Glossary - general

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Ebracteate – without bracts

Ebracteolate – without floral prophylls (bracteoles)

Ecarunculate – without a carunculus

Eccentric, excentric – one-sided, off-centre (e.g. an embryo)

Echinate – spinose, with projections tapering from a broad base to a more or less sharp apex; densely covered with spines

Echinate tectum (of pollen grains) – with an ornamentation of spines taller than 1 µm.

Echinulate tectum – microechinate tectum; with an ornamentation of spines smaller than 1 µm; diminutive of echinate

Ectexine (of pollen grains) – the outer part of the exine, which stains positively with basic fuchsin in optical microscopy and has higher electron density in conventionally prepared TEM sections

Ectoaperture (of pollen grains) – an aperture in the outer layer of the sporoderm (the outer aperture of a compound aperture)

Ectocarp, epicarp – outermost layer of pericarp, used in i.a. Commiphora

Ectomycorrhiza – fungal hyphae colonizing the host plant roots extracellularly; ectomycorrhizae consist of a hyphal sheath, mantle, covering the root tip and a Hartig net of hyphae surrounding the plant cells within the root cortex; in some cases the hyphae may also penetrate the plant cells, in which case the mycorrhiza is called ectendomycorrhiza

Edentate – without teeth

Efflorescence – the season of flowering

Effuse – loosely spreading, used of inflorescences in Caryophyllaceae

Efoliate – without leaves

Egg apparatus – the two (rarely one or three) synergids and the egg cell

Eglandular – without glands

Ejaculator – retinaculum; (Acanthoideae) an adaptation for seed dispersal; the capsule breaks into two elastic valves which coil back making the hook-like funicles oscillate; the funicle of the seed forms the hook-like ejaculator (retinaculum); due to the oscillations, the seeds are thrown out from the two carpels in a cross-wise manner

Elaiophore – oil producing epithelial or trichomatal glands in flowers

Elaiosome – oily appendage on a seed, fruit etc., often (always?) serving as a food body for ants or other insects, which then disperse the seed

Ellipsoid – a 3-dimensional shape, elliptic in the vertical plane

Elliptic – a 2-dimensional shape, broadest at the middle with two equal rounded ends, the sides more gently rounded

Elongate, elongated – stretched, long

Elongating – lengthening

Emarginate apex – with a distinct sharp notch

Emargination – notch

Embryo – the rudimentary plant contained in the seed, consisting of cotyledon(s), root apex and shoot apex

Embryo sac – see Megagametophyte

Embryogenesis – the formation (development) of the embryo, starting with the fertilization of the egg cell and the central cell by the sperm cells

Embryostega – embryotega; (Commelinaceae) the operculate testa taking the form of a callosity which covers the embryo

Emergences – multicellular projections from a surface

Emergent – coming out of, arising from

Emersed – rooting in water, but with the part under discussion raised above water level

Enantiostyly – a sexual polymorphism in which female organs are deflected to the left or right, resulting in mirror image flowers; probably functioning in promoting cross pollination

Enation – outgrowth of one organ from another; epidermal outgrowth

Encyclocytic stomata – see Cyclocytic stomata

Endexine (of pollen grains) – the inner part of the exine which remains relatively unstained with basic fuchsin in optical microscopy and has a lower electron density in conventionally prepared TEM sections

Endoaperture (of pollen grains) – an aperture in the inner layer of the sporoderm (the inner aperture of a compound aperture)

Endocarp – the innermost differentiated layer of the fruit wall; in a drupe the stone or putamen

Endodermis – the boundary between the cortex and the stele (the innermost layer of the cortex), which is a layer of living parenchyma cells where the intercellular spaces are impregnated with water-impermeable waxy suberin (in young endodermal cells deposited in Casparian strips); the endodermis is developmentally the innermost portion of the cortex and functions as storage tissue and, in the root, responsible for, i.a., water movement

Endogenous – growing or produced from within

Endogenous root – root growing or produced by growth from deep tissue

Endoglossum – an internal partition dividing the carpel into two chambers, one above the other (present in, i.a., many Malvaceae)

Endophytic – growing inwards; proliferating on the interior of an organ or a structure; with the tendency to grow inwards or on the inner surface of a structure or an organ

