Glossary of Terms
Cacti-Related Terms and Definitions
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This glossary of cacti-related terms was put together by CactiGuide.com forum
moderator, John Chippindale of Leeds England.
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| Abaxial |
Turned away from axis; referring to surface of an organ, such as a leaf, facing away from the main stem (opp. Adaxial). |
| Acauline |
Stemless; sometimes only appearing to be without a stem where this is hidden below soil level. |
| Acicular |
Shaped like a needle, Cactus spines are often Acicular |
| Acropetal |
In the direction of the apex, referring to developmental sequence. |
| Acrotonous |
Emphasised towards the apex. |
| Actinomorphic |
Radially symmetrical; referring to a flower with more than two planes of symmetry (see Zygomorphic) |
| Acuminate |
Tapering to a point. |
| Acute |
Pointed. |
| Adaxial |
Towards the axis; referring to the surface of an organ facing towards the main stem (opp. Abaxial). |
| Adventitious |
Said of the roots which do not arise from the radicle or primary root system, but from elsewhere |
| Adventitious buds |
Buds appearing in an unusual place; for example, buds on leaves (Example: Kalanchoe ), or buds arising from the vascular bundles not, as we might expect, from the areoles, generally in response to an injury |
| Aerial root |
Root arising above the ground. |
| Alternate |
Of leaves or other parts not opposite or whorled but placed singly at different heights on the stem. |
| Anastomosing |
Connecting to form a network, especially veins in a leaf. |
| Anatrapous |
Inverted, recurved through 180; said of an ovule bent over against its own stalk, with the mouth or micropyle close to the placenta. |
| Annulate |
Ringed or banded. |
| Annulus |
The raised ring around the centre of a succulent flower. |
| Anther |
Male part of the flower that produces pollen, usually borne on a filament. Anther and filament together are known as a stamen. |
| Anthesis |
The period of time in which a flower is open. |
| Anthocyanin |
Blue, violet or purple pigment colouring leaves etc. |
| Anticlinal |
Said of the cell-walls which cut the surface at right angles (opp Periclinal). |
| Apex |
Tip, the highest point. |
| Apical |
Located at or constituting the apex. |
| Appressed |
Lying flat pressed closely against the surface. |
| Areole |
Highly condensed and modified short-shoot growing in the leaf axil as a felted cushion, unique to cacti, usually hairy and/or spiny; from them the flowers and offsets arise. |
| Aril |
Outer covering or merely an appendage of a seed formed from the funicle; may be pulpy or hard. |
| Ascending |
Nearly erect. |
| Autogamy |
Self-fertilisation or self-pollination. |
| Axil |
Notch or angle between the axis and any organ, e.g. leaf, arising from it. |
| Betalain |
Nitrogen-containing pigment found only in the group of families, including Cactaceae known as Centrospermae. |
| Binomial nomenclature |
In biology the binomial nomenclature is a standard convention that identifies each species by a scientific name of two words, Latin in form and usually derived from Greek or Latin roots. The scientific name of a species is formed by the combination of two terms The first name (capitalized) is the genus of the organism, the second (not capitalized) is its species. The scientific name of the Yellow alicoche hedgehog cactus is Echinocereus papillosus, while the Claret-Cup Hedgehog cactus is Echinocereus triglochidiatus. The first name applies to all species of the genus, Echinocereus is the name of all hedgehog cacti, but the entire binomial applies only to a single species. Many scientific names describe some characteristic of the organism (as: papillosus = with papillae; triglochidiatus = with three bristles); many are derived from the name of the discoverer or the geographic location of the organism. Genus and species names are always italicised when printed; the names of other taxa (families, etc.) are not. The genus name can be abbreviated to its initial letter (as E. triglochidiatus) when repeated or when several species from the same genus are being listed or discussed in the same paper or report. Subspecies are indicated by a trinomial; The advantages of scientific over common names are that they are accepted by speakers of all languages, that each name applies only to one species, and that each species has only one name. |
| Bleeding |
When sap or latex flows freely from a damaged stem. |
| Bloom |
1. A flower. 2. A waxy white or bluish-white coating on stems, succulent leaves or fleshy fruit. |
| Bract |
A modified leaf at the base of a flower or flower cluster, which often protects the flower. Bracts can resemble normal leaves, be small and scale-like or large and brightly coloured and look like petals. |
| Bristle |
A stiffened hair. |
| Cactophile |
Person who likes cacti. |
| Caducous |
Falling off early. |
| Caespitose |
Offsetting to produce many stemmed cushions or mounds. |
| Calcareous |
