Venus flytrap terminology

Learning about carnivorous plants can be fun. It can also be daunting. When describing carnivorous plants, physical structures, mechanisms, relationships with other organisms, etc, we can end up down a rabbit hole of botanical terminology. It’s a specialized language for describing specialized features, and for the uninitiated, it can sound like a foreign language. Throughout Carnivorous Plant Resource, I try to describe things in a simple manner, but I do occasionally leverage terminology pulled from the world of botany simply because it is succinct and the most accurate when you understand what all the big scary words actually mean.

To help clear up any confusion, here’s a list of botanical terms with definitions (click on an item to expand it) and clarifying imagery that I hope guides you through your journey into the fascinating world of carnivorous plants. If I’ve missed a term, please leave a comment and I’ll get it added! Also, consider bookmarking this page for quick reference in the future. You can click on any image to enlarge it.

the side away from the axis, such as the underside of a leaf.

the natural falling off of plant parts such as leaves and flowers induced by biochemical processes in the plant.

the side toward the axis such as the upper side of a leaf.

end part of stamen which bears the pollen

Sarracenia flower anatomy

flowering plants that bear seeds and that develop in an ovary.

a plant that grows from seed, germinates, produces more seed and dies in one growing seasons, which is usually one year.

complex substances responsible for the colors of number plants and flower (such as venation in Sarracenia)

end of a part of a plant which is furthest from its point of attachment

the bud at the tip or apex of a stem.

(plural: areolae) small pit; also used for the translucent windows in Darlingtonia Californica and some Sarracenias.

Windows on Darlingtonia hood
Windows of Sarracenia minor

pitcher-shaped, or with hollow tubular leaves.

angle between stem and upper surface of leaf stalk growing from the stem.

a corolla and/or calyx having two lips.

the trapping structure of Utricularia.

utricularia bladder

small modified leaves often found at base of, or along flowering stems, and sometimes near or on the calyx as in Sarracenia.

Sarracenia flower anatomy

Hairs along the outer edge of the lobes of the trap of Dionaea and Aldrovanda.

Venus flytrap cilia closed

a mass of tissue that will develop into a stem, branch or flower.

the development of a plant from a proliferation of cells.

an underground bud surrounded by scales or leaf bases which enclose it. The so-called Dionaea (Venus flytrap) bulb is not a true bulb, but rather the growing point (apical bud) surrounded by the remaining basal portions of the leaves which have been cut off (see tuber, rhizome).

the outer group of parts of the flower, consisting of the sepals.

Sarracenia flower anatomy

the living tissue just beneath the bark that gives rise to secondary xylem and phloem cells.

in flowering plants the ovule-bearing structure.

having or consisting of carpels.

flowers which are pollinated when open.

the hard material of which the skeleton and wings of insects are composed.

the green coloring matter of plants which enables them to manufacture carbohydrates from carbon dioxide and water by using energy derived from sunlight (aka photosynthesis).

sometimes used to refer to the bristles of the Dionaea trap. We’ve got a blog post honoring this specific structure, here.

Venus flytrap cilia

rolled inwards from apex to base like a watch-spring, as in the embryo leaves of many ferns.

flowers that do not open and therefore, are self-pollinated.

all plants obtained by vegetative propagation from one seedling are said to be of the same clone. In other terms – a group of plants reproduced asexually from one plant and, therefore, genetically identical.

subjecting seeds to cold, moist conditions (often mimicking winter climates in native habitats) for an extended period to stimulate germination.

the neck-like portion of the lowest part of the hood in many Sarracenias.

the collective name for the petals of one flower.

a hollow ‘cylinder’ resulting from the fusion or joining of the petals.

an inflorescence in which the branches and flower stalks are of different lengths which become increasingly shorter up the stem, so that the flower are all held on the same level.

the leaves present in the seeds and the first to appear following germination. These leaves seldom resemble the mature leaves of the plant.

the transfer of pollen from the anther of a flower on one plant to the stigma of a pistil of a flower on another plant.

a plant variety that has been produced in cultivation by selective breeding. May not breed true from seed.

a waxy, waterproof material forming the external layer of the epidermal cells.

laying on the ground, but with the apex or tip turning upwards.

repeatedly dividing into two branches.

the passage of molecules of a substance in solution from a liquid where they are in high concentration to one where they are in low concentration.

secretions which act to break down prey so that the organism, plant or animal, can use it for nourishment.

a plant that has either male or female flower, but not both (example: a Nepenthes)

shoot which in some seedling Droseras is sent down into the soil from near the base of the stem, the growing tip then forming a tuber at a suitable depth.

an interacting community of organisms and their physical environment that is self-sustaining.

leaves that are sword-shaped and are not hollow.

substances produced by and found in living cells. They are also found in digestive juices of animals and carnivorous plants, each having power to break down specific substances.

living cells which form the thing surface layer, usually one cell thick, on leaves and young shoots.

plants that grow on other plants using them for support. Many orchids and Nepenthes are epiphytes.

protruding beyond an enclosing structure. In some flowers the palate extends beyond the petals.

a mass of cells and fluid secreted out of vessels or glands. In the carnivorous plant world, this often refers to the white globules found on the underside of the hoods of Nepenthes lowii and N. ephippiata.

exudate on Nepenthes lowii

a collective term for animals inhabiting one place.

transparent or translucent areas in the hood of Sarracenia and Darlingtonia plants. Areolae is a term that is also used for this feature.