Endosperm – in a seed, the food-storage tissue that commonly surrounds the embryo; albumen; absent from seeds of some species when absorbed during development; usually oily and/or proteinaceous food reserve (starch, hemicelluloses, or amyloid and other polysaccharides may occur); the outer part of the endosperm, the aleurone layer, in monocotyledons with starchy endosperm commonly has other reserves than starch

Endosperm haustoria – branched or unbranched usually multicellular semi-invasive outgrowths from the developing endosperm, which absorb food materials from ovular and extra-ovular tissues in order to nourish the developing embryo; endosperm haustoria are formed at the micropylar and/or the chalazal end of the seed

Endostomal micropyle – the micropyle is formed from the inner integument

Endotegmen – the inner part of the tegmen

Endotesta – the inner part of the testa

Endotestal plug – an additional mechanical layer in the endotesta, forming a plug in the micropylar region

Endotestal seed coat – with the mechanical part in the inner layer of the testa

Endothecium – the subepidermal (hypodermal) cell layer of the anther wall; the endothecial cells often form lignified thickenings on the anticlinal and inner tangential walls as the anther matures, possibly assisting in the anther dehiscence; basic type of wall development: both secondary parietal cell layers (products of periclinal divisions of the primary parietal cells, themselves the product of the first division of the archesporial cells) of the anther wall usually divide further; dicot type of wall development: the inner cell may remain undivided; monocot type of wall development: the endothecium develops directly from undivided outer secondary parietal cells; in anthers with poricidal dehiscence which have lost their endothecium, epidermal cells are often markedly thick-walled forming an exothecium

Endothelium – see Integumental tapetum

End plates (of vessel elements) – see Perforation plates

Enneacolpate pollen grain – with nine colpi

Ensiform – sword-shaped; long and narrow, ending in a sharp point

Ensiform leaf – a sword-shaped leaf, usually equitant (i.a. in Iridaceae)

Entire – not divided; of margins, smooth, unbroken by serrations, teeth or other irregularities

Eophyll – the first fully expanded leaf produced by the seedling

Epaleate – without receptacle scales

Epedunculate – without a peduncle

Ephemeral – (1) very early caducous; (2) short-lived annual plant

Epiblast – (Poaceae) the first, vestigial, leaf of the plumule; the rudimentary secondary cotyledon; a flap of collar tissue at the base of the hypocotyl in a monocotyledon embryo or seedling arising opposite to the insertion of the cotyledon

Epicalyx – a group/whorl of bracts or modified calyx lobe stipules below the flower resembling an extra calyx (e.g. in Dipsacaceae, Malvaceae and many Rosaceae)

Epicarp – the outermost layer of the fruit wall

Epichile (of flowers) – (Orchidaceae) the apical (terminal, distal) part of the labellum, which is divided into two or three distinct parts or lobes

Epicormic shoot – arising from a tree trunk; often with foliage different from foliage of the crown

Epicortical – outside or on top of the bark

Epicotyl – the internode between the cotyledon(s) and the first leaf on the axis of an embryo or a seedling

Epicuticular wax – wax usually present on leaves and other plant organs; the wax consists mainly of straight-chain aliphatic hydrocarbons with a variety of substituted groups, which serve to minimize moisture loss and decay, reflect UV radiation and create a self-cleaning property (the lotus effect); examples are paraffins, alkyl esters, the asymmetrical secondary alcohol 10-nonacosanol, symmetrical secondary alcohols, primary alcohols (usually octacosan-1-ol), β-diketones, aldehydes and triterpenes

Epicuticular wax crystalloids – crystalline projections from the plant surface; asymmetrical secondary alcohols and β-diketones form hollow wax nanotubules, primary alcohols and symmetrical secondary alcohols form platelets

Epidermal – relating to the outermost layer of cells of a plant organ

Epidermis – the outermost layer of cells

Epigeal germination – germinating above ground; when cotyledons are brought above the ground surface; in epigeal seedlings the hypocotyl is elongated – Opposite: hypogeal germination

Epigyny – when the sepals, petals and stamens are apparently inserted on top of the ovary, the ovary thus being superior

