Glossary

-merous

Having a specified number of parts. In plants usually refers to floral parts: so a ‘5-merous’ flower has five sepals five petals five (or ten) stamens etc.

abaxial

(especially of surface of a leaf) Lower; facing away from the axis. (Cf. adaxial.)

abscission

Shedding of a part of a plant (e.g. leaf flower) due to old age or stress.

achene

Small dry indehiscent fruit that has a single seed (as in e.g. Polylepis).

acicular

Needle-shaped.

acorn

Fruit of Quercus; a single-seeded nut set in a woody cupule.

actinomorphic

Radially symmetrical. Applied to flowers with multiple lines of symmetry passing through their centre (e.g. Malus). (Cf. zygomorphic.)

acuminate

Narrowing gradually to a point.

acute

Sharply pointed.

adaxial

(especially of surface of a leaf) Upper; facing towards the axis. (Cf. abaxial.)

adherent

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

adnate

Fused with a different part by having grown together. (Cf. connate.)

allopatric

With a different distribution to that of another taxon. (Cf. sympatric.)

alluvial

Sediments deposited by rivers or soils derived from such material.

alternate

Attached singly along the axis not in pairs or whorls.

amphistomatic

With stomata on both sides of the leaf.

amplexicaul

(of leaf) With a base that clasps the stem but does not entirely surround it.

androdioecious

With only male or only hermaphrodite flowers on individual plants.

androecium

Collective name for the male sex organs in a flower (e.g. the stamens).

anther

Pollen-producing structure of flower at the tip of the filament; part of a stamen.

anthesis

Flowering period; when flower fully open and pollen beginning to be shed.

apex

(pl. apices) Tip. apical At the apex.

apiculate

With a short sharp point.

apocarpous

Flower in which the carpels are not fused together (e.g. many Magnolia spp.). (Cf. syncarpous.)

apomict

Taxon that reproduces only or regularly by apomixis.

apomixis

Reproduction without fertilisation usually by the asexual production of seeds (agamospermy) (as in e.g. Citrus Sorbus). Includes vegetative reproduction (stolons rhizomes suckers etc.) (as in e.g. Ulmus).

apophysis

The exposed tip of a seed scale in a mature closed conifer cone. Particularly significant in the genus Pinus.

appressed

Lying flat against an object.

apud

(after name(s) of the author(s) of a plant name) Literally ‘in the writings of’. Usually used where the name was published by one author or authors in the work of another.

archaeophyte

A non-native plant introduced to an area in ancient times (pre-1500 AD in the United Kingdom).

aril

Fleshy outgrowth produced at the base of a seed (as in e.g. Taxus). Often acts to attract animal seed-dispersal agents.

aristate

Bearing a stiff awn.

article

(in Casuarinaceae) Portion of branchlet between each whorl of leaves.

articulated

Jointed.

asl

Above sea-level.

assurgent

Curving or growing upwards.

attenuate

Gradually narrowing.

auricle

Small lobe or ear-like appendage.

auriculate

With one or more auricles.

authority

The author(s) of a plant name. The names of these authors are stated directly after the plant name often abbreviated. For example Quercus L. (L. = Carl Linnaeus); Rhus wallichii Hook. f. (Hook. f. = Joseph Hooker filius i.e. son of William Hooker). Standard reference for the abbreviations: Brummitt & Powell (1992).

autopolyploid

State of increased ploidy resulting from doubling of the normal two sets of chromosomes in a single species.

awn

Bristle.

axil

Angle between the upper side of a leaf and the stem.

axillary

Situated in an axil.

backcross

Cross between hybrid and one of the parent species.

berry

Fleshy indehiscent fruit with seed(s) immersed in pulp.

bifid

Divided up to halfway into two parts.

bilateral symmetry

See zygomorphic.

bisexual

See hermaphrodite.

bletted

(of fruit) Softened into edibility by frost or fungi.

bloom

Bluish or greyish waxy substance on leaves or fruits.

brachyblast

A short lateral flower-bearing shoot in Magnolia (primarily in species formerly in Michelia).

bract

Reduced leaf often subtending flower or inflorescence.

bract scale

(in female cones of Pinaceae) Papery structures that subtend the seed scales. Derived from modified leaves and may be included (e.g. Tsuga) or exserted (e.g. Pseudotsuga). In other conifer families bract scale and seed scale are fused.

bracteole

Small bract. Typically borne on pedicel of a flower.

branchlet

Small branch or twig usually less than a year old.

bud

Immature shoot protected by scales that develops into leaves and/or flowers.

bud scale

Reduced scale-like leaf partially enclosing a bud.

bullate

Puckered; with blister-like swellings on the surface.

buttress roots

Roots produced from the stem above ground that gradually fuse with the main stem providing additional mechanical support. buttressed (of stem) With buttress roots.

caducous

Falling off early.

caespitose

Tufted.

calcareous

Relating to lime- or chalk-rich soils or water.

calcicole

(of a plant) Growing on soil containing lime.

calcifuge

(of a plant) Avoiding soil containing lime (i.e. usually growing on acidic soil).

