Glossary

abiotic

nonliving

abrade

to wear away through contact

abrasive

tending to wear away through contact

abscission

dropping off or separating

accession

a plant that has been acquired and catalogued

achene

a small, dry, thin-walled type of fruit

actinomycetes

common name for a group of Gram-positive bacteria that are filamentous and superficially similar to fungi

addictive

capable of causing addiction or chemical dependence

adhesion

sticking to the surface of

adventitious

arising from secondary buds, or arising in an unusual position

aeration

the introduction of air

albuminous

gelatinous, or composed of the protein albumin

alkali

chemically basic; the opposite of acidic

alkalinization

increase in basicity or reduction in acidity

alkaloid

bitter secondary plant compound, often used for defense

allele

one form of a gene

allelopathy

harmful action by one plant against another

allopolyploidy

a polyploid organism formed by hybridization between two different species or varieties (allo = other)

alluvial plain

broad area formed by the deposit of river sediment at its outlet

amended soils

soils to which fertilizers or other growth aids have been added

amendment

additive

anaerobic

without oxygen

analgesic

pain-relieving

analog

a structure or thing, especially a chemical, similar to something else

angiosperm

a flowering plant

anomalous

unusual or out of place

anoxic

without oxygen

antenna system

a collection of protein complexes that harvests light energy and converts it to excitation energy that can migrate to a reaction center; the light is absorbed by pigment molecules (e.g., chlorophyll, carotenoids, phycobilin) that are attached to the protein

anthropogenic

human-made; related to or produced by the influence of humans on nature

antibodies

proteins produced to fight infection

antioxidant

a substance that prevents damage from oxygen or other reactive substances

apical meristem

region of dividing cells at the tips of growing plants

apical

at the tip

apomixis

asexual reproduction that may mimic sexual reproduction

appendages

parts that are attached to a central stalk or axis

arable

able to be cultivated for crops

Arcto-Tertiary geoflora

the fossil flora discovered in Arctic areas dating back to the Tertiary period; this group contains magnolias (Magnolia), tulip trees (Liriodendron), maples (Acer), beech (Fagus), black gum (Nyssa), sweet gum (Liquidambar), dawn redwood (Metasequoia), cypress (Taxodium), and many other species

artifacts

pots, tools, or other cultural objects

assayer

one who performs chemical tests to determine the composition of a substance

ATP

adenosine triphosphate, a small, water-soluble molecule that acts as an energy currency in cells

attractant

something that attracts

autotroph

"self-feeder"; any organism that uses sunlight or chemical energy

auxin

a plant hormone

avian

related to birds

axil

the angle or crotch where a leaf stalk meets the stem

axillary bud

the bud that forms in the angle between the stem and leaf

basipetal

toward the base

belladonna

the source of atropine; means "beautiful woman," and is so named because dilated pupils were thought to enhance a woman's beauty

binomial

two-part

biodirected assays

tests that examine some biological property

biodiversity

degree of variety of life

biogeography

the study of the reasons for the geographic distribution of organisms

biomass

the total dry weight of an organism or group of organisms

biosphere

the region of the Earth in which life exists

biosynthesis

creation through biological pathways

biota

the sum total of living organisms in a region of a given size

biotic

involving or related to life

bryologist

someone who studies bryophytes, a division of nonflowering plants

campanulate

bell-shaped

capitulum

the head of a compound flower, such as a dandelion

cardiotonic

changing the contraction properties of the heart

carotenoid

a yellow-colored molecule made by plants

carpels

the innermost whorl of flower parts, including the egg-bearing ovules, plus the style and stigma attached to the ovules

catastrophism

the geologic doctrine that sudden, violent changes mark the geologic history of Earth

cation

positively charged particle

catkin

a flowering structure used for wind pollination

centrifugation

spinning at high speed in a centrifuge to separate components

chitin

a cellulose-like molecule found in the cell wall of many fungi and arthropods

chloroplast

the photosynthetic organelle of plants and algae

circadian

"about a day"; related to a day

circumscription

the definition of the boundaries surrounding an object or an idea

cisterna

a fluid-containing sac or space

clade

a group of organisms composed of an ancestor and all of its descendants

cladode

a modified stem having the appearance and function of a leaf

coalescing roots

roots that grow together

coleoptile

the growing tip of a monocot seedling

collenchyma

one of three cell types in ground tissue

colonize

to inhabit a new area

colony

a group of organisms inhabiting a particular area, especially organisms descended from a common ancestor

commensalism

a symbiotic association in which one organism benefits while the other is unaffected

