Glossary

This page is not intended to define the many hundreds of scientific words used specifically in botany.  This is just a quick reference guide to words we have used in our posted content.  Listed alphabetically is a selection of uncommon words used on this website that you may not recognize.

Areole – The small bumps on a cactus from which clusters of spines grow.

Binomial Name – The binomial name of a plant is the genus followed by the species.  The genus name is capitalized and the species name is lower case.  Both names are italicized. (i.e. Kalanchoe tomentosa)  The binomial name is sometimes referred to as the scientific name or the botanical name.

Botanical Nomenclature – This is the scientific naming of plants.  The phrase ‘botanical nomenclature’ specifically refers to just the naming of the plants and not the grouping or classifying aspects which would fall under the broader designation ‘plant taxonomy’.  The official naming of plants falls under the governance of the International Code of Nomenclature for Algae, Fungi, and Plants.

Chlorosis – Chlorosis refers to the loss of the normal green color of plants.  Chlorosis is often caused by the lack of light or from iron deficient soils.

Cladode – A flat stem that may look like a leaf.  The pad of a prickly pear cactus and the stem segments of a Christmas Cactus are cladodes.

Cladophyll – A flat stem segment that resembles a leaf.

Crenate – Leaf having a scalloped or round toothed edge.

Cultivar – A cultivar is a ‘cultivated variety’ from within a species.  The plant was developed from human intervention but is not a cross between two species like a hybrid.  It may look different from varieties within the same species such as being larger, having different colored flowers, a different leaf shape and so on.  The name of a cultivar is shown in uppercase but not italicized and it will be surrounded by single quotes. (i.e. ‘Chocolate Soldier’) (See also “Hybrid” and “Variety”.)

Dentate – Having a serrated or tooth-like edge.

Epiphyte – A plant that grows on another plant but is not a parasite.  Most epiphytes grow on trees.

Etiolate, Etiolated, Etiolation – When a plant is not getting enough sunlight it will develop elongated weak stems or flattened curled down leaves.  It becomes deformed as it tries to reach out to find more sunlight.  Often the etiolated parts of the plant will turn a pale yellow color (chlorosis).

Farina – White powdery substance on the leaves of some succulents.  It is a beneficial substance that protects the plant from sunburn.

Friable – Soil that is easily crumbled between the fingers, reduced to powder.  Friable is considered a good quality for plant growing soil.

Glaucous – Botanically refers to a whitish, bluish or grayish waxy coating on a plant that may easily be rubbed off.  The beneficial glaucous substance on succulents helps prevent the plant from sunburn.  Alternately described as a range of pale colors that may be bluish-grey, bluish-green or grayish-green.

Hybrid – A hybrid is simply a man-made cross between two varieties, a variety and a cultivar, or two cultivars for example.  The name of a hybrid is shown in uppercase but not italicized and it will be surrounded by single quotes. (i.e. ‘Fang’) (See also “Cultivar” and “Variety”.)

Lanceolate – Shaped like the head of a spear or lance.  This word is used to describe a succulent leaf that has a narrow oval shape that tapers to a point at the tip end.

Lithophyte – A plant that grows on a stone or a bare rock.

Midrib – The large strong vein in the center of a leaf.

Monocarpic – Plants that may live for years but then after flowering and producing seed they die.  Monocarpic succulents only flower one time.

NPK – Sometimes shown as N-P-K it stands for the ratio of nitrogen (N), phosphorus (P) and potassium (K) that is contained in a soil or a fertilizer.  Commercial potting soils and fertilizers often simply list the nitrogen, phosphorus and potassium percentage in numbers such as 10-20-15.

Offset – An offset is a new growth identical to the parent plant that starts on the stem or root.  These are also called pups.  (See also “Sucker”)

Pendent, Pendulant – Overhanging, drooping or hanging down.

Phylloclade – A flat stem segment that looks like and functions much like a leaf.

Phytoremediation – The decontamination of the water, soil or air by the use of plants and trees.  It specifically refers to the ability of plants to remove toxic hazardous chemicals from the environment.

Plant Habit – This term refers to the general overall shape of the plant.  The plant habit may include things such as the stem length, width and development, the texture and the branching pattern.  Plant habit also points to any specialized system the species has to store water or carbohydrates.

Plant Taxonomy – This is the science of discovering, identifying, describing, classifying and naming of plants.

Pup – See “Offset”

Rosette – The leaves or other parts grow out from a circular arrangement and are of similar height.  The leaves radiate out from a single location on the stem.  Many succulents have a circular and symmetrical pattern from the base of the plant.

Runners – See “Stolon”

Rhizome – A root-like stem that usually grows horizontally underground.  The rhizome may eventually send out additional roots and shoots from its nodes.  Where it emerges from the soil it forms a genetically identical plant.  Rhizomes are sometimes simply referred to as underground stems.  A rhizome grows underground while a stolon grows above the surface.  Rhizomes are sometimes called rootstalks or creeping rootstalks.

Sport – A variant of a species that has occurred naturally.  A spontaneously mutated plant that differs in various ways from its parent plant.

Stolon – A stolon sprouts horizontally above ground from the stem and in some cases it will root and develop into a new identical plant.  The new plant may be referred to as the daughter plant.  A stolon grows above the surface while a rhizome grows underground.  Stolons are also sometimes referred to as runners.

Striated – the area is marked by a series of grooves, ridges or lines.

Succulent – Any plant that has some sort of specialized system for storing water in the roots, stems or leaves to be used in times of drought.  All cacti are succulents.  There are many succulents that are not cacti and they come in an almost endless variety of shapes, sizes and colors.

Sucker – A sucker is new growth identical to the parent plant that starts from the root and then develops into an aerial shoot.

Taproot – The primary descending root from a single plant.

Taxonomy – See “Plant Taxonomy”

Tuber – The end of an underground branch or stem that becomes swollen because it is storing food material.  They are usually oblong, spherical or oval in shape.

Variegated – Leaves or stems irregularly marked with spots or blotches of a different color.

Variety – This term may be used in the broad sense of “different kinds.”  When used in the technical botanical sense it refers to a plant that is a pure variation within a species.  In botanical terms a variety is synonymous with a species.  A variety occurs from nature and has not been developed through human manipulation.  The name of a variety is shown in uppercase but not italicized. (i.e.  Panda Plant) (See also “Cultivar” and “Hybrid”.)

Xeromorph – A plant that has structural adaptations to prevent water loss from evaporation.  It may have succulent leaves and be found in arid habitats but they are not always drought-tolerant.

Xerophyte – A plant such as a succulent that lives in arid habitats.  A xerophyte plant is able to tolerate drought for long periods of time.