calyptra

Cap-like structure that covers some flowers. Derived from fused-together petals and/or sepals. In Eucalyptus for example flowers may have either a single calyptra (sepals and petals) or an inner one (petals) and an outer (sepals).

calyx

(pl. calyces) Outer whorl of the perianth. Composed of several sepals.

cambium

Meristematic (actively dividing) cells in the stem responsible for stem expansion (secondary growth).

campanulate

Bell-shaped.

camptodromous

Pattern of leaf venation whereby the lateral veins bend just before reaching the margin forming a loop. (Cf. craspedodromous.)

capitate

Head-like.

capitulum

(pl. capitula) Literally ‘head’; (in plants) head-like inflorescence of sessile (or almost sessile) flowers surrounded by ring of bracts (involucre). Typical of daisies Asteraceae.

capsule

Dry dehiscent fruit; formed from syncarpous ovary.

carpel

Female reproductive organ of a flower. Composed of ovary style and stigma. Typically several carpels are fused together in each flower (syncarpous). The number of them can be of taxonomic significance; it can often be assessed by counting the stigma branches or the chambers in the fruit.

cartilaginous

Firm and tough but flexible; gristly.

cataphyll

A reduced leaf. In Pinus cataphylls are scale-like non-photosynthetic leaves that line the stem.

caudate

With a long tail-like appendage.

cauliflorous

Exhibiting cauliflory.

cauliflory

Production of flowers directly on the trunk and stems (as in e.g. Cercis) rather than at stem apex.

CBD

Convention on Biological Diversity.

chaparral

Dense vegetation consisting of low scrubby trees and shrubs often with small leaves and spines.

chartaceous

Paper-like.

ciliate

Fringed with long hairs.

CITES

Convention on International Trade in Endangered Species of Wild Fauna and Flora.

clonal reproduction

Reproduction without the exchange of genetic material; asexual reproduction.

clone

Organism arising via vegetative or asexual reproduction.

coetaneous

The production of flowers/inflorescences during leaf emergence. (Cf. precocious serotinous.)

compound

Made up or consisting of two or more similar parts (e.g. a compound leaf is a leaf with several leaflets).

concolorous

Having the same colour throughout.

conduplicate

(of leaves) Folded once lengthwise.

cone

Term used here primarily to indicate the seed-bearing (female) structure of a conifer (‘conifer’ = ‘cone-producer’); otherwise known as a strobilus. A number of flowering plants produce cone-like seed-bearing structures including Betulaceae and Casuarinaceae.

cone scale

A scale in a cone. In Pinaceae this term generally refers to the seed scale while in other conifer families it refers to the combined complex of bract and seed scale.

connate

Fused together with a similar part. (Cf. adnate.)

convex

Having a rounded surface.

cordate

Heart-shaped (i.e. with two equal lobes at the base).

coriaceous

Leathery.

corolla

The inner whorl of the perianth. Composed of free or united petals often showy.

corymb

Unbranched inflorescence with lateral flowers the pedicels of which are of different lengths making the inflorescence appear flat-topped.

corymbose

In form of corymb.

cotyledon

The leaf/leaves of an embryo plant (‘seed leaves’) that may emerge from the seed and become photosynthetic or may remain within the seed.

craspedodromous

Pattern of leaf venation whereby the lateral veins run straight out to leaf margin. (Cf. camptodromous.)

crenate

With rounded teeth at the edge.

crenulate

With small rounded teeth at the edge.

crisped

Curled or crumpled.

Critically Endangered

IUCN Red List conservation category: ‘facing an extremely high risk of extinction in the wild’.

crustaceous

Somewhat hard elastic; resembling a hard crust or shell.

cultivar

(cv., cvs) Cultivated variety; cultivated plant selected for feature(s) that is/are useful and/or appealing to growers that is clearly distinct uniform and stable in its characteristics and remains so when propagated. A cultivar is indicated by single quotation marks around the name (e.g. Quercus rysophylla ‘Maya’). For the rules on naming a cultivar see the International Code of Nomenclature for Cultivated Plants.

cultivar group

See Group.

cuneate

Wedge-shaped.

cupular

Cup-shaped; relating to the cupule.

cupule

Cup-shaped structure formed from coalescent bracts. Typical of Fagaceae and Nothofagaceae. May be dehiscent (as in e.g. Castanea) or indehiscent (as in e.g. Quercus).

cusp

A pointed end; curves meeting in a point.

cuspidate

Ending abruptly in a sharp point.

cyme

Branched determinate inflorescence with a flower at the end of each branch. cymose In the form of a cyme.

