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  • Glossary
| Last Updated:22/02/2024

GLOSSARY

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A
Abstric'tion

(ab, from, st rictus, drawn together), a term which covers both Abj unction and Abscission.

Aesthe'sia

(atadrjcns, perception by sense), Czapek’s expression to de¬note the capacity of an organ to respond to definite physical stimuli.

abtare'viated, abbrevia'tus,

shortened, as when one part is shorter than another; Abbreviation, a selection of those most frequently used will be found in the Appendix, aber'rant, aber'rans (aberro, I go astray), differing from usual struc¬ture, departing from the type. Aberration, non-typical structure, abiet'ic (Abies, a fir-tree), used of certain coniferous products which are not exclusively from Abies ; Anliy'dride, the resin in turpentine

alp'ine

properly denoting plants belonging to the Alps (alpes, mountains), but frequently" used in a wider sense, embracing alpestrine, as well as the higher situated plants, alsina'ceous (Alsine, Tourn. -f ceous), used of a petal having a short, but distinct claw, alternate, alter'nm ; alterna'tits, alter’nans, (1) placed on opposite sides of the stem on a different line ;(2) when between other bodies of the same or different whorls, as iri Umbelliferae, where the stamens are alternate with the petals, that is, between them ; alternipin'nate, or altern'ately-pin'nate, when the leaflets of a pinnate leaf are not exactly opposite each other : Alter-nation, Alterna'tio. the fact of being alternate, — of Generations, the reproduction by organisms which do not precisely resemble the parent, but the grand-parent, applied especially to the regular succession of sexual and asexual phases, as in Ferns, etc.; alternative, alttrnati'- vus, in aestivation when the peri¬anth segments are in two rows, and the inner so covered bv the outer, that each exterior member overlaps the half of two interior members.

arundina'ceous

reed-like, having a culm like tall grasses ; arundin'eous, reedy, abounding in reeds.

Acon'itin

Acon'itin, the alkaloid derived from monkshood, Aconitum Napellus, Linn.

Apex (pi. Apices).

The tip or distal end.

Anthesis.

Flowering; strictly, the time of expansion of a flower when pollination takes place, but often used to designate the flowering period; the act of flowering.

Anastomosing.

Netted; interveined; said of leaves marked by cross veins forming a network; sometimes the vein branches meeting only at the margin.

Ampulla.

A bladder, as in Utricularia.

Adventitious Buds.

Buds appearing on occasion, rather than resident in regular places and order, as those arising about wounds.

Acropetal.

Arising or developing in a longitudinal plane from a lower toward a more apical position, the opposite of basipetal.

Abrupt.

Changing suddenly rather than gradually, as a leaf that is narrowed quickly to a point, not tapering; also pinnate leaf that has no terminal leaflet.

Amphiploid (Amphidiploid).

A type of polyploid characterized by the addition of both sets of chromosomes from each of 2 species.

Anatropous.

Said of an ovule that is reversed, one whose opening (micropyle) is close to the point of funiculus attachment

acropetal

Produced, developing, or opening in succession from base to apex,

acaulescent

Without a stem, or apparently so.

acorn

The fruit of the genus Quercus (oak) in the Fagaceae.

acicle

A stiff bristle or slender prickle, sometimes with a gland at its apex.

acidophile

A plant that thrives in an acid soil.

abortive

Imperfectly developed

accrescent

accrescent Increasing in size with age, as the calyx of some plants after flowering, e.g. Physalis alkekengi (Chinese Lantern).

acanthophyll

A spine, often large, derived from a leaflet

abscission

layer A layer of cells that develops across the base of a petiole or pedicel and then weakens, causing the leaf or flower to fall off.

abscission

The shedding of parts of a plant, e.g. leaves, flowers, etc. by means of an abscission layer, either naturally from old age or prematurely from stress.

actinomorphic (regular, radially symmetric)