Of or containing lime or chalk. |
| Callus |
The protective tissue formed over a wound, for example, at the base of cuttings. |
| Calyx |
The ring of sepals that surrounds the petals of a flower before it opens. |
| Cambium |
Layer of tissue that gives rise to secondary growth in stems and roots by cell division. |
| Campanulate |
Bell-shaped. |
| Campylotropous |
Said of an ovule curved back on itself so that the micropyle is near to the hilum, as in Cactaceae. |
| Capsule |
A dry seed pod that splits open when ripe to release the seeds. |
| Carpel |
Female reproductive structure of flower, usually comprising ovary, style and stigma; carpels may be solitary or grouped or fused with others, as in Cactaceae (see Gynoecium). |
| Caudex |
The swollen water-storage tissue, usually composed of both root and stem, of a succulent woody plant. |
| Caudiciform |
1. Possessing a caudex. 2. With a swollen stem. |
| Central spines |
Those arising from the centre of the areole. |
| Centrifugal |
Tending outwards from the centre or axis. |
| Centripetal |
Tending inwards to the centre or axis. |
| Cephalium |
Modified flowering zone of some cactus stems, often marked by copious development of hairs and/or bristles. A distinction is sometimes made between the true "cephalium" of Melocactus, for example, where vegetative growth ceases when the cephalium forms and various kinds of "pseudocephalium," where vegetative growth can continue. |
| Chalaza |
Basal zone of ovule where nucellus and integuments join. |
| Chasmogamy |
(Chasmogamus) Production of flowers which open in the normal way to expose the reproductive organs. (The production of flowers which do not open is called cleistogamy) |
| Chimera |
(pl. chimaera) A plant that contains a mixture of tissues from two or more genetically different cells or tissues in the same part of a plant. These can be spontaneously mutated cells of the host organism or cells from a different organism or species produced as a result of organ transplant, grafting (Graft chimera), and artificial fusion of unlike tissues or genetic engineering. The name chimera derives from the Old French, from Latin "chimaera", from Greek "khimaira", which means chimera, she-goat. From Indo-European Root "ghei-" Chimera is a Greek mythological character a fire-breathing she-monster made up of the front parts of a lion, the middle parts of a goat, and the tail of a snake she is the daughter of Typhon. |
| Chlorophyll |
The green pigment present in leaves or stems and used in photosynthesis. |
| Chlorosis |
A more or less distinct lack of chlorophyll leading to the plant having a sickly yellow colour. Often a symptom of deficiency of a micro-nutrient such as iron or boron. |
| Ciliate |
Fringed with hairs. |
| Cladode |
A flattened stem that looks like a leaf. Particularly seen in Opuntia (pads). |
| Clavate |
Club-shaped. |
| Cleistogamous |
Is the condition of having perfect flowers which do not open and self-pollination occurs, flowers are fertile and produce a lot of seed. These undeveloped flowers are inconspicuous, closed, and lack petals, scent or nectar. They are always fertile while the more perfect flowers of the same plant are usually nearly or completely sterile. Practically all cleistogamous plants can also produce normal open (or chasmogamous) flowers. Cleistogamy appears to be related to environmental conditions: when the environment is harsh, plants are more likely to produce cleistogamous flowers (For example Frailea castanea) |
| Collenchyma |
Living tissue providing support and with characteristic unevenly thickened walls. |
| Connate |
Fused or grown together. |
| Cordate |
Heart-shaped. |
| Corking |
Gradual ripening of stem from the base, to produce a bark-like texture. |
| Corolla |
The collective name of the petals. |
| Corona |
The centre of the flower surrounding the stamens and style, the crown. |
| Cortex |
Layer of tissue between epidermis and vascular tissue, or external layer of such as bark or rind (adj. Cortical). |
| Cotyledon |
Embryonic leaf; first leaf or leaves of a seedling after germination. |
| Crenate |
With notched edges. |
| Crest |
Also called fasciation; a mutation that results when the growing point of a plant forms a long line, rather than a single point. In botanical terms it is usually signified by Cristate. |
| Cristate |
Crest-shaped or crested. |
| Cross-pollination |
See pollination. |
| Cultivar |
Assemblage of plants originated or selected and propagated artificially. |
| Cultivar (Cv.) |
(cultivar = cultivated variety) a form of a plant commercially or scientifically important derived from cultivation.
Cultivar names are given when the mutation occurs due to human influence. Examples: a mutation occurs in a greenhouse (or because of human involvement such as breeding, applying mutagens, propagation, or by cultural practices) The abreviation cv. is used to signify that the mutation is a cultivar. cv. is placed after the specific epithet and is not underlined or italicised.