Data Deficient

IUCN Red List conservation category: ‘there is inadequate information to make a direct or indirect assessment of its risk of extinction based on its distribution and/or population status’.

dbh

Diameter (of trunk) at breast height. Breast height is defined as 4.5 feet (1.37 m) above the ground.

decurrent

Running down as when a leaf extends along a stem.

decussate

Leaf arrangement where the leaves are in opposite pairs each pair at right angles to the preceding pair (as e.g. the scale leaves of Cupressaceae).

deflexed

Bent or turned downwards.

dehiscent

Opening naturally. (Cf. indehiscent.)

deltoid

Triangular.

dentate

With evenly triangular teeth at the edge. (Cf. crenate teeth rounded; serrate teeth saw-like.)

denticulate

Minutely (triangularly) toothed.

determinate

A form of inflorescence in which the terminal flower is the first to open preventing further extension of the inflorescence axis. (Cf. indeterminate.)

dichasium

A type of cyme with lateral branches on both sides of the main axis.

dichotomous

Forked dividing into two.

digitate

Hand-like; palmate.

dimorphic

Occurring in two forms.

dioecious

With male and female flowers on separate plants.

dioecy

The condition of being dioecious.

discoid

Flat and circular.

disjunct

Discontinuous; (of a distribution pattern) the range is split into two or more distinct areas.

distal

Situated away from point of attachment. (Cf. proximal.)

distichous

Arranged in two vertical ranks.

divaricate

Widely spreading greatly divergent. Many trees and shrubs from New Zealand have a divaricating form particularly when young whereby the stems become interlaced producing a ‘wire-netting’ effect.

divergent

Spreading from the centre.

DNA

Deoxyribose nucleic acid the principal genetic material.

domatia

Cavity or tuft of hairs that acts as a shelter for insects or other creatures.

dorsiventral flattening

Where a structure is flattened from top to bottom rather than from side to side.

drupe

A fleshy dehiscent or indehiscent fruit with one to several seeds each enclosed in a hard endocarp (the stone).

ellipsoid

An elliptic solid.

emarginate

Notched at the apex.

Endangered

IUCN Red List conservation category: ‘considered to be facing a very high risk of extinction in the wild’.

endemic

(of a plant or an animal) Found in a native state only within a defined region or country.

endocarp

Innermost layer of the fruit wall. Can be membranous and indistinguishable from the other layers of the fruit wall or may be hard woody and distinctive (see drupe).

entire

With an unbroken margin.

epicalyx

Whorl of sepal-like organs just outside the true calyx.

epicarp

Outermost layer of the fruit wall; the ‘skin’ on fruits such as apples and plums.

epicormic

(of shoot) Growing out from trunk or major branches.

epidermis

Outermost layer of cells (e.g. covering leaves).

epimatium

Expanded fleshy seed-bearing bract scale enclosing the seed in Podocarpaceae.

epiphyte

Plant growing on trees but not parasitic on the host.

epistomatic

Possessing stomata only on upper side of leaf.

equisetoid

Resembling the growth of an Equisetum (horsetail).

ex

(appearing before the author(s) of a plant name) Indicates the author who published the plant name validly. For example Quercus floribunda Lindl. ex A. Camus: ‘ex’ denotes that the latter author (Aimée Camus) published the name validly; the name had been used previously by the former author (John Lindley) but had not been validly published by him.

exserted

Protruding; pushed out.

Extinct

IUCN Red List conservation category: ‘there is no reasonable doubt that the last individual [of taxon] has died’.

Extinct in Wild

IUCN Red List conservation category: ‘known only to survive in cultivation in captivity or as a naturalised population (or populations) well outside the past range’.

extrafloral

Outside the flower. Used to describe nectaries situated on vegetative parts of a plant.

extrapetiolar

Outside the petiole. Used to describe stipules that are attached to the stem rather than to the petiole.

F1

A first-generation hybrid between two individuals.

F2

The second generation of progeny from an original hybridisation event; derivatives from the generation.

facial pair

In the Cupressaceae the scale leaves are arranged in alternating pairs (see decussate). The pair comprising the upper and lower leaves are the facial pair. (Cf. lateral pair.)

falcate

Sickle-shaped.

family

A group of genera more closely related to each other than to genera in other families. Names of families are identified by the suffix ‘-aceae’ (e.g. Myrtaceae) with a few traditional exceptions (e.g. Leguminosae).

farinose

Covered with fine powder. (Cf. mealy.)

fascicle

Close cluster or bundle; reduced short shoot of Pinus.

fascicle sheath

Cluster of membranous bud scales at the base of the fascicle in Pinus.

fastigiate

(of a tree or shrub) Narrow in form with ascending branches held more or less parallel to the trunk.

ferruginous

Rust-coloured.

filament

(in a plant) Stalk of a stamen supporting the anther.

filiform

Thread-like.

fimbriate

Fringed with edge dissected into long narrow lobes.

flabellate

Fan-shaped.

flush

Coordinated growth of leaves or flowers. Such new growth is often a different colour to mature foliage.

fluted

Channelled or grooved.

foliose

Leaf-like.

follicetum

Body made up of several follicles.

follicle

Dry dehiscent fruit containing numerous seeds derived from a single carpel.

form

(f.) Lowest taxonomic rank (forma) into which an organism is normally classified. Usually showing minor differentiation in only one character and not forming distinct populations.

fusiform

Spindle-shaped; a gradually tapering rod.

fynbos

Extremely biodiverse vegetation in the Western Cape of South Africa dominated by short finely branched shrubs.

galbulus

The fruit of Juniperus; a modified cone that becomes fleshy as it matures.

gallery forest

Thin strip of forest adjacent to a river in an otherwise unwooded landscape.

garrigue

Short Mediterranean scrubland.