commodities

goods that are traded, especially agricultural goods

community

a group of organisms of different species living in a region

compaction

compacting of soil, leading to the loss of air spaces

complex hybrid

hybridized plant having more than two parent plants

compound

a substance formed from two or more elements

concentration gradient

a difference in concentration between two areas

continental drift

the movement of continental land masses due to plate tectonics

contractile

capable of contracting

convective uplift

the movement of air upwards due to heating from the sun

coppice growth

the growth of many stems from a single trunk or root, following the removal of the main stem

cortical

relating to the cortex of a plant

covalent

held together by electron-sharing bonds

crassulacean acid metabolism

water-conserving strategy used by several types of plants

crop rotation

alternating crops from year to year in a particular field

cultivation

growth of plants, or turning the soil for growth of crop plants

crystallography

the use of x-rays on crystals to determine molecular structure

cuticle

the waxy outer coating of a leaf or other structure, which provides protection against predators, infection, and water loss

cyanide heap leach gold mining

a technique used to extract gold by treating ore with cyanide

cyanobacteria

photosynthetic prokaryotic bacteria formerly known as blue-green algae

cyanogenic

giving rise to cyanide

cytologist

a scientist who studies cells

cytology

the microscopic study of cells and cell structure

cytosol

the fluid portion of a cell

cytostatic

inhibiting cell division

deductive

reasoning from facts to conclusion

dendrochronologist

a scientist who uses tree rings to determine climate or other features of the past

dermatophytes

fungi that cause skin diseases

desertification

degradation of dry lands, reducing productivity

desiccation

drying out

detritus

material from decaying organisms

diatoms

hard-shelled, single-celled marine organisms; a type of algae

dictyosome

any one of the membranous or vesicular structures making up the Golgi apparatus

dioicous

having male and female sexual parts on different plants

diploid

having two sets of chromosomes, versus having one set (haploid)

dissipate

to reduce by spreading out or scattering

distal

further away from

diurnal

daily, or by day

domestication

the taming of an organism to live with and be of use to humans

dormant

inactive, not growing

drupe

a fruit with a leathery or stone-like seed

dynamical system theory

the mathematical theory of change within a system

ecophysiological

related to how an organism's physiology affects its function in an ecosystem

ecosystem

an ecological community and its environment

elater

an elongated, thickened filament

empirical formula

the simplest whole number ratio of atoms in a compound

emulsifier

a chemical used to suspend oils in water

encroachment

moving in on

endemic

belonging or native to a particular area or country

endophyte

a fungus that lives within a plant

endoplasmic reticulum

the membrane network inside a cell

endosperm

the nutritive tissue in a seed, formed by the fertilization of a diploid egg tissue by a sperm from pollen

endosporic

the formation of a gametophyte inside the spore wall

endosymbiosis

a symbiosis in which one organism lives inside the other

Enlightenment

eighteenth-century philosophical movement stressing rational critique of previously accepted doctrines in all areas of thought

entomologist

a scientist who studies insects

enzyme

a protein that controls a reaction in a cell

ephemeral

short-lived

epicuticle

the waxy outer covering of a plant, produced by the epidermis

epidermis

outer layer of cells

epiphytes

plants that grow on other plants

escarpment

a steep slope or cliff resulting from erosion

ethnobotanist

a scientist who interacts with native peoples to learn more about the plants of a region

ethnobotany

the study of traditional uses of plants within a culture

euglossine bees

a group of bees that pollinate orchids and other rain-forest plants

eukaryotic

a cell with a nucleus (eu means "true" and karyo means "nucleus"); includes protists, plants, animals, and fungi

extrafloral

outside the flower

exudation

the release of a liquid substance; oozing

facultative

capable of but not obligated to

fertigation

application of small amounts of fertilizer while irrigating

filament

a threadlike extension

filamentous

thin and long

flagella

threadlike extension of the cell membrane, used for movement

flavonoids

aromatic compounds occurring in both seeds and young roots and involved in host-pathogen and host-symbiont interactions

florigen

a substance that promotes flowering

floristic

related to plants

follicle

sac or pouch

forbs

broad-leaved, herbaceous plants

free radicals

toxic molecular fragments

frugivous

feeding on fruits

gametangia

structure where gametes are formed

gametophyte

the haploid organism in the life cycle

gel electrophoresis

a technique for separating molecules based on size and electrical charge

genera

plural of genus; a taxonomic level above species

genome

the genetic material of an organism

genotype

the genetic makeup of an organism

germplasm

hereditary material, especially stored seed or other embryonic forms

globose

rounded and swollen; globe-shaped

gradient

difference in concentration between two places

green manure

crop planted to be plowed under to nourish the soil, especially with nitrogen

gymnosperm

a major group of plants that includes the conifers

gynoecium

the female reproductive organs as a whole

gypsipherous

containing the mineral gypsum

hallucinogenic

capable of inducing hallucinations

haploid

having one set of chromosomes, versus having two (diploid)