Example: Astrophytum asterias cv. Onzuka or single quotes of cv. Astrophytum asterias 'Onzuka'
How to write:
1. The cultivar name is written after cv. or within the single quotes ( '....' ).
2. Capitalize the cultivar name.
3. Never underline or italicise the cultivar name.
Example: Astrophytum asterias cv. Onzuka or Astrophytum asterias 'Onzuka' Where a species' variation is great or strongly different from the normal and sufficiently mutated it is called a 'sport'. |
| Cupules |
Cup-shaped structure. |
| Cuticle |
Thin, waterproof layer that cover the epidermis. |
| Cutin |
Waxy, water-repellent substance impregnating cell walls. |
| Cutting |
A cut or detached section of a plant, either from a leaf or stem, or an entire leaf that is used for propagation. |
| Cyathium |
(plural Cyathia). Specialised inflorescence found in Euphorbia species, where several male flowers are reduced to a single stamen and are found alongside a sing-ovary female flower. The male and female flowers together are presented with often colourful bracts and/or glandular nectarines. |
| Cymose |
In the form of a cyme, a type of inflorescence in which the relative main axis is soon terminated with a flower and subsequent growth occurs from one or several side branches. |
| Damping off |
The speedy wilting and collapse of seedlings due to fungal attack on the seeding stem at soil level. |
| Deciduous |
Shed periodically, or annually |
| Decumbent |
Lying or growing along the ground but turning upwards at or near the apex. |
| Decurrent |
Running downward. |
| Deflexed |
Bent away, usually applied to the shape of a spine. |
| Dehiscent |
Splitting or bursting open. |
| Deliquescent |
Becoming liquid. |
| Deltoid |
Shaped like the Greek letter D (Delta). |
| Dentate |
Toothed. |
| Diaphragm |
Membranous protrusion in floral tube of some cacti which more or less closes the nectar chamber. |
| Dichotomous |
Forking equally; as when the stem divides into two equal branches. |
| Dieback |
The progressive death of a stem from the tip due to damage or disease. |
| Dimorphic |
Having two forms (opp. Monomorphic). |
| Dioecious |
Species that have male and female plants, i.e. the flowers on a particular plant will have only male or female organs and plant of the opposite sex is required in order to produce seed. |
| Distichous |
Arrangements of branches or leaves in two opposite rows. (For example: Haworthia truncata). |
| Diurnal |
Day flowering. |
| Division |
A method of propagation in which a single plant or a clump is divided into several sections, each with its own roots and a growing point. |
| Dormancy |
A temporary cessation of a plant's active growth and a slowing-down of its other functions, usually in winter, in drought or in extreme heat or cold. Some succulents can produce flowers when otherwise dormant. |
| Druse |
Mass of needle-like crystals contained in a cell. |
| Endemic |
Regularly or only found in a certain region or country. |
| Endosperm |
Nutritive tissue formed within the embryo sac. |
| Entire |
Smooth margins or edges. |
| Ephemeral |
Short lived. |
| Epicotyl |
Portion of the stem of an embryo plant or seedling lying above the cotyledons (see Hypocotyl). |
| Epicuticular |
"On the . . . Cuticle", especially epicuticular wax, a layer of wax (continuous, powdery [farinose], or variously structured into plates, coils etc.) cover the . . . Cuticle on the outer surface. |
| Epidermis |
Outermost cell layer. |
| Epiphyte |
Plant that grows on another plant without drawing nutrients from it (adj. Epiphytic). |
| Ericaceous |
Applied to acid compost with a pH of 6.5 or less. It is generally used form lime-hating plants. |
| Etiolation |
Pale, sickly, excessive growth caused by insufficient light, incorrect feeding, or overcrowding. |
| Etymology |
The etymology of a word refers to its origin and the historical roots of the term as a linguistic form. Etymology, in general, is the study of the origins and history of words. The roots of words.
The word etymology is derived from the Greek "etumos" which means real or true. The ending "ology" suggests the study/science of something, as in biology or geology. The Ancient Greek word "astron" means "star". And "phyton" means "plant". Hence Astrophytum literally means star plant. (See: Etymology of species names - Etymology of genus and variety names) |
| Excrescence |
Outgrowth, warty appendage, protuberance. |
| Exine |
Outermost layer of the pollen grain (see Intine). |
| Exotic |
Usually referring to tropical or sub-tropical plants. |
| Exserted |
Sticking out; said of stamens and/or style which extend beyond the perianth. |
| f. (fa.) Form (forma). |
Taxonomic rank below variety, used for a taxon that differs only in a single characteristic or in a group of closely interrelated characteristics. |
| Family |
A group of related genera. For example the family of Cactaceae contains about 140 genera. |
| Farinose |
Having a mealy appearance. |
| Fasciated |
Having abnormal growth with flattened and laterally expanded stems or irregular stems; caused by abnormal divisions of the growing point. |
| Fascile |
Bundle or cluster. |
| Fibrous root |
A fine, densely branching root, which absorbs moisture and nutrients from the soil. |
| Filament |
Stalk of stamen supporting anther. |
| Fissure |
The aperture between two otherwise united leaves. |
| Flat grafting |
See grafting. |
| Floccose |
Woolly, hairy |
| Flowerhead |
A mass of tiny flowers, or florets, that looks like a single large flower. |
| Forcing |
The technique of bringing a plant into growth or flower ahead of its natural season, usually by providing it with extra warmth or controlling the day length. |
| Form |
Cultivated or naturally occurring variant of a species, denoting a group of plants with several common characteristics. |
| forma |
(abbreviated f.)