Divisible through the centre of the flower in several or many longitudinal planes, the halves of the flower being mirror images in every case.

acrogenous

Growing only at the apex of the stem,

aerial root

An adventitious root that does not grow down into the soil, e.g. the roots of epiphytic orchids that absorb water from the surrounding air

aerenchyma

Tissue with well-developed air spaces between the cells, characteristic of the roots and stems of water plants

adventive

Growing spontaneously in a particular region but not native there,

adventitious root

A root that arises from any part of a plant other than the primary root system.

acyclic

Arranged spirally rather than in whorls

aculeate

Bearing prickles.

acrotonic

A type of branching in which the shoots nearest the apex of the stem show the greatest development,

acrostichoid

Resembling Acrostichum, one of several genera of ferns in which the sporangia are distributed over the lower surface of the fertile lamina.

anterior

Front, away from the axis

anemophilous

Depending on the wind to convey pollen for fertilisation

androgynophore

A stalk bearing both androecium and gynoecium, as in the flowers of many members of the Passifloraceae.

antenna

One of the pair of slender structures on the pollinarium of the genus Catasetum that, when touched by an insect, cause the pollinia to be forcibly ejected

annual

ring A growth ring, formed in the course of a year in the stem or root of a woody plant, that consists of a band of large xylem cells produced in the spring (see spring wood), followed by progressively smaller cells produced in the late summer and autumn (see autumn wood).

aggregate species (collective species)

A group of two or more closely related species which for convenience have been given a shared name, e.g. Rubus fruticosus (blackberry),

anemophily

Pollination by means of the wind.

anemochore

A plant whose seeds or fruits are dispersed by the wind,

androecium

The male sex organs (stamens) collectively.

ament (amentum, catkin)

A spicate, oftenpendulous inflorescence of unisexual, apetalous flowers

allopatric

Of plant species or population snot growing in the same geographical area,

aestival

Occurring in early summer,

annulus

The specialised ring of cells on asporangium which is involved in the release of the spores

angustiseptate

Having the partition (septum) across the narrowest diameter of the fruit, as in Capsella bursa-pastoris (Shepherd's Purse).

ancipitous

Having two edges and being flattened, as the pseudobulbs of Laelia rubescens.

amyloplast

A form of leucoplast occurring in storage organs that can convert sugar into starch,

allele

, allelomorph Any one of the alternative forms of a particular gene,

agg. (aggregatum)

Aggregate, added to the name of a species to signify the inclusion of other taxa in a closely related group,

amphiphloic siphonostele

(solenostele) A type of stele in which a central core of pith is surrounded first by a ring of phloem, then by a ring of xylem, followed by a second ring of phloem.

alar

flower A flower borne in the fork between the two branches of a dichasium, e.g. as in some genera of the Caryophyllaceae.

arilloid

Resembling an aril,

adventitious bud

A bud that arises from any part of a plant other than the axil of a leaf,

adherent

In close contact with a different part, but not fused with it.

adaxial

The side of an organ towards the axis, ventral.

acuminate

Narrowing gradually to a point.

abaxial

The side of an organ away from the axis, dorsal

aristate

With an arista

adnate

United with a different part, as stipules to a petiole [92], or a bract to a peduncle.

acute

Sharply pointed.

actinostele

A type of protostele, in which the xylem forms a star-shaped structure with phloem between its rays.

aroid

A member of the Araceae, as Arum maculatum (Lords-and-Ladies).

arillate

With an aril.

articulate

, articulated Jointed

archegonium

The female sex organ in ferns that produces the egg

arboreous, arborescent

Tree-like in growth or general appearance,

acrospire

The first sprout of a germinating seed,

arachnoid hairs

Fine, interlaced hairs resembling a spider's web, like those on the leaves of Sempervivum arachnoideum

annular

Ring-like.

anemochory

The dispersal of seeds or fruits by the wind.

andromonoecious

Having male and bisexual flowers on the same plant,

amplexicaul

Clasping the stem, but not completely encircling it.