Epipeltate – of any stalked structures (e.g. leaves or anthers) in which the upper (relative to the stalk) surface is apparently the adaxial, the stalk being attached to the abaxial surface (the normal condition)

Epipetalous – united with the petals, often appears as if implanted on the petals; usually referring to stamens

Epiphyllous – an inflorescence growing from the leaf (as in Helwingia, Phylloclinium, Phyllonoma)

Epiphyte (adj. epiphytic) – plant growing on and attached to another plant, without deriving nourishment from it

Episepalous – borne upon the sepals

Epitepalous – borne upon the tepals

Epitropous ovule – anatropous ovule with its dorsal raphe turned away from the axis when ascending, facing the axis when suspended

Epulvinate petiole – without a thickening (pulvinus)

Equator (of pollen grains) – the dividing limit between the proximal and distal faces

Equatorial – used in spheres or globe-like shapes to denote the area between the lower (or proximal) and upper (or distal) halves, halfway up and all around

Equitant leaf – base of one leaf clasping the base of the next leaf up and opposite, this in turn clasping the base of the next

Erect – upright

Erecto-patent – between spreading and erect

Ericoid – with small needle-like leaves

Ericoid leaf teeth – teeth united via multicellular hairs

Ericoid mycorrhiza – penetrating exclusively outer cortical cells in hair roots (consisting of endodermis, exodermis, tracheids, sieve tube and companion cell) covered by hyphae

Erose – irregularly toothed, eroded, appearing as if nibbled

Essential oil – see Ethereal oil

Estrophiolate – without a carunculus or strophiolus (appendage to the seed coat)

Ethereal oil – essential oil, volatile oil; volatile and often aromatic substance consisting of diterpenes, sesquiterpenes and other types of terpenes

Eucamptodromous venation – with a single primary vein, the secondary veins curved upwards and gradually diminishing distally within the margin and interconnected by a series of cross-veins without forming conspicuous marginal loops

Eunucleate sieve tube – sieve tube cell and companion cell formed from the same mother cell

Eustele – a type of stele in which the vascular cylinder appears in cross-section as a ring of collateral or bicollateral vascular bundles separated by medullary rays

Evanescent – soon disappearing; remaining for a very short time

Evergreen – retaining its leaves throughout the year – Opposite: deciduous

Exalbuminous seed – without endosperm; seed where the embryo occupies the whole space within the testa

Exarillate – without an aril

Exauriculate – without auricles

Excavated – hollowed out

Excurrent – running through to the apex and beyond, as a mucro

Exfoliating – coming off in large, thin-layered flakes

Exine (of pollen grains) – the outer wall layer

Exocarp – the outer layer of the fruit, often the thin epidermis of a stone fruit

Exodermis – a layer of cells, often lying immediately beneath the epidermis or velamen of the root, which is essentially a specialized hypodermis; exodermal cells often resemble those of the endodermis and usually possess a suberized lamella on the inside of the primary cell wall

Exogenous root – lateral root which is developed from the peripheral cell layers (e.g. just beneath the epidermis) of the main root

Exostome (of seed) – the small aperture or foramen in the outer layers of the ovule; the aperture through the outer integument of an ovule which, together with the endostome, completes the foramen

Exostomal aril – an aril developed from the exostome

Exostomal micropyle – the micropyle is formed from the outer integument

Exotegmen – the outer part of the tegmen

Exotesta – the outer part of the testa

Exotestal seed coat – with the mechanical part in the outer layer of the testa

Exothecium – see Endothecium

Exserted – projecting beyond; e.g stamens projecting beyond the corolla

Exstipellate – without stipels

Exstipulate – without stipules

Exterior – outer

Extra-axillary – beyond or outside the axil

Extra floral nectary – present outside the flower

Extragynoecial compitum – mucilage outside the stigmas that allows pollen grains landing on the mucilage to fertilize ovules in any of the carpels; in the strict sense applied to a cup at the apex of the gynoecium

Extrastaminal – beyond or outside the stamens

Extrorse anther – opening away from the centre of the flower, opening abaxially, or the anthers reflexing – Opposite: introrse

Extruded – pushed out

Exudate – liquid substance usually produced by the plant when wounded, deposited on its surface (bark or leaf), and then hardening