genus

(pl. genera) A group of species more closely related to each other than to species in other genera. generic Of genus.

germplasm

Seed.

glabrous

Lacking hairs smooth. glabrescent Becoming hairless.

glandular

Bearing glands.

glaucescent

Becoming glaucous; (incorrectly) slightly glaucous.

glaucous

Grey-blue often from superficial layer of wax (bloom).

globose

globularSpherical or globe-shaped.

group

(or cultivar group) Collective name for a number of cultivars within a genus or species with similar characteristics. A very useful modern concept enabling the naming of many similar plants without the need to provide a cultivar name for each: so for seed-raised plants that come nearly true from seed (as e.g. Quercus texana New Madrid Group); or for the progeny of a repeatable hybridisation; or for variants of a species that cannot be maintained as distinct entities by taxonomists but have horticultural merit and need to be distinguished. ‘Group’ is always included in the name. Named cultivars may be selected from within a cultivar group.

gymnocarpy

Bare seeds protruding from the cone in Juniperus due to insect damage.

gynoecium

The female sex organs in a flower (e.g. carpels).

herbarium

A collection of preserved plant specimens; also the building in which such specimens are housed.

herbarium specimen

A plant specimen preserved (usually by drying or pickling) and maintained to provide information for botanists particularly taxonomists.

hermaphrodite

Having both male and female parts in a single flower; bisexual.

hesperidium

Type of berry in which the flesh is divided into segments with tough and leathery outer skin (as in e.g. Citrus).

heteroblasty

Production of different leaf forms at different ages. Very common in New Zealand native plants (e.g. Elaeocarpus hookerianus) and many Araliaceae.

hilum

Scar on seed from its point of attachment in the ovary. Particularly prominent on the large seeds of Aesculus.

hirsute

Covered in rough coarse hairs.

hyaline

Thin colourless translucent.

hybrid

Plant originating from the cross-fertilisation of genetically distinct individuals (e.g. two species or two subspecies).

hybrid swarm

A group or population of hybrids that exhibit a range of characters between those of the parents.

hybrid vigour

Increased expression of characteristics in hybrids when compared with the parent taxa.

hypanthium

Cup-shaped or tubular structure at the base of a flower (‘floral cup’) formed by enlargement of the receptacle and/or the bases of the floral parts.

hypogynous

With ovary situated below floral parts (inferior).

hypostomatic

With stomata only on lower side of leaf.

IDS

International Dendrology Society sponsors of this book.

ILDIS

International Legume Database & Information Service.

imbricate

Overlapping.

imparipinnate

Odd-pinnate; (of a compound leaf) with a central rachis and an uneven number of leaflets due to the presence of a terminal leaflet. (Cf. paripinnate.)

included

(botanical) Contained within another part or organ.

indehiscent

Not opening naturally; remaining closed at maturity. (Cf. dehiscent.)

indeterminate

A form of inflorescence in which the outer or lower flowers open first and the inflorescence axis continues to grow. (Cf. determinate.)

Index Seminum

Seedlist issued by a botanic garden for exchange purposes.

indigenous

Native to an area; not introduced.

indumentum

A covering of hairs or scales.

inflorescence

Flower-bearing part of a plant; arrangement of flowers on the floral axis.

infra-

Below the rank of. As in ‘infrageneric’ ‘infraspecific’ referring to subdivisions of these taxa.

infructescence

Fruit-bearing part of a plant; derived from an inflorescence.

INRA

Institut National de la Recherche Agronomique (French National Institute for Agricultural Research).

interfertile

Capable of interbreeding with another species or species to give hybrids.

intergeneric

(of hybrids) Formed by fertilisation between species of different genera.

internode

Section of stem between two nodes.

interspecific

(of hybrids) Formed by fertilisation between different species.

introgression

Incorporation of genes from one species into the genotype of another through repeated hybridisation or repetitive backcrossing between a hybrid and one of its parents.

involucre

A ring of bracts surrounding an inflorescence.

involute

Rolled inwards at margins (i.e. towards upper surface).

IPNI

International Plant Names Index. Database of plant names and associated details.

IUCN

World Conservation Union (formerly the International Union for the Conservation of Nature).

karst

Landscape area formed by the dissolution of limestone by water with much exposed rock. Karst areas are usually rather arid due to the free-draining conditions.

keel petal

(in the flowers of some legumes) The two front petals fused together to form a keel-like structure.

keeled

With a prominent ridge.

key

(of fruit) Vernacular English term for winged samaras (as in e.g. Acer Fraxinus Ulmus)

lamina

Leaf blade.

lanceolate

Lance-shaped; broadest in middle tapering to point.

lateral pair

(in Cupressaceae) The pair of lateral scale leaves. (Cf. facial pair.)

latex

Colourless or milky sap produced by some plants (e.g. many Apocynaceae Euphorbiaceae Moraceae).

laurisilva

Humid subtropical forest with high preponderance of Lauraceae; characteristic forest of Macaronesian islands.

lax

Loose or open.

leaflet

Leaf-like segment of a compound leaf.