annulate

Composed of rings or having that appearance

anthela

The panicle in some species of Juncus (rush), in which the upper branches are overtopped by the lower ones

anisophyllous

With two leaves of a pair differing in shape or size,

anatropous

With the body of the ovule inverted so that it lies alongside the funicle.

anastomosing

Having the veins branched, the vein branches sometimes meeting only at or near the margin of the leaf.

annual

A plant that completes its life cycle within a single year.

anastomosis

A cross-connection of veins in a leaf, producing a somewhat denser network of veins towards the margin

amphidiploid

An allopolyploid containing a diploid set of chromosomes from each of two different species.

albuminous

Possessing albumen,

alate

(winged) Having a wing or wings.

anisophylly

The condition of being anisophyllous.

anatomy

The science or study of the structure of plants, based on dissection

Angiospermae (Anthophyta, Magnoliophyta)

The angiosperms, flowering plants whose ovules are enclosed in an ovary

anemochorous

Of seeds or fruits, dispersed by the wind.

androphore

A stalk bearing the androecium, as in the flowers of some members of the Tiliaceae.

androdioecious

A species in which individual plants bear only male flowers or only bisexual flowers

alternation of generations

In the life cycle of ferns and fern allies, the alternation of a haploid gametophyte generation, reproducing sexually, with a diploid sporophyte generation, reproducing asexually.

allogamy

(cross-fertilisation) Fertilisation of the ovules of a flower by pollen from a different flower,

achene

A small, dry, one-seeded, indehiscent fruit, strictly of one carpel, as in the genera Ranunculus and Rosa

accumbent

accumbent Of cotyledons, having the edges adjacent to the radicle.

acidophilic, acidophilous

Adapted to or thriving in an acid soil.

abortion

Non-formation or incompletion of a part.

acrogen

A flowerless plant, e.g. a fern, in which growth occurs only at the apex of the stem,

achlamydeous

Without a perianth, as the flowers of Salix (willow).

aggregate fruit

A fruit formed by the joining of several carpels that were separate in the flower, as in the genus Rubus (Rosaceae).

agamospermy (seed apomixis)

A form of apomixis in which seed is set, but without sexual fusion. Offspring produced in this way have the genetic constitution of the parent plant. Genera in which this process occurs include Taraxacum (dandelion), Hieracium (hawkweed), and Rubus (blackberry, etc.).

aff. (affinis)

Having affinity with, near to. Usually precedes the name of a species to indicate a plant not conforming exactly with the description of that species but clearly related to it.

aerotropic

Turning towards or away from the source of oxygen

apospory

The development of a gametophyte from a sporophyte without the production of spores.

apex (plural apices)

The tip of an organ.

antheridium

The male sex organ in ferns that produces antherozoids

anther

The part of the stamen that produces pollen.

antisepalous

Of stamens, situated on the same radii as the calyx segments, as distinct from alternating with them.

anthesis (efflorescence)

Flowering time

aposepalous (chorisepalous, dialysepalous,polysepalous)

With a calyx of separate sepals, as Geranium

apophysis

The part of a cone-scale that remains exposed when the cone is closed

apocarpous (dialycarpic)

Having free carpels.

apiculate

With an apiculus

apomixis

Reproduction without fertilisation, either vegetatively

apocarpy

The condition of being apocarpous.

apiculus

A short sharp point

antipetalous

Of stamens, situated on the same radii as the corolla segments, as distinct from alternating with them.

aquatic

Living in water or a waterlogged environment

appressed (adpressed)

Lying flat against

asymmetric

With one side of the leaf larger then the other

apetalous

Without petals

antrorse

Pointing forwards or upwards

anthocyanins

The pigments present in solution in the vacuoles of plant cells that are responsible for the red, blue, or purple colouring in flowers, fruits, and other parts of flowering plants

aperture

aperture An opening, often circular

aperturate

Having pores

aseptate

Without partitions,

arista

An awn or stiff bristle

apomictic

Reproducing either by seeds produced asexually, as many species of Taraxacum (dandelion) and Hieracium (hawkweed), or vegetatively, as when a part of a plant may become detached and develop into a separate plant without any sexual reproduction having taken place.