Windows on Darlingtonia hood

Windows of Sarracenia minor

when all the roots arise from the same area and are about the same thickness and length.

thread-like; stalk of a stamen.

leaves whose shape is thread-like.

Drosera filiformis full sundew

curves alternately in opposite directions, zig-zags.

a plant displaying an inherited characteristic differing from the typical species or variety. However, it is not sufficiently stable or marked to justify the rank of variety.

water with very few dissolved minerals.

a kingdom of mostly microscopic organisms that are closely related to animals. They include spore producing organisms such as mushrooms, yeast and molds and play a vital roll in nutrient recycling within an ecosystem through their decomposition of organic matter.


a sex cell, contains half of the chromosome number of the organism. Two gametes combine to form a diploid cell.

the portion of the life cycle of a plant in which gametes are produced.

(plural: gemmae) a small body produced by the parent plant by non-sexual means which, when detached, may form a new individual.

Drosera scorpioides gemma

the collection of genes responsible for the various genetic traits of a given organism. Genotype refers specifically to the genes, not the traits; that is, the raw information in an organism’s DNA.

(plural: genera) a category of closely related species; the generic name is given as the first of the two names of each species. Some genera consist of only one species.

swollen or distended on one side.

a structure of one or many cells which secretes a substance.sundew gland

(plural: greges or grexes), derived from the Latin noun grex, gregis meaning ‘flock’, has been expanded in botanical nomenclature to describe hybrids based solely on their parentage. We use a common grex name like Sarracenia x moorei, when it shares the same parents as the other plants within that grex. In this example all offspring resulting from hybridizing S. flava and S. leucophylla are within the  S. x moorei grex.

the native environment in which an organism naturally lives.

plants that have different shaped and/or sized leaves at different times.

(plural: hibernacula) a winter resting bud formed when the main plant dies back, and from which the plant regenerates in suitable conditions. It is often rootless.

lid-like appendage hanging over or above the opening of many pitcher leaves.

Pitcher plant hood

the offspring resulting from a cross between two species or previously established hybrids.

(plural: hyphae) one filament of the vegetable body of a fungus.

flowers that have superior ovaries – the petals, sepals, and stamens are attached below the ovary.

said of the ovary when the sepals, petals and stamens appear to spring from the top of it.

flowering branch or flowering part of the plant above the stem-leaves. Includes branches, bracts and flowers.

Nepenthes inflorescene

that which is between two species (e.g. an interspecies cross resulting in a hybrid).

the leaves that form after the cotyledons appear. Juvenile leaves do not usually closely resemble the mature leaves.

the flat, widened portion of a leaf or petal.

immature insects in the ‘worm’ stage.

one which is narrow with near-parallel sides.

the main vein of a leaf running centrally and longitudinally through the blade. In the Dionaea (Venus flytrap) trap, both loves are attached to the midrib.

midrib of b-52 Venus flytrap

the form and structure of an organism.

a thick, sticky fluid, a gelatinous substance, or glue-like organic compounds of vegetable origin and complex structure.

butterwort mucilage used to capture preysundew gland

containing or pertaining to mucilage.

butterwort mucilage used to capture prey

an organism in which the characteristics have been changed by alteration of its hereditary material.

the mass of fine threads or hyphae which forms the vegetable body of fungus and which seeks and absorbs nutriment.

a mutually beneficial association between the root cells of a plant and the mycelium of a fungus. Often called a mycorrhizal association.

a sweet, sugary liquid produced by plants.

the place an organism occupies in an ecosystem.

container in which seeds are formed.

Sarracenia flower anatomy

a part of the ovary that will develop into a seed after fertilization.

a projection or platform-like structure on the lower lip of a sympetalous corolla.

the axis of an inflorescence from which secondary branches arise that bear flower, a branched raceme.

an organism which lives in or on another, obtaining nourishment from it without being of service to its host.

a stalk which is the last branch of an inflorescence, bearing the flower or fruit.

the major flower stalk which bears a cluster of flowers, or a flower stalk which bears a single flower.

a leaf or other flattened structure in which the stalk is attached to the undersurface. Shield or umbrella shape supported by a stalk attached near the center of the lower surface.

a plant that lives for more than two growing seasons.

the calyx and corolla of a flower or tepals.

in Nepenthes, a plate inserted on the rim of the mouth in most species. It is down-curved on both sides, and thus semi-cylindrical in section, and ribbed, the ribs being usually sharply toothed on the inner margin.

