

altricial Helpless when born or hatched and dependent upon parents for food and care for a period of time. Compare precocial.

angiosperms Flowering vascular plants with seeds enclosed in the ovaries (as compared to gymnosperms, such as conifers, which have "naked" seeds).

annual plant A plant which completes its life cycle from seed germination, through reproduction, to death within one year.

autotomy The self-amputation of a limb or body part in order to escape predation; e.g., a western banded gecko can shed its tail or an immature walkingstick its leg when threatened, then regenerate the excised part, although not perfectly.

biotic community The plants and animals living and interacting with each other and with their physical environment in a given locality, such as in a salt marsh or in a bursage-creosote community.

caldera A landscape feature that is a broad basin-like depression formed by a volcanic explosion or the collapse of a volcanic cone.

chaparral A plant assembly characterized by dense growth of resinous shrubs that readily resprout from roots and seeds following fires— typical of a Mediterranean climate with mostly winter rain.

chiropterophilous plant A plant having features that are attractive to bats, such as pale flowers with musky scents, abundant nectar produced at night and pollen containing amino acids important to bat nutrition; literally, "bat loving".

cienega (sometimes cienaga) Southwestern U.S. and Spanish term referring to a swamp or marsh, especially one fed by springs. (First "e" bears an accent mark in Spanish.)

cohort A group of individuals of the same species or other taxa which start life at approximately the same time, e.g., saguaro cacti that become established during a given period or a population of butterflies that emerge from pupas at the same time. (From military usage.)

commensalism Symbiosis in which one organism benefits at no cost (or benefit) to the other.

community See biotic community.

complete metamorphosis An insect life cycle which includes four distinct morphological stages— egg, larva, pupa and adult.

composite plant A dicotyledenous plant in the family Asteraceae (Compositae); many species bear individual flowers tightly clustered in disk-like or daisy- like heads.

convergent evolution The independent development over time of similar structures by unrelated (or distantly related) species in response to similar environmental factors or stresses, e.g., spines, leaflessness and succulence in both cacti and many African euphorbias.

crepuscular (Zool.) Active in the dim twilight of dusk or dawn; compare nocturnal and diurnal.

cryptic colors Coloration which makes a given species difficult to see in its habitat or which makes it resemble an inedible object such as a pebble.

cryptobiotic soil (also cryptogamic or microphytic crust) The fragile, crusty top layer of many desert soils characterized by the growth of lichens, algae, blue-green algae (cyanobacteria), liverworts, or mosses, in combination or singly.

deciduous plant A plant that drops its leaves annually in response to a dry or cold period.

dicotyledon (dicot) A plant in the larger of two angiosperm classes— the Dicotyledones. The first leaves that emerge from dicot seeds are in a pair. Compare monocotyledon.

dimorphism The state of having two forms which differ in appearance, shape, or size within the same species.

dioecious Having only anther-bearing "male" or carpel-bearing "female" flowers on a given plant. Compare monoecious. diurnal Active during the day.

dormancy The temporary suspension of biological activity, such as growth or movement.

ecology The study of interrelationships among plants, animals and their physical environments.

ecosystem The combined living organisms and non-living physical components of the environment and their relationships in any given area, e.g., a small mud flat or the biosphere; through these energy moves and minerals are recycled.

endemic Growing or living exclusively within a particular region or locality.

ephemeral (Bot.) A plant that germinates, reproduces and dies over a very short period, usually within a few weeks to several months; pertaining to such plants.

estivation (Zool.) A period of torpor or dormancy in response to heat or dryness, especially in summer.

family A taxonomic group consisting of genetically related genera. fledgling The avian life stage in which young birds begin to fly and are able to leave the nest.

flowering plant See angiosperm.

forb A broadleafed flowering plant (as distinguished from a grass or sedge).

fossorial Digging or burrowing.

glochid A readily detachable barbed bristle, usually tiny and hairlike, peculiar to opuntioid cacti.

granivorous Feeding upon grains, seeds.

gravid Pregnant with fetus or eggs.