From the Latin word "forma" meaning "form, shape" it is an infraspecific rank below variety, this is the smallest taxonomic category, generally used for sporadic or minor variations occurring among individuals of any population, mainly in horticultural applications. (E.g. spine length, flower or fruit colour, or habit response) The abbreviation f. is used to signify that the mutation is a form. forma (f.) is placed after the specific epithet and is not underlined or italicised. How to write the name of a botanical form:
1. The form name is written after (forma) f..
2. Do not capitalize the form name.
3. Underline or italicise the form name but not the form designation.
Example: Strombocactus disciformis f. cristata (Strombocactus disciformis forma cristata) |
| Funicle |
Stalk of the ovule attaching it to placenta. |
| Fusiform |
Spindle-shaped; elongated and terete, gradually tapering at each end. |
| Genus |
In the classification of living organisms the genus. (pl. genera) is a grouping of similar, closely related and morphologically similar Species. Similarly, genera are grouped into families, families into orders, orders into classes, and classes into phyla or divisions.
How to write:
1. The genus name is written first.
2. The genus name is always underlined or italicised.
3. The first letter of the genus name is always capitalized.
Example: Mammillaria or Mammillaria |
| Geophyte |
Herbaceous plant where the stem is wholly or partly below soil level, permanently of for short periods, for example, Pediocactus species that pull themselves into the soil outside the growing season to find protection from the elements, or caudiciform plants with swollen underground food-storage organs. |
| Glabrescent |
Becoming glabrous. |
| Glabrous |
Smooth, without hairs or excrescences. |
| Glaucous |
Possessing a smooth, blue-white, blue-green or blue-grey bloom. |
| Globose, globular |
Globe-shaped, spherical. |
| Glochids |
Barbed spines or hairs, mostly small and brittle; often in tufts, characteristic of the Opuntioideae. |
| Glutinous |
Sticky, glue like. |
| Graft chimera |
Graft chimaera (frequently called 'graft hybrids') are cellular hybrids between representatives of two or more named genera. They are a rare phenomenon arising exclusively in cultivation where two species, frequently of two distinct genera, are grafted together. The mingling of tissues belonging to the stock and scion through grafting in a nonsexual manner. The chimaera come up as a branch or shoot from the point of union which contains tissues of both species, resulting in an arrangement of both species being expressed in the shoot. Such shoots can be vegetatively propagated and cultivated. The formula for the graft-chimaeral nature of such a plants uses a " + " sign against the initial letter of the generic name and to connect the two "parent" species (not the multiplication sign " X " this show that they are not sexual hybrids). If intergeneric, graft-chimaeras can be given their own genus name (which is a combination of the two constituent generic names) preceded by a + sign. An example is: + Ortegopuntia (Ortegocactus macdougalii + Opuntia compressa). Graft chimaeras can be given cultivar names. The example above has been named +Ortegopuntia cv. Percy, They cannot be given species names. |
| Grafting |
A method of propagation in which an artificial union is made between two different parts of two closely related plants, a scion from one is grated on to a stock from another so that they grow into one plant. Methods include flat grafting, split grafting and side grafting. |
| Growing-point |
Group of cells capable of division at the tips of the growing shoots and roots, which produce new tissue. |
| Gynoecium |
The female organs of the flower, as a whole. |
| Habitat |
The natural home of a plant. |
| Hardy |
Able to withstand most climatic conditions all year without protection, often qualified with a minimum temperature, for example, -15c (5f). |
| Head |
A close-set group of flowers. |
| Herbaceous |
A non-woody plant in which the top growth dies down to a rootstock at the end of the growing season. |
| Hilum |
Scar left on the seed where the funicle was attached. |
| Humus |
Decomposed organic matter. |
| Hybrid |
A plant produced by crossing two different species within a genus or from two closely related genera (intergeneric hybrid). |
| Hybridization |
The production either in nature or in cultivation of a hybrid by cross-pollination (see pollination). |
| Hygrochastic |
Moving of plants parts caused by absorbing water or drying out. |
| Hypathodium |
Inflorescence consisting of a flattened disk-like or vessel-like structure into which individual flowers are sunk; typical of the genus Dorstenia. |