Nepenthes peristome

a two-lipped corolla with an arched upper lip and the protrusion of the lower lip into the throat area that almost closes the throat.

the leaf-like structure inside the sepals that is often colored.

Sarracenia flower anatomy

the slender stem that supports a blade of foliage, the leaf stalk.

a logarithmic index for the concentration of hydrogen ions in a solution. A reading below pH 7.0 indicates acidity, one above pH 7.0 indicate alkalinity.

pH Scale

observable characteristics, such as height, biomass, leaf shape and so on. We use the term phenotype in a more specific context to describe the collective expression of the genotype in conjunction with the environment on a plant’s observable characteristics.

the length of the daylight period.

the synthesis by plants of carbohydrates and more complex substances from carbon dioxide and water using the energy from light through the agency of chlorophyll.

(plural: phyllodia) leaf-like structures. In Sarracenia these are the pre-dormancy widened petioles.

dormant Sarracenia phylodia

the female part of a flower comprising the ovary, style and stigma.

Sarracenia flower anatomy

leaves of Cephalotus, Nepenthes, Darlingtonia, Sarracenia, and Heliamphora. Typical leaves are ascidiform; that is, tubular or hollow. Ensiform leaves tend to be sword-shaped and are not ascidiform.

Cephalotus follicularis

Colorful nepenthes

Darlingtonia Californica

Sarracenia Leah WilkersonHeliamphora

the male gametophytes that give rise to sex cells. They are produced in the anther of a flower.

lying flat on the ground.

(singular: protozoan) single-celled microscopic animals found in great numbers in both salt and fresh water, and in deep soil.

covered with hairs.

the resting stage of the larvae from which it will emerge as an adult.

an inflorescence consisting of a single main stem along which the flower are borne on pedicels.

turned backwards abruptly.

that which is rolled inwards.

root-like structure with the appearance and function of a root.

an underground root-like stem bearing scale-leaves and at least one bud.

Sarracenia division

an inaccurate term used in the past for rhizome.

a circular cluster of leaves.

forming or having this shape of a sac or pouch.

an organism which obtains its food from dead organic materials.

the transfer of pollen from the anther of a flower to the stigma of the same flower or other flowers on the same plant or clone.

a leaf greatly reduced in size and scale-like, usually sessile and seldom green.

a leafless flowering stem extending from a rosette of leaves or root itself to the flower or inflorescence.


one of the leaf-like or petal-like members which make up the calyx of the flower.

Sarracenia flower anatomy

attached without a stalk.

a group of mutually fertile and closely allied plants displaying differences from other related plants.

A group of organisms that interbreed and are reproductively isolated from others. It is designated by a binomial consisting of the genus and species name (example: Sarracenia leucophylla)

part of the flower which produces pollen, usually consisting of a filament which bears the anther.

Sarracenia flower anatomy

the end of the style to which pollen must be transferred in order to germinate and bring about fertilization.

Sarracenia flower anatomy

one of the two leaf-like appendages which are often present at the base of petiole.

in Utricularia this refers to the underground stems of terrestrial and epiphytic species.

the part of the pistil between the ovary and stigma.

Sarracenia flower anatomy

almost erect.

said of the ovary when it is placed above the level of the sepals, petals and stamens in the structure of the flower (opposite of inferior).

an internal link between two organisms which is to their mutual advantage.

flowers having petals which are partly to completely fused.

stalked glands which produce mucilage and other secretions, and which help trap prey.

sundew gland

segments of the perianth that have not differentiated into distinct sepals or petals.

spike-like structures which must be stimulated in order to induce the trapping action in Aldrovanda, Dionaea, Polypompholyx, and Utricularia.

a swollen underground stem, or occasionally a root, used to store food material.

the hibernaculum or winter resting bud containing food, formed by many water plants including some of the aquatic Utricularias.

a large number of individuals which differ from others in that species and breed true from seed.

in Utricularia a thin membrane which helps to seal the door by filling the chink below the lower edge of door and threshold.

the veins of an organ as a whole or their arrangement.

unequal selling.

the manner in which the leaf is packed in the bud.

when seeds or embryos begin to develop before they detach from their parent or fruit, this is considered a vivipary. In Venus flytraps, entirely new plantlets will sometimes sprout directly on the flower stalks – a false vivipary.

venus flytrap false vivipary

a group in which identical organs (like leaves) are arranged around the stem in a circle.

bilateral symmetry.