Xylem cells are the following: – vessels or tracheids. Vessels are told perfect when there is no transverse wall and when all elements are joined together to reach a length that can reach many meters. Tracheids are imperfect vessels because they have a transverse wall with a lumen more or less important. Tracheids are present in basal (primitive) vascular plants such as Ferns and allies, or Gymnosperms.
Phloem cells are the following: – sieve elements that are joined together to form sieve tubes, – companion cells, transfer cells: companion cells perform metabolic functions for the sieve elements (ATP or proteins synthesis…); transfer cells help sieve elements to transfer metabolites, – intermediary cells are sometimes present to help connections between bundle sheath, parenchyma cells and sieve elements.
Cytoplasm is outside the nucleus and inside the plasmalemma, the membrane of the cell. It includes: – cytosol, a semi-liquid solution in which organelles are found, – cytoskeleton, e. g. microtubules and microfilaments, – and different organelles such as endoplasmic reticulum, Golgi apparatus, mitochondrions and chloroplasts, lysosomes, peroxysomes, ribosomes.
In this glossary, definitions are given for the most commonly used terms for describing plants. |Aborted|an aborted organ is one that is not developed to the extent it should normally have| |Adpressed|erect, pressed closed to stem or other part of plant.| |Adventitious|roots springing from a stem whether aerial, underground or in water.| |Aerial|developed above the soil, such as aerial stems so called in contradistinction to underground stems developed below the soil.| |Alternate|attached to stem singly at different levels or nodes.| |Amplexicaul|base of leaf clasping the stem| |Androecium|collective name for the stamens| |Annual|plant that completes its life cycle within one year, therefore living not more than one year| |Anther|part of the stamen enlarged and containing the pollen, usually divided in two parts called anther-lobes| |Auricles|lateral lobes at base of leaf-blade| |Awn|prolongation, more or less narrow, at apex of a fruit| |Biennal|plant that completes its life cycle within two year, usually produces a short stem, leaves and roots during the first season, flowers and fruits during the second season and then dies| |Bract|leaf born near the flowers, usually at base of pedicel| |Bulb|swollen part formed most commonly by base of stem surrounded by thick scale-leaves or leaf-bases.| |Calyx|outermost envelope of flower made of sepals, usually green but sometimes looking like petals| |Calyx-Tube|tube formed by united sepals| |Capitulum|inflorescence of sessile flowers inserted side by side on a common receptacle formed by the enlarged apex of the flowering stem| |Head-Flowers|see capitulum| |Carpel|elementary female organ. In the simplest case, it is free, and not fused with the others ; it is then made up of: (i) an enlarged basal part or ovary, (ii) a more slender part above or style that finishes in (iii) a small viscous part or stigma on which pollen grains are deposited after pollination.| |Cauline|on an aerial stem| |Chamber|cell containing the pollen in the anther-lobes| |Locule|cell containing the ovules in an ovary| |Cilia|hairs in a row bordering any part of a plant| |Ciliate|bearing cilia| |Compound|(leaf) leaf-blade divided to midrib into separate parts called leaflets| |Connate|similar organs united round the stem or together| |Cordate|heart-shaped| |Corm|solid underground stem shortened vertically as in the crocus| |Corolla|corolla is composed of petals which are either free from one another or more or less joined together| |Dialypetalous|when petals are free from one another| |Dialysepalous|when sepals are free from one another| |Gamopetalous|when petals are more or less joined together| |Gamosepalous|when sepals are more or less joined together| |Corolla-Tube|tube formed by united petals| |Crenate|leaf-blade margin with rounded teeth| |Deciduous|falling early in the autumn| |Decumbent|when stem is prostrate but turns upwards at apex| |Decurrent|when the leaf limb is prolonged down the stem| |Dehiscent|opening to liberate pollen or seeds| |Indehiscent|not opening to liberate seeds| |Dentate|margin toothed| |Serrate| | |Didynamous|stamens 2 long, 2 short| |Dimorphic|having 2 different aspects, forms, shapes or structures| |Dioecious|male and female flowers born on different plants| |Entire|margin not lobed or toothed| |Envelope|floral envelope is a general term for calyx or corolla| |Epicalyx| supplementary sepals below ordinary sepals| |Escape|see garden escape| |Extrose|anthers opening and shedding pollen away from stigmas| |Filament| part of stamen bearing the anther| |Flower|collection of particular leaves terminating a stalk. The essential organs of the flower are the stamens and pistils. According to the authors, Gymnosperms are considered as flowering plants like Angiosperms.