Least Concern

IUCN Red List conservation category: ‘does not qualify for Critically Endangered Endangered Vulnerable or Near Threatened. Widespread and abundant taxa are included in this category.’ ‘Lower Risk’ was formerly used and many tree species are still so-categorised in the Red List.

lectotype

Specimen or illustration chosen to serve as the type specimen for a taxon in cases where one was not designated by the original author.

legume

Two-valved fruit formed from a single carpel widely known as a ‘pod’ typical of most members of the legume family (Leguminosae). The word has come to be used as much for members of the family as for their distinctive fruits.

lenticel

Pore on the stem. lenticellate Bearing lenticels.

lenticular

Lens-shaped.

liana

Woody climber growing from ground into canopy.

lignotuber

Woody tuber developed in the axils of the cotyledons or the first few leaf pairs. Common in Eucalyptus where they provide a means for regeneration after a fire.

ligulate

Tongue-shaped.

linear

Strap-shaped.

lobe

Division of a leaf or other object. lobed Bearing lobes.

locule

Compartment of the ovary. loculicidal (of dehiscent fruit) Splitting between the locules. (Cf. septicidal.)

lomentum

Fruit derived from a single carpel which splits into one-seeded sections (as in e.g. Sophora).

Lower Risk

See Least Concern.

lustrous

Smooth and shiny.

Macaronesia

The subtropical islands of the north Atlantic: the Azores Canary Islands Cape Verde Islands and Madeira.

Malesia

Floristic region including the Malay Peninsula Indonesia the Philippines and New Guinea.

mallee

Multistemmed growth form of many Eucalyptus species in which numerous stems arise from ground level from an individual plant (from the lignotuber).

maquis

Tall Mediterranean drought-resistant shrubland.

matorral

Scrub vegetation composed of low-growing woody plants derived by degradation of Mediterranean forest.

mealy

Covered with coarse flour-like powder. (Cf. farinose.)

medial

Relating to the middle or median.

mesa

Flat-topped steep-sided mountain often in arid areas.

mesic

(of habitat or site) Moderately moist. (Cf. xeric.)

mesocarp

Middle layer of the fruit wall in between the epicarp and the endocarp; the ‘flesh’ of fruits such as plums.

mesophytic

(of a plant) Growing in moist (mesic) habitats.

metapopulation

‘Population of populations’ usually referring to scattered populations of the same species.

microspecies

Species distinguished on the basis of minute differences of morphology. Generally used only for species that reproduce via apomixis (e.g. Sorbus).

microsporophyll

Pollen-producing scales in the male cones of conifers.

midrib

midveinCentral and principal vein in a leaf.

moniliform

Like a string of beads.

monoecious

With male and female flowers on the same plant.

monoecy

The condition of being monoecious.

monograph

Taxonomic account of a single genus or family.

monomorphic

Occurring in one form.

monophyletic

(of a group of taxa) With a single ancestor; part of a natural lineage believed to reflect evolutionary relationships accurately (n. monophyly). (Cf. paraphyly polyphyly.)

monopodial

With simple stem/axis extending by growth of the apical bud and bearing lateral branches. (Cf. sympodial.)

monoseed

With a single seed. Many junipers in Juniperus section Sabina produce monoseed cones.

monospecific

(of a genus) Including only one species (as e.g. Aextoxicon).

montane

Of mountains.

morphology

The visible form of an organism.

morphometric

From the measurement of shape.

mucro

Short straight point. mucronate Bearing a mucro.

mutation

Novel characteristic arisen as a result of a spontaneous genetic change mutant Individual with a mutation.

mycorrhiza

(pl. mycorrhizae) Beneficial fungus associated with the roots of a plant. Different forms of association occur (e.g. arbuscular ectendo- endomycorrhizae) depending on how the fungus and the plant roots interact.

Near Threatened

IUCN Red List conservation category: ‘does not qualify for Critically Endangered Endangered or Vulnerable now but is close to qualifying or is likely to qualify for a threatened category in the near future’.

nectary

Gland or surface from which nectar is secreted.

node

Point on a stem where one or more leaves are borne.

nomen ambiguum

(nom. ambig.) (of plant name) Name whose application is ambiguous which could cause confusion.

nomen illegitimum

(nom. illeg.) (of plant name) Illegitimate name published with some contravention of the International Code of Botanical Nomenclature and therefore invalid.

nomen nudum

(nom. nud.) (of plant name) Name published without a description and therefore invalid.

notho-

(prefixed to the name of a taxon) Denotes hybrid origin. Hence nothogenus. nothospecies nothovar.

nut

Dry indehiscent single-seeded fruit with woody outer wall.

nutlet

Small nut. Term may also be applied to an achene or part of a schizocarp.

ob-

(prefixed to technical term) Inverse of.

oblanceolate

Inversely lanceolate; broadest towards apex.

oblate

Almost globose but flattened at apices; subglobose.

obtuse

Blunt.

open pollinated

Pollinated without control. Where plants are open pollinated unexpected hybrids may occur.

orbicular

Circular.

ovary

Lowest part of the carpel containing the ovules; later developing into the fruit.

ovate

Egg-shaped; broadest towards the stem.

ovoid

Egg-shaped solid.

ovule

Structure inside ovary that when fertilised becomes a seed.