herbivorous Feeding upon plants or parts of plants.

hibernation (Zool.) A period of dormancy or inactivity in response to cold or drought during which metabolic processes are significantly reduced and body temperature may be greatly lowered.

hybrid Offspring which is the product of cross-fertilization between two different species, subspecies or varieties.

incomplete metamorphosis A life cycle of insects in which the larva hatching from the egg resembles the adult stage but lacks wings; lacking a pupal stage, it changes to the (usually) winged adult form over the course of several molts.

insolation Exposure to the sun.

intar An arthropod in any given stage between molts; or any given stage between arthropod molts.

lagomorph A rabbit or hare.

larva An immature feeding stage of some animals which differs from the adult form.

mesic Of or pertaining to a habitat that has at least a moderate amount of moisture, such as a riparian area or cienega, or adapted to such a habitat. Compare xeric.

metamorphosis The physical (morphological) transformation undergone by various animals from one life stage to the next. See also complete and incomplete metamorphosis.

mimicry (Zool.) The characteristic of resembling something unpalatable, distasteful, or poisonous or otherwise dangerous.

monocotyledon (monocot) A plant in the smaller of two angiosperm classes— Monocotyledones. A single leaf emerges first from the seed. Compare dicotyledon.

monoecious Having separate anther-bearing "male" and carpel-bearing "female" flowers on the same plant. Compare dioecius.

nectarivorous Feeding on flower nectar.

nestling Young altricial bird incapable of flight and dependent on parent for food.

niche The role or function of a particular species in its community or ecosystem.

nocturnal Active at night.

nymph An immature stage in the incomplete metamorphosis of some arthropods which resembles the adult form. Also a butterfly in the genus Satyrus.

omnivore An animal which feeds on both animal and plant material.

orographic Pertaining to mountain-building or orogeny.

oviparous Laying eggs which hatch after leaving the mother. s body.

ovoviviparous Producing eggs which hatch inside the mother. s body so that the young are born with neither a placental attachment nor a shell.

parotoid glands Conspicuous glands behind the ears of toads which secrete poisonous or toxic substances. (These resemble parotid salivary glands which have a similar location.)

pedipalps Leglike appendages in arachnids just behind the mouthparts used in maneuvering prey and during mating.

parasitism Symbiosis in which one organism benefits at the expense of the other.

petiole The stalk of a leaf which attaches to the stem (Bot.). The narrow part of the body, or waist, connecting the abdomen and thorax in a wasp (Zool.)

pinna (pl. pinnae) The primary subdivision of a pinnately compound leaf, a leaflet which may bear other leaflets (pinnules).

playa The floor of a desert basin with interior drainage that becomes a shallow lake after heavy rains.

poison A substance which causes illness or death when ingested (e.g., plant parts or secretions from toad glands).

precocial Born or hatched furred or feathered, with eyes open and able to move away from the birthplace or next relatively soon.

pupa The non-feeding, nonmobile stage in insects between the last larval form and the adult stage, during which the insect undergoes anatomical changes.

sexual reproduction In both plants and animals the process in which two cells with nuclei---one from each of two parents— fuse and the resulting offspring inherits a set of chromosomes from each parent, resulting in a unique individual. Compare parthenogenesis, apomixis, and vegetative reproduction (see listings in the Index).

species richness The number of species in a given area.

spine A hard sharp-pointed modified leaf or part of a leaf.

substrate The surface on which an organism rests or to which it is attached, e.g., a stream bottom, soil surface or leaf.

symbiosis A state in which two different species live together in intimate association; the term is often used to describe relationships that are mutually beneficial, but it also includes other relationships. See commensalism, mutualism and parasitism.

taxon A taxonomic group of any rank or size.

taxonomy The science of classification of plants and animals.

torpor A state of dormancy or inactivity.

venom A substance which may contain hemotoxins and/or neurotoxins and causes pain, paralysis and/or death when injected by mouthparts (including fangs) or stinger.

xeric Of or pertaining to a dry habitat such as a desert, or adapted to such a dry habitat. Compare mesic.