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  • Adaptation- Behavioral or physical characteristic that helps a plant or animal to survive and reproduce in an environment
  • Alternate- Refers to the leaf arrangement; leaves arranged alternately from each other along the stem
  • Amphibian- Cold blooded animals that spend part of their life on land and part of their life in water
  • Angiosperm- Flowering vascular plant
  • Anther- Male part of the flower located at the end of the stamen where pollen develops
  • Areole- A modified leaf bud that defines members of the Cacti Family. Spines, flowers, or roots can originate from this growth region.
  • Asexual Reproduction- Offspring from a single parent resulting in an exact genetic copy of the parent (clone)

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  • Behavioral Adaptation- An adaptation that is behavioral in nature e.g. nocturnal
  • Bimodal Rain Pattern- Two rainy seasons per year
  • Biodiversity- Variety of life
  • Bosque- Dense stands of trees- often refers to Mesquite stands
  • Bulbil- Plantlet produced asexually from parent plant; in the case of agave the bulbil is produced on the flower stalk
  • Burrow- Tunnel or hole; often underground
  • Butte- Steep hill with a flat top; generally smaller than a mesa

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  • Cacti- Plant that usually has a succulent stem and spines on areoles and no leaves
  • Caliche- Layers of very hard soil particles bound by calcium carbonate, found in arid regions; usually light colored
  • Calyx- Outer part of flower structure consisting of sepals; can be used as a cutting tool
  • Camouflage- Coloration or patterns that disguise an organism by enabling it to resemble its surroundings
  • Carnivore- Animal that eats primarily meat
  • Chaparral- A dense shrub plant community that is adapted to frequent fires
  • Chlorophyll- Green pigment that captures light energy during photosynthesis
  • Chromosome-Gene carrying structure found in cells
  • Climate- Meteorological conditions that characterize a region
  • Cochineal- An insect that feeds on prickly pear pads and whose body produces a red color, which can be used as a dye
  • Columnar Cacti- Tall and columnar form of cacti
  • Compound Leaf- A leaf in which the leaf blade is divided into smaller leaflets
  • Condensation- Change of state from a gas or vapor to a liquid
  • Consumer- Organism that feeds on other organisms
  • Convergent Evolution- Term used to describe a process where distant plant families evolve adaptations that a very similar
  • Cotyledon- Food storage structure found in a seed
  • Cultivated- Developed or improved by human care

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  • Decompose- Organism that breaks down organic material into recyclable pieces
  • Desert- An ecosystem where water is a limiting factor most of the time.  Deserts receive less than ten inches of water a year, have extreme temperature fluctuations over a 24 hour period, and have a high evaporation rate
  • Dichotomous Key- Tool used to identify organisms in the natural world by providing the user with a series of two choices that lead to the identity of the organism.
  • Diurnal- Organism that is active during the day
  • DNA- Deoxyribonucleic acid is genetic information organisms inherit from their parents
  • Dominant- The gene responsible for the trait that will be visible in the organism
  • Dormancy- Survival strategy of living organisms wherein growth and development is temporarily suspended
  • Drought Deciduous- Refers to some plants’ ability to drop their leaves during times of drought

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  • Ectothermic- Organism that regulates its body temperature through its surroundings (e.g. cold-blooded)
  • Elliptical- Refers to the shape of the leaf; largest at the center and tapered at both ends
  • Embryo- Immature plant
  • Environment- A system of living and nonliving things interacting together
  • Environmental Conditions- Conditions such as temperature, rainfall, evaporation, and seasons that define an environment.
  • Epidermis- The outer tissue layer of a plant
  • Estivatation- Period of inactivity in response to heat and dryness
  • Ethnobotany- The study of the relationship between plants and people
  • Evaporation- Process through which a liquid changes into a gas

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  • Family- Classification level in the organization of the Plant Kingdom
  • Fertilization- When a sperm unites with the egg
  • Filament- Male part of the flower; stalk portion of the stamen
  • Food web- Interconnections between producers, predators, and prey in an ecosystem
  • Fruit- Mature ovary that contains seeds