apical placentation (pendulous placentation)

Thearrangement in which the placenta is situated at the top of the ovary and the ovule or ovules hang down from it.

antipodal

cell One of the group of usually three cells, typically haploid, that lie in the embryo sac at the opposite end to the micropyle

anthocarp

A structure comprising a fruit enclosed in a persistent perianth, as in the Nyctaginaceae

antherozoid (spermatozoid)

A male sex cell with sets of flagella that enable it to move in water.

asexual

Not sexual, i.e. not involving the fusion of male and female cells

apogamy

Asexual reproduction in ferns, in which a sporophyte is produced directly from a prothallus without the union of gametes

apical

At the apex of an organ

Anthophyta

(see Angiospermae) antidromous Having the stipules joined by their outer margins, as in Alchemilla mollis (Rosaceae).

anthophore

An extension of the receptacle above the calyx that appears as a short stalk bearing the corolla, stamens, and ovary

antheriferous

Bearing anthers

auct.

non A phrase placed after a botanical plant name to signify that the name has been misapplied. It is followed by the name of the original author,

auct.

(auctorum) Of authors, used after a botanical plant name to indicate that that particular name has been accepted by various authors, but not by the original one.

atypical

Not conforming to type,

attenuate

Drawn out and gradually narrowing

acroscopic

On the side towards the apex.

acrophyll

One of the mature fronds of a climbing fern that occur in the upper part of the plant.

appendage

An attached subsidiary part,

assimilatory

Capable of converting inorganic substances into the constituents of the plant system,

asepalous

Without sepals

assurgent

Rising upwards.

ascidium

A little pitcher

ascending

Sloping or curving upwards

atactostele

A type of stele characteristic of monocotyledons, in which the individual vascular bundles are distributed throughout the ground tissue.

ascidiate

Bearing pitcher-shaped structures, as the leaves of Nepenthes

aril

An outgrowth of the funicle, forming an appendage or outer covering of a seed, e.g. the fleshy, scarlet outer covering of the seeds of Taxus (yew).

areole

One of the small areas surrounded by veins in a leaf with reticulate venation [202]; one of the small, spine-bearing areas on the stem of a cactus

arching

, arcuate Bending over, curved

access'ory

(accessio, something added), an addition or appendage ; ~ Buds, those additional to the axillary and normal buds, and frequently as¬suming their function Branches, those which spring from the fore¬going ; ~ Cell, the sister-cell of a guard-cell of a stoma ; ~ Fruits, parts which are conspicuous but form no part of the pistil, as the enlarged torus of the strawberry, a pseudo-carp ; - Gonid'ia, forma¬tions occurring in Mucorini besides the typical gonidia. accidental = adventitious, acci'sus (Lat.) denotes an end having an acute sinus between two rounded angles.

Appen'dage, Appen'dix

(Lat. an ad-dition), (1) apart added to another, as leaves are appendages to the stem, (2) a name given to processes of any kind, especially those of the perithecia of fungi ; (3) in the plural the term Appendices was formerly applied to suckers, such as the offsets of the Pineapple, appen'dent, appen'dens (appendo, I hang by), when the hilum is directed towards the upper part of the seed, which is sessile or nearly so on the placenta, as in stone-fruits, appendic'ulate, appendicula'tus (ap- pendicula, a small appendage), furnished with appendages ; ap- pen'dicled.

Article, Arlic'ulus (Lat.)

a joint; artic'ulated, articula'tus, jointed, separating freely by a clean scar, as in leaf-fall ; Articulation, a joint, popularly applied to the nodes of grasses.

Archegonium.