páramo

Vegetation above the treeline in tropical South America mostly grasslands and scrub.

palmate

Roughly hand-shaped; (of a leaf) divided partially or fully to the base with all the leaflets arising from the tip of the petiole (as in e.g. Aesculus).

panicle

A much-branched inflorescence. paniculate Having the form of a panicle.

papillae

Small protuberances on surface of petal or leaf sometimes hair-like in appearance. papillose Bearing papillae.

paraphyletic

(of a taxon usually at generic or family level) With a common ancestor but some of the other descendants of that ancestor are excluded from the taxon for subjective reasons of the taxonomist (n. paraphyly). Such a classification is therefore not ‘natural’. (Cf. monophyly, polyphyly.)

paripinnate

Even-pinnate; (of a compound leaf) with a central rachis and an even number of leaflets (no terminal leaflet). (Cf. imparipinnate.)

pectinate

Comb-like.

pedicel

Stalk of a single flower.

pedicellate

Borne on pedicel.

peduncle

Stalk of inflorescence.

pedunculate

With a peduncle.

peltate

Disc-shaped and attached at centre of lower surface to a stalk (e.g. leaf of Nasturtium Tropaeolum majus).

pendent

Hanging.

perfect

(botanical) All parts present and functional. Usually referring to both androecium and gynoecium of a flower.

perhumid

Always moist or wet. Usually referring to tropics.

perianth

Calyx and corolla. Term used especially when petals and sepals are not easily distinguished from each other.

perular scale

Basal scales in a leaf bud.

petal

Single segment of the corolla. Often brightly coloured and an attractant for pollinators.

petaloid

Petal-like. May refer to sepals or stamens modified into a petal-like form.

petiolate

Bearing a petiole.

petiole

Leaf stalk.

petiolule

Stalk of a leaflet in a compound leaf.

phenology

The seasonal timing of events in the life cycle of a plant or animal and the study thereof.

phloem

Sap-carrying vascular tissue.

phototropism

A plant’s response to light: shoots growing towards it roots away.

phyllichnia

(in Casuarinaceae) Longitudinal ridges on articles.

phyllode

A petiole taking on the form and functions of a leaf (as in e.g. Acacia).

phylloid

Leaf-like.

pilose

Softly hairy.

pinna

(botanical) Primary division of a compound leaf.

pinnate

(of a compound leaf) With leaflets/ veins along each side of a central rachis/midrib.

pinnatifid

(of a leaf) Dissected into large teeth or lobes that reach no more than halfway to the midvein.

pinnatinerved

Leaf venation with a pinnate arrangement.

pinnatisect

(of a leaf) Dissected into large teeth or lobes that reach nearly to the midvein (i.e. not completely pinnate).

pinnule

Secondary division of a compound leaf.

pioneer species

Early colonists of disturbed areas.

pistillate

Female referring to female plants (dioecy) or flowers (monoecy) or the female parts of a hermaphrodite flower.

plicate

Folded more than once lengthwise.

ploidy

Number of chromosomes.

podzol

A soil characterised by a superficial layer of raw humus above a generally grey layer of mineral soil depleted of iron sesquioxides and aluminium.

pollen

Small grains that contain the male reproductive cells. Produced in the anther.

pollination

Act of placing pollen on the stigma. Various agents may initiate pollination including animals and the wind.

polygamous

With unisexual and bisexual flowers on same plant.

polyphyletic

(of a taxon) Including entities descended from different ancestors and evolutionary lineages grouped usually as a result of superficial similarities (n. polyphyly). The grouping is therefore not ‘natural’. (Cf. monophyly paraphyly.)

pome

Fleshy fruit with leathery core. Typical of Rosaceae subfamily Maloideae (e.g. Malus).

precocious

The production of flowers/inflorescences prior to leaf emergence. (Cf. coetaneous serotinous.)

propagule

Vegetative structure that can become detached and give rise to a new plant.

prostrate

Lying flat.

protologue

Text of first publication of a taxon’s name.

proximal

Situated towards point of attachment. (Cf. distal.)

pruinose

Covered with a waxy bloom (as found on a plum).

puberulent

Minutely pubescent.

pubescence

Hairiness.

pubescent

Covered in hairs.

pulvinus

(pl. pulvini) Enlarged portion of petiole or rachis.

punctuate

Marked with dots depressions or glands.

pyrene

Stone of a drupe consisting of the seed and the surrounding endocarp.

pyriform

Pear-shaped.

raceme

Unbranched inflorescence with flowers produced laterally usually with a pedicel. racemose In form of raceme.

rachilla

(pl. rachillae) Secondary axis in an inflorescence.

rachis

Central axis of an inflorescence cone or pinnate leaf.

radial symmetry

See actinomorphic.

ramiflory

Production of flowers directly on the branches. Included within cauliflory. ramiflorous Exhibiting ramiflory.

receptacle

Enlarged end of a flower stalk that bears floral parts; (in some Podocarpaceae) fleshy structure bearing a seed formed by fusion of lowermost seed scales and peduncle.

reflexed

Folded backwards.

relict species

Species that has survived unchanged from a previous age (a ‘living fossil’) or become geographically isolated from related species due to a change in circumstances.

reniform

Kidney-shaped.

resin canal

Minute tubes containing resin-producing cells in the leaves and wood of conifers.

resin gland

Small gland on leaf or other surface exuding resin.

reticulate

Arranged in a net-like manner.

retuse

Slightly notched at apex.

revolute

Rolled downwards at margin.

rhizome

Persistent horizontal subterranean stem bearing roots and shoots. rhizomatous Having or resembling a rhizome.

rhombic

Diamond-shaped. rhomboid Diamond-shaped solid.

rugose

Wrinkled.

s.l.