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  • Gamete- Reproductive cell (e.g. egg or sperm cell)
  • Gene- A unit of DNA sequence that carries genetic information
  • Gene Expression- Process that determines which genes are visible or expressed
  • Generalist- Organism that can thrive in a variety of environmental conditions and take advantage of a variety of resources
  • Genetics- The science of heredity
  • Germinate- The beginning of growth for a seed; root (radical) emergence
  • Global Air Movement- Pattern of air movement around the globe that influences the location of deserts
  • Glochid- Easily detachable tiny, hair-like bristles particular to opuntioid cacti e.g. prickly pear

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  • Habitat- A place where an organism lives, everything needed to survive can be found within the habitat
  • Herbivore- An animal that eats plants
  • Heredity- Genetic makeup of an individual, which is passed on through generations
  • Hibernate- Spending a season in a state of inactivity
  • Humidity- Amount of water vapor in the air
  • Hygrometer- Device used to measure relative humidity
  • Hypothesis- Possible explanation to answer a question

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  • Inquiry Process- Method of investigation involving observing, questioning, hypothesizing, predicting, experimenting & collecting data, analyzing results, making conclusions, and sharing results (also scientific method or scientific process)
  • Interior Effect- Pattern of air movement that pushes moisture over a continent, as it moves further inland without a source to replenish creating arid regions which influences where deserts are located
  • Investigate- To make a detailed inquiry

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  • Jointed Cacti- Cacti of the Opuntia genus (prickly pear) grow in segmented joints.  These cacti also bear glochids from their areoles.

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  • Keystone Species- A living organism that plays a disproportionately important role in its environment

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  • Leaflets- Each of the veined, leaf-like structures that make up part of a compound leaf.
  • Legume- Fruit that is a single chambered capsule enclosing what appears to be a single row of seeds (that is actually 2 rows); more commonly identified as a bean pod
  • Linear- Refers to the shape of the leaf; one continuous elongated shape
  • Life Cycle-Stages of an organism’s life
  • Limiting Factor- An environmental factor that limits the growth, abundance, or distribution of a population of organisms in an ecosystem
  • Lobed- Refers to the shape of the leaf; divided into rounded sections that aren’t completely separated

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  • Mammal- Warm-blooded vertebrates with hair; young are usually born live and nourished by milk from their mother
  • Marginal Teeth- Teeth-like edges on the side of the leaf
  • Metachromatism- Change in color usually as a result of temperature
  • Metamorphosis- Physical transformation undergone by some animals from one life stage to the next
  • Microphylly- Having small leaves; adaptation to desert environment that reduces water loss and overheating
  • Molt- Process arthropods undergo where they shed their exoskeleton and secrete a new one
  • Monsoon Rain- Seasonal shift in winds which causes a dramatic increase of rain in the summer months

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  • Nectar- Sweet liquid secreted by flowers to reward pollinators
  • Niche- Organism’s ecological role in its environment
  • Nocturnal- Organism that is active at night
  • Nurse Plant- Adult plant that protects young plants from environmental extremes

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  • Observation- Receiving knowledge of the outside world through the senses
  • Omnivore- Animal that eats both plants and animals
  • Opposite- Refers to the leaf arrangement; leaves are arranged in pairs opposite of each other on the stem
  • Osmosis- Movement of water from area of high concentration to low concentration through a cellular membrane
  • Ovary- Female part of the flower containing the ovules and female gametes
  • Ovules- Structures within a plant’s ovary that develop into seeds