haustorial

related to a haustorium, or food-absorbing organ

hemiterpene

a half terpene

herbivore

an organism that feeds on plant parts

heterocyclic

a chemical ring structure composed of more than one type of atom, for instance carbon and nitrogen

heterosporous

bearing spores of two types, large megaspores and small microspores

heterostylous

having styles (female flower parts) of different lengths, to aid cross-pollination

heterotroph

an organism that derives its energy from consuming other organisms or their body parts

holistic

including all the parts or factors that relate to an object or idea

homeotic

relating to or being a gene that produces a shift in structural development

homology

a similarity in structure between anatomical parts due to descent from a common ancestor

humus

the organic material in soil formed from decaying organisms

hybrid

a mix of two varieties or species

hybridization

formation of a new individual from parents of different species or varieties

hydrological cycle

the movement of water through the biosphere

hydrophobic

water repellent

hydroponic

growing without soil, in a watery medium

hydroxyl

the chemical group -OH

hyphae

the threadlike body mass of a fungus

illicit

illegal

impede

to slow down or inhibit

inert

incapable of reaction

inflorescence

a group of flowers or arrangement of flowers in a flower head

infrastructure

roads, phone lines, and other utilities that allow commerce

insectivorous

insect-eating

intercalary

inserted; between

interspecific hybridization

hybridization between two species

intertidal

between the lines of high and low tide

intracellular bacteria

bacteria that live inside other cells

intraspecific taxa

levels of classification below the species level

intuiting

using intuition

ionic

present as a charged particle

ions

charged particles

irreversible

unable to be reversed

juxtaposition

contrast brought on by close positioning

lacerate

cut

Lamarckian inheritance

the hypothesis that acquired characteristics can be inherited

lamellae

thin layers or plate-like structure

land-grant university

a state university given land by the federal government on the condition that it offer courses in agriculture

landrace

a variety of a cultivated plant, occurring in a particular region

lateral

to the side of

legume

beans and other members of the Fabaceae family

lignified

composed of lignin, a tough and resistant plant compound

lineage

ancestry; the line of evolutionary descent of an organism

loci

(singular: locus) sites or locations

lodging

falling over while still growing

lytic

breaking apart by the action of enzymes

macromolecule

a large molecule such as a protein, fat, nucleic acid, or carbohydrate

macroscopic

large, visible

medulla

middle part

megaphylls

large leaves having many veins or a highly branched vein system

meiosis

the division of chromosomes in which the resulting cells have half the original number of chromosomes

meristem

the growing tip of a plant

mesic

of medium wetness

microfibrils

microscopic fibers in a cell

micron

one millionth of a meter; also called micrometer

microphylls

small leaves having a single unbranched vein

mitigation

reduction of amount or effect

mitochondria

cell organelles that produce adenosine triphosphate (ATP) to power cell reactions

mitosis

the part of the cell cycle in which chromosomes are separated to give each daughter cell an identical chromosome set

molecular systematics

the analysis of DNA and other molecules to determine evolutionary relationships

monoculture

a large stand of a single crop species

monomer

a single unit of a multi-unit structure

monophyletic

a group that includes an ancestral species and all its descendants

montane

growing in a mountainous region

morphology

shape and form

motile

capable of movement

mucilaginous

sticky or gummy

murein

a peptidoglycan, a molecule made up of sugar derivatives and amino acids

mutualism

a symbiosis between two organisms in which both benefit

mycelium

the vegetative body of a fungus, made up of threadlike hyphae

NADP⁺

oxidized form of nicotinamide adenine dinucleotide phosphate

NADPH

reduced form of nicotinamide adenine dinucleotide phosphate, a small, water-soluble molecule that acts as a hydrogen carrier in biochemical reactions

nanometer

one billionth of a meter

nectaries

organs in flowers that secrete nectar

negative feedback

a process by which an increase in some variable causes a response that leads to a decrease in that variable

neuromuscular junction

the place on the muscle surface where the muscle receives stimulus from the nervous system

neurotransmitter

a chemical that passes messages between nerve cells

node

branching site on a stem

nomenclature

a naming system

nonmotile

not moving

nonpolar

not directed along the root-shoot axis, or not marked by separation of charge (unlike water and other polar substances)