The female or egg-containing sex organ of higher cryptogams.

Arborescent.

Of treelike habit.

Autoploid.

A polyploid in which each of the 3 or more chromosome sets has been derived from the same species.

Ascending.

Rising up; produced somewhat obliquely or indirectly upward.

Adnate.

Grown to, organically united with another part, as stamens with the corolla; the fusion of unlike parts

Armature.

Any covering or occurrence of spines, barbs, hooks, or prickles on any part of the plant.

Appressed.

Closely and flatly pressed against; adpressed.

amphicarpic, amphicarpous

Producing two kinds of fruit, differing in one or more characters

albumen

Nutritive material stored within the seed.

Accessory Fruit.

A fruit, or assemblage of fruits, conspicuous by fleshy parts not part of the pistil, as the strawberry, whose fleshy receptacle is soft and edible and whose fruits (achenes) are embedded in its surface

Axis.

The main or central line of development of any plant or organ; the main stem.

Auricle.

An ear-shaped part or appendage, as the projections at the base of some leaves and petals

Aril (Arillus).

An appendage or an outer covering of a seed, growing out from the hilum or funiculus; sometimes it appears as a pulpy covering.

Antheridium.

In Cryptogams, the organ corresponding to an anther or male organs in flowering plants.In Cryptogams, the organ corresponding to an anther or male organs in flowering plants.

Anther.

The pollen-bearing part of the stamen, borne at the top of the filament or sometimes sessile.

Amphitropous.

Said of an ovule whose stalk (funiculus) is curved about it so that the ovule tip and stalk base are near each other

Abaxial.

The side of an organ away from the axis or center of the axis; dorsal. Abortive. Defective; barren; imperfectly developed.

Areole.

The open space formed by anastomosing veins; a small pit or raised spot, often bearing a tuft of hairs, glochids, or spines

Aposepalous.

Having the sepals distinct from one another, the calyx being com¬posed of separate elements; polysepalous

Annual. Of one season’s duration from seed to maturity and death.

Of one season’s duration from seed to maturity and death.

Albumen.

Starchy or other nutritive material accompanying the embryo; com¬monly used in the sense of endosperm, for the material surrounding the embryo.

Acaulescent.

Stemless, or apparently stemless; sometimes the stem is subterranean or protrudes only slightly; a descriptive rather than a morphological term

Awl-Shaped.

Narrow and sharp-pointed; gradually tapering from base to a slender or stiff point.

Articulate.

Jointed; provided with nodes or joints, or places where separation may naturally take place.

Acute.

Sharp, ending in a point, the sides of the tapered apex essentially straightor slightly convex

Ascidium.

A cup- or pitcher-shaped organ (as in Nepenthes leaves).

Armed.

Provided with any kind of strong or sharp defense, as of thorns, spines, prickles, barbs.

Asexual.

Sexless; without sex.

Acyclic.

Arranged in spirals, not in whorls

Actinomorphic.

Regular, symmetrical

Arachnoid.

Cobwebby by soft and slender entangled hairs; also spiderlike.

Aristate.

Bearing a stiff bristlelike awn or seta; tapered to a very narrow, much* elongated apex

Arcuate.

Curved or bowed.

Acicular.

Needle-shaped

Achene

a small, hard, dry

amphitropous (hemitropous)

Curved, so that both ends of the ovule are brought near to each other.

absolute

(absolutus,perfect,complete),actual, the opposite of relative.The absolute direction of an embryo may be inverted, but erect relatively to the carpel.

Axil.

Upper angle that a petiole or peduncle makes with the stem that bears it.

alien

Not native to the region concerned

allopolyploid

A polyploid of hybrid origin, containing sets of chromosomes from two or more different species,

amphistomatal, amphistomatic

With stomata on both upper and lower surfaces of the leaf,

alkaline soils

Soils with a pH value above 7.5.

Adherent.