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  • Palmate- Refers to the shape of the leaf; having three or more divisions like the outspread of your fingers
  • Petal- Often colorful part of a flower that attracts pollinators
  • Photosynthesis- Series of chemical reactions in which light energy is converted to usable carbohydrates by a plant 6CO2+light+12H2O=C6H12O6+6O2 +6H2O
  • Physical Adaptation- Physical features of an organism that helps it to survive and thrive in its environment e.g. succulence
  • Pinnate- Refers to the arrangement of the leaf; leaf with a feather-like arrangement of leaflets
  • Pistil- Female reproductive unit, consisting of stigma, style, and ovary
  • Pitch- Substance produced by mesquite trees that can be used as a black paint
  • Pollen- Male sperm cells produced by plants and found on the anthers
  • Pollinator- Organism that transfers pollen grains from a stamen to a pistil
  • Pollination- Transfer of pollen grains from a stamen to a pistil
  • Precipitation- Any form of water, including snow or hail, which falls to the earth’s surface
  • Predator- Organism that kills and eats other organisms
  • Prediction- Expected outcome if the hypothesis is true; if/ then statement
  • Prey- Organism that is killed and eaten by another organism
  • Primary Consumer- Organism that gets its energy from plants; herbivore
  • Producer- Organism that produces its own food, often a plant; first step of a food chain
  • Punnett Square- A diagram used to predict the probability of a genetic trait being visible (phenotype) in a cross
  • Pup- Asexual offspring of parent plant, which is produced and sent up from the roots e.g. agave pups

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  • Question- A request for information; inquiry

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  • Rain Shadow- Area of reduced precipitation on the lee side of a mountain
  • Recessive- Trait that will be masked by a dominant form of that trait
  • Reptile- Cold blooded vertebrate that has scales or plates on its skin and usually lays eggs
  • Resin- Sticky substances produced by plants that can have ethnobotanical uses
  • Ribs- Pleated structures on the stems of some columnar cacti
  • Riparian- Habitat interface between land and freshwater (usually a river or stream)
  • Roots- Part of a plant usually under ground that anchors the plant and collects water

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  • Saguaro Boot- Damaged tissue of saguaro cactus which is scabbed over and may serve as a home for desert organisms; usually a result of woodpecker damage
  • Scalloped leaf- Edges of leaf rounded like a pie crust
  • Scientific Method- Method of investigation involving observing, questioning, hypothesizing, predicting, experimenting & collecting data, analyzing results, making conclusions, and sharing results (also inquiry process or scientific process)
  • Scientific Process- Method of investigation involving observing, questioning, hypothesizing, predicting, experimenting & collecting data, analyzing results, making conclusions, and sharing results (also inquiry process or scientific method)
  • Secondary Consumer- Organism that feeds on other consumers; carnivore
  • Seed- Reproductive structure of a seed plant
  • Seed Coat- The outer, protective layer that covers the seed
  • Seed Dispersal- Movement of seeds away from the parent plant
  • Seed Dormancy- Delayed germination of seeds
  • Serrate Leaf- Leaf which has sawtoothed margins
  • Sexual Reproduction- The union of gametes from two different individuals resulting in genetic diversity
  • Simple Leaf- Undivided leaf
  • Specialist- Organism that has a limited diet
  • Spine- Modified leaf which is hard and has a sharp point
  • Stamen- Male reproductive part of the flower consisting of an anther and a filament
  • Stem- Above ground part of the plant through which water and nutrients flow
  • Stigma- Female part of a flower; end of the style that captures pollen
  • Stoma- Adjustable pore on the epidermis of a leaf that controls gas exchange
  • Stomata- Plural of stoma
  • Style- Female part of a flower; elongated part of the pistil between the ovary and the stigma
  • Succulence- Ability of plants to store water in stems, leaves, or roots
  • Succulents- Plants that have the ability to store water in stems, leaves, or roots
  • Symbiosis- A close association between two species

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  • Taproot- Main vertical root of some plant’s root systems e.g. carrot
  • Terminal Spine- Spine at the top of the leaf
  • Thermals- Column of rising warm air caused by uneven heating of the Earth’s surface
  • Thermoregulation- Biological mechanism that keeps organism’s internal temperature within normal limits
  • Thorn- Hard, modified stem or branch which ends in a sharp point
  • Trait- Characteristic or feature of an organism
  • Transpiration- Evaporation of water through the stomata of leaves

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  • Urban Heat Island- Metropolitan area which is significantly warmer than the surrounding rural area


  • Vegetative Reproduction- Asexual reproduction

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  • Wash- Landscape feature which may carry surface water during rainy months
  • Water Vapor- Water in gas phase
  • Weather- State of the atmosphere at a specific time and place

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