nonsecretory

not involved in secretion, or the release of materials

Northern Blot

a technique for separating RNA molecules by electrophoresis and then identifying a target fragment with a DNA probe

nucleolar

related to the nucleolus, a distinct region in the nucleus

nurseryman

a worker in a plant nursery

obligate

required, without another option

obligate parasite

a parasite without a free-living stage in the life cycle

odorant

a molecule with an odor

organelle

a membrane-bound structure within a cell

osmosis

the movement of water across a membrane to a region of high solute concentration

oviposition

egg-laying

oxidation

reaction with oxygen, or loss of electrons in a chemical reaction

paleobotany

the study of ancient plants and plant communities

pangenesis

the belief that acquired traits can be inherited by bodily influences on the reproductive cells

panicle

a type of inflorescence (flower cluster) that is loosely packed and irregularly branched

paraphyletic group

a taxonomic group that excludes one or more descendants of a common ancestor

parenchyma

one of three types of cells found in ground tissue

pastoralists

farming people who keep animal flocks

pathogen

disease-causing organism

pedicel

a plant stalk that supports a fruiting or spore-bearing organ

pentamerous

composed of five parts

percolate

to move through, as a fluid through a solid

peribacteroid

a membrane surrounding individual or groups of rhizobia bacteria within the root cells of their host; in such situations the bacteria have frequently undergone some change in surface chemistry and are referred to as bacteroids

pericycle

cell layer between the conducting tissue and the endodermis

permeability

the property of being permeable, or open to the passage of other substances

petiole

the stalk of a leaf, by which it attaches to the stem

pH

a measure of acidity or alkalinity; the pH scale ranges from 0 to 14, with 7 being neutral. Low pH numbers indicate high acidity while high numbers indicate alkalinity

pharmacognosy

the study of drugs derived from natural products

pharmacopeia

a group of medicines

phenology

seasonal or other time-related aspects of an organism's life

pheromone

a chemical released by one organism to influence the behavior of another

photooxidize

to react with oxygen under the influence of sunlight

photoperiod

the period in which an organism is exposed to light or is sensitive to light exposure, causing flowering or other light-sensitive changes

photoprotectant

molecules that protect against damage by sunlight

phylogenetic

related to phylogeny, the evolutionary development of a species

physiology

the biochemical processes carried out by an organism

phytogeographer

a scientist who studies the distribution of plants

pigments

colored molecules

pistil

the female reproductive organ of a flower

plasmodesmata

cell-cell junctions that allow passage of small molecules between cells

polyculture

mixed species

polyhedral

in the form of a polyhedron, a solid whose sides are polygons

polymer

a large molecule made from many similar parts

polynomial

"many-named"; a name composed of several individual parts

polyploidy

having multiple sets of chromosomes

polysaccharide

a linked chain of many sugar molecules

population

a group of organisms of a single species that exist in the same region and interbreed

porosity

openness

positive feedback

a process by which an increase in some variable causes a response that leads to a further increase in that variable

precipitation

rainfall; or the process of a substance separating from a solution

pre-Columbian

before Columbus

precursor

a substance from which another is made

predation

the act of preying upon; consuming for food

primordial

primitive or early

progenitor

parent or ancestor

prokaryotes

single-celled organisms without nuclei, including Eubacteria and Archaea

propagate

to create more of through sexual or asexual reproduction

protist

a usually single-celled organism with a cell nucleus, of the kingdom Protista

protoplasmic

related to the protoplasm, cell material within the cell wall

protoplast

the portion of a cell within the cell wall

psychoactive

causing an effect on the brain

pubescence

covered with short hairs

pyruvic acid

a three-carbon compound that forms an important intermediate in many cellular processes

quadruple hybrid

hybridized plant with four parents

quantitative

numerical, especially as derived from measurement

quid

a wad for chewing

quinone

chemical compound found in plants, often used in making dyes

radii

distance across, especially across a circle (singular = radius)

radioisotopes

radioactive forms of an element

rambling habit

growing without obvious intended direction

reaction center

a protein complex that uses light energy to create a stable charge separation by transferring a single electron energetically uphill from a donor molecule to an acceptor molecule, both of which are located in the reaction center

redox

oxidation and reduction

regurgitant

material brought up from the stomach

Renaissance

a period of artistic and intellectual expansion in Europe from the fourteenth to the sixteenth century