Abbreviation of sensu lato. In the broad sense.

s.n.

Abbreviation of sine numero. Without a number.

s.s.

Abbreviation of sensu stricto. In the narrow sense

sagittate

Arrowhead-shaped.

samara

Dry indehiscent winged fruit usually with a single seed (as in e.g. Acer Fraxinus Ulmus. Also called a ‘key fruit’.

sarcotesta

Fleshy outer coat on a seed (as in e.g. Ginkgo).

scabrous

Rough to the touch as a result of minute projections. scabrid Slightly less rough.

scarious

Thin dry and membranous.

schizocarp

Dry fruit that breaks up into sections at maturity.

sclereid

Hard thick-walled cell; part of the sclerenchyma the support tissue in plants. Individual sclereids also occur in the flesh of Pyrus fruits giving their characteristic gritty texture.

sclerophyllous

With tough leathery usually evergreen leaves. Typical of trees and shrubs from warm dry climates.

section

(sect.) Subdivision of a genus.

seed scale

(in female cones of Pinaceae) Seed-bearing structure. In other conifer families the seed scale and the bract scale are fused together.

self-coppicing

(of vigorous tree or shrub: e.g. Corylus) Producing new stems at ground level without having been damaged.

sensu lato

(s.l.) In the broad sense.

sensu stricto

(s.s.) In the narrow sense.

sepal

Single segment of the calyx. Protects the flower in bud.

septicidal

(of fruit) Splitting along the partitions (septa) rather than along the walls of the locules. (Cf. loculicidal.)

serotinous

The production of flowers/inflorescences after leaf emergence; (of cones/dry fruits) closed until scorched by fire (as in e.g. Banksia Pinus). (Cf. coetaneous precocious.)

serrate

With saw-like teeth at edge. serrulate Minutely serrate.

sessile

Lacking a stem or stalk.

setose

Bristly.

simple

(of a leaf) Unlobed or undivided.

sinuate

(of a flat leaf) With margins that wind strongly inwards and outwards.

sinus

Recess between two lobes or teeth on leaf margin.

sp. nov.

Abbreviation of species nova. A newly discovered species for which no epithet has been formally published.

spathulate

Spatula-shaped.

species

(sp. pl. spp.) Division of a genus; group of plants or animals with similar characters all more closely related to each other than to any other similar group. specific Of species.

spicate

Spike-like.

spike

Inflorescence in which flowers sessile on the main axis.

spinose

Spiny.

sporophyll

Specialised leaf or structure derived from a leaf that bears spore-producing bodies. The seed scale of a conifer cone is a megasporophyll while the scales in a male conifer cone are microsporophylls.

SSC

Species Survival Commission (of the IUCN).

stamen

Male reproductive organ of flower. Usually composed of an anther and a filament.

staminal ring

Ring of stamens.

staminate

Male referring to male plants (dioecy) or flowers (monoecy) or the male parts of a hermaphrodite flower.

staminode

Sterile or abortive stamen. Can be petaloid or converted into a nectary.

standard petal

(in the flowers of some legumes) Large upper petal; also known as ‘vexillum’.

stellate

Star-shaped.

stigma

(in a flower) The part of the carpel that receives pollen and on which it germinates. May be at the tip of a short or long style or may be reduced to a stigmatic surface at the apex of the ovary.

stipitate

Having a stalk (stipe) or borne upon one.

stipule

An outgrowth arising at the base of the petiole. Often paired. May be foliose or spinose caducous or persistent. stipulate Bearing stipules.

stoma

(pl. stomata) Small pores on the leaves (and young stems) that allow for gas exchange.

strangler

An epiphytic vine or tree whose roots extend down the trunk of a supporting tree and coalesce around it eventually strangling it.

stratify

(horticultural) Expose seeds to cold weather to promote germination.

striated

Bearing fine longitudinal stripes grooves or ridges.

strigose

Bearing stiff hairs or bristles.

strobilus

Cone. Used here to indicate male pollen-producing structure in conifers which may or may not be cone-shaped.

style

Generally an elongated structure arising from the ovary bearing the stigma at its tip.

stylopodium

Persistent remains of the style at tip of an acorn.

sub-

(prefixed to tech. term) Beneath; less than; approximately.

subspecies

(subsp.) Taxonomic rank for a group of organisms showing the principal characters of a species but with significant definable morphological differentiation. A subspecies occurs in populations that can occupy a distinct geographical range or habitat.

subulate

Awl-shaped.

symbiotic

(of two organisms) Dissimilar but closely associated living together in a mutually beneficial manner.