| Hypocotyl |
Portion of the seedling below the embryonic leaves or cotyledons (see Epicotyl). |
| Hypodermis |
Layer(s) of cells immediately under the epidermis. |
| Imbricate |
Overlapping. |
| Indehisent |
A fruit that remains closed at maturity. |
| Inferior |
Said of the ovary when positioned below the insertion of perianth and stamens. |
| Inflorescence |
Flower cluster or clusters. |
| Insertion |
Attachment, for example of stamens in a flower. |
| Integuments |
Outer and inner coats of the ovule. |
| Intercalary |
Inserted between already differentiated tissue regions. |
| Intergeneric hybrid |
See hybrid. |
| Internode |
That part of a stem which lies between two nodes. |
| Interstitial pits |
Depressions between (rather than within) testa cells. |
| Intine |
Inner layer of the pollen grain or spore (see Exine). |
| isodiametric |
Having the same diameter in all directions. |
| Joint |
A section of the stem. |
| Keel |
V-shaped ridge on one side formed by channel on the other surface. |
| Lanceolate |
Shaped like a lance. |
| Lateral |
A shoot or branch coming out of the main stem. |
| Latex |
The milky white sap that exudes or bleeds from damaged stems of some succulents, for example, Euphorbia. |
| Leaf bract |
See bract. |
| Leaf cutting |
A cutting composed of a single leaf. |
| Loam |
A medium soil with equal parts of sand, silt and clay, which is usually well-structured, fertile and moisture retentive but also free draining. |
| Mamilla |
Nipple-shaped tubercle or podarium with the areole at its tip. |
| Margin |
Edge of plant organ, such as a leaf. |
| Median |
Situated in the middle, lying in the axial plane. |
| Medulla |
Soft internal tissue, pith of stem or root (adj. Medullary). |
| Medullary rays |
Bands of parenchyma between pith and cortex. |
| Meristem |
Growth tissue; groups of cells capable of repeated division to form permanent tissue. |
| Micronutrients |
The nutrients required in small amounts, e.g. boron, copper, iron, magnesium manganese and zinc. Other nutrients are required such as Calcium, but are often naturally present in the water or the compost (potting soil). |
| Micropyle |
Opening in the integument of the ovule through which the pollen tubes enter. |
| Mitotic cell division |
Type of cell division where the chromosome set duplicates prior to division. |
| Monocarpic |
Flowering at the end of the natural life span, when the plant dies after the fruits have ripened, such as most species of Agave. |
| Monoecious |
Plants with flowers that have only male or female organs, but where both male and female flowers appear on the same plant. |
| Monomorphic |
Having a single shape or form (opp. Dimorphic). |
| Monopodial |
With single axis extending at the apex, producing successive lateral structures beneath it. |
| Monotype |
The only species within a genus. |
| Monstrose |
An abnormal, irregular stem growth. |
| Mucilaginous |
Slimy, or jelly-like. |
| Napiform |
Shaped like a turnip: Large and round at the top, tapering and very slender below. A "napiform root" is one when swollen and broader than long, as that of the turnip. The word napiform comes from the Latin word "napus" meaning "turnip", and the Latin word "forma" meaning "form, shape" |
| Naturalised |
Referring to plants thriving away from their natural habitat. |
| Nectary |
(extrafloral nectaries)
Extra floral nectaries are glands, usually located (in Cactus) in the tubercle-grooves or in the axils. These nectary-glands exude a viscous juice ( nectar) with a high sugar- content and represent a sophisticated strategy for ant attraction.
-The first hypothesis for why plants secrete extra floral nectar is that the presence of pugnacious ants seems to reduce the vulnerability of flower buds by herbivores insect, resulting in greater fruit production and tissue survival. (Or by decreasing seed predation on plants.)
-The second hypothesis is that they distract ants from foraging at floral nectaries, this might also serve as an adaptation to reduce ant visitation to flowers.
-The third hypothesis is the nutrient enhancement. Ant colonies tend to concentrate nutrients in the immediate vicinity of their nests -- through storing food, discarding debris, and defecating - plant that bearing extra floral nectar attract ant nests to their base.
-Moreover ants can play an important rule in distributing the seeds of this plant. In humid conditions, the nectar exudation (if not completely removed by ants) can cause the formation of mould which leads to ugly black-colouring of the epidermis. To prevent this, spray off the plant with water to remove the nectar. And provide very good ventilation.