A condition existing when two dissimilar organs or parts touch each other connivently but are not grown or fused together.

Adaxial.

The side toward the axis; ventral.

Acuminate.

Said of an acute apex whose sides are somewhat concave and taperto a protracted point.

Acorn.

The fruit of the oak (Quercus) and composed of a nut and its cup or cupule.

Acephalous.

Headless

Achene (akene).

A small dry indehiscent one-seeded fruit with tight thin pericarp

Axillary.

In an axil.

Awn.

A bristlelike part or appendage

Attenuate.

Showing a long gradual taper, applied to bases or apices or parts

Anterior.

Front; on the front side; away from the axis; toward the subtending bract.

Androecium.

The male element or household; the stamens as a unit of the flower

Alternate.

Any arrangement of leaves or other pans not opposite or whorled- placed singly at different heights on the axis or stem

Accumbent.

Lying against and face to face, as cotyledons

Appendage.

An attached subsidiary or secondary part, as a projecting part or a hanging part or supplement

Aphyllous.

Leafless.

Apetalous.

Without petals; petals missing.

Apiculate.

Terminated by an apicula, a short, sharp, flexible point

Androphore.

A stall: bearing the androecium

Androgynophore.

An axis or stalk bearing both stamens and pistil above the point of perianth attachment

Anther.

The pollen-bearing part of the stamen, borne at the top of the filament or sometimes sessile.

Anemophilous.

Wind-pollinated; the opposite of entomophilous.

Antheriferous.

Anther-bearing.

Annular.

In a ring or arranged in a circle.

Aggregate Fruit.

One formed by the coherence of pistils that were distinct in the flower, as blackberry (Rubus)

Abor'tion.

(abortio, a miscarriage),non-formation or incompletion ofa part ; abortive, aborti'vus, im-perfectly developed, as abortivestamens when filaments only ;abort'iens, becoming abortive.abra'ded, abra'sus, rubbed or scrapedoff.

Absorp'tion

(absorp'tio, a beverage), the act of imbibing liquids or gases.

Axile.

Belonging to the axis.

Abiogen'esis

spontaneous generation ; the assumed origin of living organisms from non-living matter.

Apocarpous.

With carpels separate, not united; frequently applied to a gynoecium of separate pistils.

Aestivation

The arrangement of the perianth or its parts in the bud. Vernation is ’eaf arrangement in the bud.

abrupt

abrup'tus, suddenly endingas though broken off ; abrupt'ly-acu'minate, having a point arisingfrom a broad extremity; pin'nate,a pinnate leaf ending with a pairof leaflets.

aerotropism

The growth movement of a plant in response to oxygen.

aestivation

The arrangement of the calyx or corolla in a flower bud.

aerotaxis

Movement in response to the source of oxygen.

aberrant

Not typical, differing from the normal form.

arundinaceous

Reed-like,

amplexicaul

Clasping the stem, but not completely encircling it.

amphitropous (hemitropous)

Curved, so that both ends of the ovule are brought near to each other

amphistomatal, amphistomatic

With stomata on both upper and lower surfaces of the leaf

amphiphloic siphonostele (solenostele)

A type of stele in which a central core of pith is surrounded first by a ring of phloem, then by a ring of xylem, followed by a second ring of phloem.

amphidiploid

An allopolyploid containing a diploid set of chromosomes from each of two different species.

amphicarpic, amphicarpous

Producing two kinds of fruit, differing in one or more characters,

allopatric

Of plant species or populations not growing in the same geographical area,

ament (amentum, catkin)

A spicate, often pendulous inflorescence of unisexual, apetalous flowers

alternate

Placed singly along the stem or axis, not opposite or whorled

alternation of generations

In the life cycle of ferns and fern allies, the alternation of a haploid gametophyte generation, reproducing sexually, with a diploid sporophyte generation, reproducing asexually.

allopolyploid

A polyploid of hybrid origin, containing sets of chromosomes from two or more different species,