sympatric

With the same distribution as another taxon (or with overlapping distribution). (Cf. allopatric.)

sympodial

With stem/axis terminating (perhaps after the production of a flower) and growth continuing via lateral branches. (Cf. monopodial.)

syncarpous

Flower in which the carpels are fused together to form a single unit. (Cf. apocarpous.)

synonym

(syn.) (botanical) An alternative or former name for a taxon usually considered to be invalid (often given in brackets). Synonyms arise when a taxon has been described more than once (the prior name usually being the one accepted as correct) or if an article of the International Code of Botanical Nomenclature has been contravened requiring the publishing of a new name. Developments in taxonomic thought may be reflected in an increasing list of synonyms as generic or specific concepts change over time.

taiga

Region of sparse coniferous forest in northern latitudes.

taxon

(pl. taxa) Group of organisms sharing the same taxonomic rank (family genus species infraspecific variety).

taxonomy

Classification usually in a biological sense.

tepal

Perianth segment. Petal/sepal of a flower in which the two structures cannot be differentiated (as in e.g. Magnolia).

terete

Like a slender tapering cylinder.

ternate

In threes.

terrestrial

Growing in the ground.

thyrse

Mixed inflorescence in which main axis indeterminate but secondary axes determinate. thyrsoid In form of thyrse.

Tibet

Traditional English name for the formerly independent state known to its people as Bod now the Tibet (Xizang) Autonomous Region of the People’s Republic of China. The name Xizang is used in lists of Chinese provinces.

tomentum

Dense layer of soft hairs. tomentose With tomentum.

trichome

Hair-like growth from epidermis. May be glandular.

trifoliate

With three leaves or leaflets.

trifoliolate

With three leaflets.

trinerved

Three-nerved with the veins (nerves) all arising from near the base of the leaf.

triplinerved

Three-nerved with the two lateral veins (nerves) arising from the midrib above the base of the leaf.

TROBI

Tree Register of the British Isles.

TROI

Tree Register of Ireland.

trullate

Trowel-shaped.

truncate

Appearing as if cut off.

tuber

Underground storage organ derived from root or stem.

tubercle

Small tuber; small rounded projection or protruberance. tuberculate Bearing tubercles.

turbinate

Spinning-top shaped; inversely conical; obconical.

tylose

An obstruction of a connective vessel (xylem or phloem) caused by the intrusion of part of another cell.

type specimen

A herbarium specimen cited in a taxonomic account to define a particular species or other taxon.

umbel

Inflorescence in which pedicels all arise from same point on peduncle. May be flat-topped (as in e.g. Umbelliferae) to spherical (as in e.g. Araliaceae). umbellate In form of umbel.

umbellaster

Basic inflorescence unit in Eucalyptus; a group of flowers (with terminal bud ending in a flower) more or less arising from one point. May derive from cyme thyrse or panicle.

umbilicate

Having a small depression; resembling the human belly-button (umbilicus).

umbo

Boss or protuberance particularly that in centre of apophysis of pine seed scale. umbonate Bearing an umbo.

undulate

Wavy.

unicellular

Single-celled.

unifoliolate

Having one leaflet thus appearing to have simple (not compound) leaves.

unisexual

Having only male or female organs in a flower.

urceolate

Urn-shaped.

USDA

United States Department of Agriculture.

USDA Hardiness Zone

Defined in USDA Plant Hardiness Zone Map which divides the North American continent into ten zones each representing an area of winter hardiness for plants based on average annual minimum temperatures.

USNA

United States National Arboretum.

valvate

(of similar parts of a plant: e.g. petals) Meeting without overlapping; (of dehiscent fruit) opening via valves.

variety

(var.) Taxonomic rank (varietas) grouping variants of a species with relatively minor differentiation in a few characters but occurring as recognisable populations. Often loosely used for rare minor variants more usefully ranked as forms.

venation

Pattern of veins (nerves) especially in a leaf.

vernalisation

The priming of a plant response (e.g. germination flowering) by exposure to low temperatures in winter.

vernation

Arrangement of a leaf in its bud.

vesicle

Small bladder or sac.

vicariants

Similar usually related taxa found in similar habitat but in distant locations.

villous

Covered in long shaggy hairs.

viscid

Sticky.

Vulnerable

IUCN Red List conservation category: ‘facing a high risk of extinction in the wild’.

whorl

Arrangement of three or more organs (leaves flowers) around a central axis. whorled Arranged in a whorl.

wing petal

(in flowers of some legumes) The two lateral petals.

winter bud

Vegetative buds developed in the autumn and persisting through winter until spring when they burst.

x

(multiplication sign) Placed before an epithet indicates a hybrid; between two parents denotes a cross between them.

xeri-adapted

Adapted to tolerate dry conditions.

xeric

(of habitat or site) Arid. (Cf. mesic.)

xerophytic

(of a plant) Growing in arid (xeric) habitats.

Xizang

See Tibet.

xylem

Vascular tissue carrying water and minerals from roots.

zoopharmacognosy

Self-medication by animals.

zygomorphic

Bilaterally symmetrical. Term applied to flowers with a single line of symmetry passing through the centre (e.g. Salvia). (Cf. actinomorphic.)

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