(For example Coryphantha echinoidea) |
| Node |
Point on stem where a leaf or leaves arises. |
| Nomen Nudum |
Abbreviated n.n. A title lacking valid description. |
| Nucellus |
Central structure of ovule containing the embryo sac. |
| nutrients |
The chemical elements necessary for proper plant growth. Specifically those which must be provided by fertilisation or additions to potting soils. These are generally divided up into groups based on the relative quantities required. |
| Obconic |
Inverted cone-shaped. |
| Obovoid |
Inverted egg-shaped, narrower near point of attachment. |
| Obtuse |
Blunt, or partially rounded. |
| Offset |
Side-shoot, often easily detached for propagation; offsetting, sprouting. |
| Ontogenesis |
Development of an individual through its various stages. |
| Orthostichy |
Arrangements of nodes, areoles and so on in a vertical row (see Spirostichy). |
| Ovary |
The base of the female portion of a flower that develops into a fruit once fertilisation has occurred. |
| Ovate |
Broadly elliptic, egg shaped. |
| Ovoid |
Egg-shaped, broader near point of attachment. |
| Ovule |
Outgrowth of a seed plants ovary that develops into a seed after the egg cell it contains is fertilised. |
| Pan |
A shallow pot that is wider than it is deep, often used for potting established cacti and succulents. |
| Panicle |
Lax inflorescence or flower cluster. |
| Papilla |
(pl. papillae)
A small elongated or nipple-shaped protuberance on an organ from any plant surface. A rounded projection from a portion of an epidermal cell. |
| Papillose |
(Also: papillar; papillate; papillary) of a rough surface, covered with many tiny projections (papillae). |
| Parastichy |
Secondary spiral in phyllotaxis. |
| Parenchyma |
Basic living cell tissue. |
| Pathogen |
Any micro-organism which causes disease, especially bacteria, fungi and viruses. |
| Pectinate |
Comb-shaped |
| Pedicellate zone |
Portion of flower beneath ovary. |
| Peduncle |
Main stem of a whole inflorescence. |
| Pendent |
Hanging |
| Perennial plant |
A perennial plant or perennial (from the Latin "per" meaning "through", and "annus" meaning "year") is a plant that lives for more than two years. This term is usually applied to herbaceous non-woody plants plants or small shrubs rather than large shrubs or trees, but used strictly it also applies to the larger and longer-lived species. Perennials usually produce one or more flower crop each year. |
| Pericarp |
The pericarpel at the fruiting stage. |
| Pericarpel |
That part of the floral axis surrounding the ovary. |
| Periclinal |
Said of outer or tangential cell-walls (opp. Anticlinal). |
| Periderm |
Secondary protective tissue with cork cells. |
| Perinath |
Calyx (sepals) and corolla (petals), taken together, in Cactaceae, the sepals and petals form a intergrading series, termed perianth-segments, "tepals" or "sepaloids" and "petaloids". |
| Perisperm |
Nutritive tissue in the seed formed outside the embryo sac. |
| Petal |
Each of the segments of a corolla, usually coloured to attract pollinators. |
| Petaloid |
Petal-like. |
| pH |
The horticultural measure of the acidity or alkalinity of a soil or compost; pH7 is neutral, below pH7 is acid and above pH7 is alkaline. Most cacti prefer a slightly acid compost. |
| Photosynthesis |
The production by a plant of compounds required for its growth, promoted by light acting on the plant's chlorophyll. Also needed in the process are water and carbon dioxide. |
| Phyllotaxis |
Mode of arrangement of leaves in relation to axis. |
| Pinching out |
The removal of the growing point of a plant or its stems to induce the production of side shoots or more flower buds. |
| Pinnate |
Compound leaf with two or more pairs of leaflets. |
| Pistil |
Female organs of flower, usually consisting of stigma, style and ovary. |
| Placenta |
Part(s) of ovary which bear ovules. |
| Placentation |
Arrangement of ovules within the ovary. |
| Plantlet |
A new young plant, which usually arises from the site of a wounded stem or leaf or is naturally borne on the leaf margins, for example in some Kalanchoe. |
| Plumose |
Feathery, covered with fine hairs. |
| Podarium |
Nodal swelling. Corresponding to the leaf-base. |
| Pollen tube |
Tube formed by protrusion of Intine which penetrates style to convey pollen for fertilisation. |
| Pollination |
(also known as cross-pollination). The transfer of pollen from the anther to the stigma on the same or a different flower by gravity, wind, birds, bats or insects in nature, or by hand in cultivation. |