salinization

increase in salt content

samara

a winged seed

saprophytes

plants that feed on decaying parts of other plants

saturated

containing as much dissolved substance as possible

sclerenchyma

one of three cell types in ground tissue

sedimentation

deposit of mud, sand, shell, or other material

semidwarf

a variety that is intermediate in size between dwarf and full-size varieties

senescent

aging or dying

sepals

the outermost whorl of flower parts; usually green and leaf-like, they protect the inner parts of the flower

sequester

to remove from circulation; lock up

serology

the study of serum, the liquid, noncellular portion of blood

seta

a stiff hair or bristle

silage

livestock food produced by fermentation in a silo

siliceous

composed of silica, a mineral

silicified

composed of silicate minerals

soil horizon

distinct layers of soil

solute

a substance dissolved in a solution

Southern blot

a technique for separating DNA fragments by electrophoresis and then identifying a target fragment with a DNA probe

spasticity

abnormal muscle activity caused by damage to the nerve pathways controlling movement

speciation

the creation of new species

specimen

an object or organism under consideration

speciose

marked by many species

sporophyte

the diploid, spore-producing individual in the plant life cycle

sporulate

to produce or release spores

sterile

not capable or involved in reproduction, or unable to support life

sterols

chemicals related to steroid hormones

stolons

underground stems that may sprout and form new individuals

stomata

openings between guard cells on the underside of leaves that allow gas exchange

stratification

layering, or separation in space

stratigraphic geology

the study of rock layers

stratigraphy

the analysis of strata (layered rock)

strobili

cone-like reproductive structures

subalpine

a region less cold or elevated than alpine (mountaintop)

substrate

the physical structure to which an organism attaches, or a molecule acted on by enzymes

succession

the pattern of changes in plant species that occurs after a soil disturbance

succulent

fleshy, moist

suckers

naturally occuring adventitious shoots

suffrutescent

a shrub-like plant with a woody base

sulfate

a negatively charged particle combining sulfur and oxygen

surfaced

smoothed for examination

susceptibility

vulnerability

suture

line of attachment

swidden agriculture

the practice of farming an area until the soil has been depleted and then moving on

symbiont

one member of a symbiotic association

symbiosis

a relationship between organisms of two different species in which at least one benefits

systematists

scientists who study systematics, the classification of species to reflect evolutionary relationships

systemic

spread throughout the plant

tannins

compounds produced by plants that usually serve protective functions, often colored and used for "tanning" and dyeing

taxa

a type of organism, or a level of classification of organisms

tensile forces

forces causing tension, or pulling apart; the opposite of compression

tepal

an undifferentiated sepal or petal

Tertiary period

geologic period from sixty-five to five million years ago

tetraploid

having four sets of chromosomes; a form of polyploidy

thallus

simple, flattened, nonleafy plant body

tilth

soil structure characterized by open air spaces and high water storage capacity due to high levels of organic matter

tonoplast

the membrane of the vacuole

topographic

related to the shape or contours of the land

totipotent

capable of forming entire plants from individual cells

toxin

a poisonous substance

tracheid

a type of xylem cell that conducts water from root to shoot

transcription factors

proteins that bind to a specific DNA sequence called the promoter to regulate the expression of a nearby gene

translocate

to move materials from one region to another

translucent

allowing the passage of light

transmutation

to change from one form to another

transpiration

movement of water from soil to atmosphere through a plant

transverse

across, or side to side

tribe

a group of closely related genera

trophic

related to feeding

turgor pressure

the outward pressure exerted on the cell wall by the fluid within

twining

twisting around while climbing

ultrastructural

the level of structure visible with the electron microscope; very small details of structure

uniformitarian

the geologic doctrine that formative processes on earth have proceeded at the same rate through time since earth's beginning

uplift

raising up of rock layers, a geologic process caused by plate tectonics

urbanization

increase in size or number of cities

vacuole

the large fluid-filled sac that occupies most of the space in a plant cell. Used for storage and maintaining internal pressure

vascular plants

plants with specialized transport cells; plants other than bryophytes

vascular

related to the transport of nutrients, or related to blood vessels

vector

a carrier, usually one that is not affected by the thing carried

vernal

related to the spring season

vesicle

a membrane-bound cell structure with specialized contents

viable

able to live or to function

volatile

easily released as a gas

volatilization

the release of a gaseous substance

water table

the level of water in the soil

whorl

a ring

wort

an old English term for plant; also an intermediate liquid in beer making

xenobiotics

biomolecules from outside the plant, especially molecules that are potentially harmful

xeromorphic

a form adapted for dry conditions

xerophytes

plants adapted for growth in dry areas

zonation

division into zones having different properties

zoospore

a swimming spore

zygote

the egg immediately after it has been fertilized; the one-cell stage of a new individual