| Pollinium |
Waxy mass of pollen as found in the family Asclepiadaceae (and in orchids). |
| Polyhedral |
Many-faceted. |
| Porrect |
Sticking straight out forwards. |
| Primary root |
The first root which develops as a continuation of the radicle. |
| Primordium |
Rudimentary outgrowth consisting of tissue capable of giving rise to, for example, a leaf. |
| Procumbent |
Growing along the ground. |
| Proliferous |
Bearing offsets; also said of flowers or fruits which produce further flowers from receptacular areoles, thus sometimes forming strings of fruits. |
| Propagator |
A small case, usually heated with a removable top of plastic or glass. It is used to provide a suitable moisture retentive atmosphere for raising seedlings or rooting cuttings. |
| Prophyll |
Rudimentary leaf or bracteole at base of leafy shoot. |
| Prostrate |
Low growing. |
| Pruinose |
Frosted appearance with white powdery coating. |
| Pseudanthium |
Reduced inflorescence which as whole appears to be a single flower, for example, the flower heads of the family Compositae or the cyathia in species of Euphorbia. |
| Pseudocephalium |
An apparent cephalium of wool and/or bristles (see Cephalium). |
| Pubescent |
Covered with fine, minute hairs. |
| Pulp |
Juice or flesh which fills cavity of fruit. |
| Pulverulent |
Covered in powder. |
| Raceme |
Inflorescence where the main flower stalk does not end in a truly terminal flower and where the flowers start to open from the bottom to the top of the stalk. May be branched or unbranched. |
| Radial spines |
The spines arranged around the edge of the areole |
| Radicle |
Embryonic root. |
| Ramifying |
Branching. |
| Raphe |
Strand or ridge of vascular tissue in ovule connecting base of nucellus with the placenta. |
| Receptacle-tube |
Elongate-tubular part of the floral axis situated above the ovary, supporting the floral organs; sometimes taken to include the pericarpel. |
| Recurved |
Curved backwards. |
| Reflexed |
Curved downwards. |
| Resting period |
The period of dormancy in a plant. |
| Reticulate |
Net-like or criss crossing. |
| Rhizome |
Somewhat thickened, fleshy stem rooting at the nodes while continuing to grow at the tip, producing new leaves. |
| Rib |
A ridge on a cactus stem, usually vertical, that is formed from the skin. |
| Root ball |
The root mass, together with its soil or compost, visible when a plant is lifted from its bed or taken from its pot. |
| Root crown |
The point at which the root and stem of a plant meet and the primary vascular anatomy changes from that of a stem to that of a root. Transition point between stem and root. It may be clearly or vaguely apparent |
| Rootstock |
1. A vigorous plant which provides the root system in grafting. Also know as a stock.
2. A plant's root system. |
| Rosette |
A group of leaves radiating from approximately the same point, often borne at ground level at the base of a very short stem, or at the tip of longer stems. |
| Rostrate |
With a beak-like projection (noun: Rostrum). |
| Rosulate |
Arranged in the form of a rosette. |
| Rotate |
Wheel-shaped; said of a flower in which the petals or perianth-segments radiate horizontally, like the spokes of a wheel. |
| Rugose |
Wrinkled. |
| S.p.n. |
Species nova: newly discovered. |
| Saxicolous |
Refers to plants growing on rocks. |
| Scales |
Thin, leaf-like structures. |
| Scientific name |
How to Write a Scientific Name |
| Scion |
A shoot or bud of one species which is united to the stock of another plant by grafting, for propagation. |
| Sepals |
Leaf-like structures surrounding and protecting the petals of a flower. Collective know as the calyx. |
| Serial |
Said of buds that arise sequentially. |
| Serrate |
Saw-edged. |
| Sessile |
Stalkless. |
| Shrub |
Plant usually branching from the base rather than with a single stem or trunk and branching higher up (see Tree). |
| Side grafting |
See grafting. |
| Simple |
Solitary. |
| Sinuate |
Wavy-edged. |
| Spathulate |
Spatula shaped, I.e. tapering from a rounded apex into a gradually narrowing stalk. |
| Species |
In the classification of living organisms the species, is the fundamental unit of classification, consists of populations of related individuals that resemble one another, that are able to breed among themselves, but are not able to breed with members of another species. Populations within a species that show recognizable, inherited differences but are capable of interbreeding freely are called subspecies, races, or varieties. How to write specific Epithet:
1. The specific epithet is written second.
2. The specific epithet is always underlined or italicised.
3. The first letter of the specific epithet name is never capitalized.
|
| Spination |
Spine characteristics and distribution. |
| Spines |
Sharp-pointed, hard or woody structures, derived, in cacti, from leaves. |
| Spirostichy |
Arrangement of nodes, areoles and so forth in spiral rows (see Orthostichy). |
| Split grafting |
See grafting. |
| Ssp. |
Sub-species; plants with similarities but differing in certain features. |
| Stamen |
Pollen-bearing male organ of flower, consisting of anther and filament. |
| Staminode |
A sterile, usually reduced stamen. |
| Standard |
A tree-like cactus obtained by grafting a trailing or arching species, for example Schlumbergera, ot to a tall or columnar species. |
| Stapeliad |
Common name used for members of the Asclepiadaceae |
| Stem cutting |
A cutting taken from a portion of stem. |
| Stem succulent |
Plant with succulent stems, without proper foliage leaves (e.g.: cactus) |
| Stigma |
Surface or structure at apex of style, receptive to pollen. |
| Stock |
See rootstock. |
| Stolon |
Sucker or runner; a prostrate basal branch, above or below ground, which can root and produce new stems or plantlets. |
| Stoloniferous |
Producing stolons. |
| Stoma |
Minute pore in epidermis through which gaseous exchange occurs (plural Stomata). |
| Striate |
Marked with lines on the surface, sometimes with slight ridge or furrow. |
| Strophiole |
Swollen excrescence or appendage of the hilum of a seed. |
| Style |
Structure, usually slender, connecting ovary and stigma(s). |
| Sub-genus |
A division of a genus. |
| Suborbicular |
Almost disc shaped; flat, with a circular outline. |
| Subsp. |
Subspecies. Taxonomic rank below species and above variety and form. There is no absolute definition for the term, which in recent years has been used as a synonym for and in preference to "variety." |
| Subtending |
Said of a leaf in whose axil there is a bud, areole and son on. |
| Subulate |
Awl-shaped, slende3r and tapering. |
| Succulence |
Juiciness, fleshiness. |
| Succulent |
Juicy, fleshy, water-retaining; succulent plants store water in specific organs, for example, stem-succulents, leaf-succulents. |
| Superior |
Said of the ovary when the perianth and stamens are inserted below it on the receptacle. |
| Synonym |
Title already known under a different name. |
| Tap root |
The principal swollen, downward growing root of a plant. |
| Taxon |
Taonomic group, e.g. genus. |
| Taxonomy |
The principles and practice of classification. |
| Tendril |
Slender modified branch or leaf that is sensitive to touch and coils to help a plant climb or anchor itself. |
| Terete |
Rod-like, rounded and smooth, often tapering. |
| Terminal |
At the tip of a stem or branch, usually applied to a bud, rosette or flower. |
| Tessellate |
Patterned like a mosaic or pavement. |
| Testa |
Seed coat. |
| Throat |
Of a flower; the visible portion between limb and tube. |
| Top-dressing |
An inert material such as stone or grit, usually decorative, that is applied to the surface of the soil or compost around the plant to aid drainage and to decrease soil erosion or moisture loss. |
| Transverse |
Across; at right angles to the vertical. |
| Tree |
Plant with usually single, distinct trunk between ground and first branching. |
| Tribe |
Group ranking between genus and subfamily. |
| Truncate |
Ending abruptly as if cut off. |
| Tube |
The tubular section of the flower above the ovary, bearing the petals, etc. |
| Tuber |
Swollen underground stem with storage capacity. |
| Tubercle |
Small, rounded prominence (adj. Tuberculate). |
| Tuberous root |
Swollen root with storage capacity. |
| Turbinate |
Shaped like a top or an inverted cone. |
| Type |
The principal example of a genus or species. |
| Umbilicus |
Navel-like formation; depression (adj. Umbilicate). |
| Undulate |
Having wavy edges. |
| Variegation |
A naturally occurring or viral induced mutation, which appears as stripes or whole sections of tissue that are without chlorophyll. Variegated varieties are often prized for the attractiveness of the markings caused by the mutation. |
| Variety |
A plants variety is a divergence in growth from the usual or normal of one or a few of the characteristics of the species, this different growth is inheritable by succeeding direct generations. Variety names are given when the mutation occurs in nature. The abbreviation var. is used to signify that the mutation is a variety. var. is placed after the specific epithet and is not underlined or italicised.
How to write:
1. The variety name is written after var.
2. Capitalize the first letter of the variety name only if it is a proper noun.
3. Underline or italicise the variety name.
Example: Mammillaria lasciacantha var. egregia (Mammillaria lasciacantha var.egregia) |
| Vascular bundle |
Group of conducting channels and associated tissues. |
| Vernalization |
A process of thermal induction in plants, in which growth and flowering are promoted by exposure to low temperatures |
| Verrucose |
Covered in wart-like excrescences. |
| Verticillate |
Arranged in whorls. |
| Viable |
Able to survive and develop. |
| viscid |
Sticky, glutinous. |
| Wart |
An irregular growth (see tubercle). |
| Whorl |
Cluster of three or more parts such as leaves radiating from single node. |
| Window |
A layer of semi-transparent cells, containing calcium oxalate, at the tip of a succulent leaf. The window protects the chlorophyll in the plant body from being destroyed by strong sunlight by diffusing the light before it reaches the chlorophyll, so enabling photosynthesis to take place. |
| Wool |
Dense covering of fine, soft hairs. |
| Xeric |
Having very little moisture; tolerating or adapted to dry conditions |
| Xerophyte |
Plant adapted to dry conditions. |
| Zygomorphic |
Bilaterally symmetrical; divisible in symmetrical halves in one plane only (see Actinomorphic). |