| |Fronds|the leaves of ferns| |Fruit|after fertilisation, ovary ripens into a fruit containing seeds (fertilised ovules)| |Garden Escape|uncultivated plant growing from seed of a cultivated one| |Glabrous|smooth; not hairy| |Glandular|hair with a rounded mass, often viscid or scented at their apex| |Glaucous|bluish or whitish green due to a waxy bloom on the surface| |Grooved|marked by longitudinal furrows| |Gynaecium|the pistil| |Hastate|auricles of leaf pointing more or less horizontally| |Hermaphrodite|stamens (male organs) and pistil (female organs) present in same flowers| |Hispid|covered with rather stiff hairs| |Hybrid|plant obtained from a seed produced in a pistil of one species which has received the pollen of another species| |Inflorescence|a flowering branch bearing a single flower or a collection of flowers sometimes separated only by bracts| |Introrse|anthers opening and shedding pollen towards stigmas| |Involucel|collection of bracts at base of an umbellule, or partial umbel, in a compound umbel| |Involucre|whorl or whorls of bracts at base of an umbellule or an umbel, or below one or several flowers| |Involute|rolled towards upper surface| |Irregular|flower in which a right and a left half can be distinguished, i.e. symmetrical in one plane, or, flower not exhibiting any symmetry| |Keel|the two more or less united anterior petals which together resemble the keel of a boat in flowers such pea flowers| |Labellum|petal resembling a lip and so differing considerably from the other petals of an Orchid| |Lamina|leaf-blade| |Lanceolate|about three times as long as broad, and tapering towards each end| |Leaf|leaf is always born on a stem, usually has a bud or branch in its axil. It is usually made of a blade or lamina and a petiole.| |Leaflets|the separate parts of a compound leaf-blade| |Ligulate|Asteraceae flowers with a flattened or strap-shaped corolla| |Lobes|more or less separate parts of the leaf-blade| |Membranous|thin, having a consistence somewhat resembling parchment| |Monoecious|male (staminate) and female (pistillate) flowers born on the same plant| |Naturalised|plant introduced by man in a country but continues to reproduce itself| |Nectary|structure secreting and exuding little drops of sweet liquid i.e. nectar, situated on petals, leaf-blade base, pistil base…| |Node|part of stem to which leaf base is attached. If the leaf sheathes the stem, as in grasses, the node is at the base of the sheath.| |Obtuse|apex more or less rounded| |Opposite|for leaves, when they are born in pairs at the same node ; for flowers, when 2 different perianth parts are on the same radius and are not alternate| |Ovary|part of a single carpel or fused carpels which encloses ovule or ovules| |Ovule|small rounded or oval bodies attached to the margin of the carpel and enclosed in the ovary. After fertilisation, ovule ripens into seed.| |Papilionaceous|corolla resembling a butterfly| |Pappus|tuft of hairs or ring of scales born on a fruit| |Pectinate|resembling a comb| |Pedicel|stalk terminating in a flower, and commonly called the flower-stalk| |Pedicellate|having a distinct pedicel| |Peduncle|the main flower-stalk, i.e. that part of the stem which bears the pedicels| |Peltate|leaf in which the stalk is attached to the under surface of the blade| |Perennial|plant living more than two seasons: trees, shrubs but also herbaceous plants with well-developed underground stems| |Perfect|flower having both stamens and pitil| |Perfoliate|blade of leaf completely surrounds stem| |Perianth|the 2 flower envelops together: calyx and corolla| |Persistent|existence prolonged beyond the normal term: for example persistent leaves do not fall in the autumn| |Petal|the innermost perianth envelop, usually well-coloured when pollination is made by animals and not wind| |Petiole| relatively narrow part below the leaf-blade, and commonly called leaf-stalked| |Petiolate|having a petiole| |Pinnate|compound leaf with leaflets in rows on either side of midrib| |Pistil|the part of flower formed by free or fused carpels and occupying the centre of the flower| |Pistillate|flower having a pistil but not stamens| |Pollen|dust-like grains formed in the anther of a stamen and which finally produce male gametes| |Prickle|sharply pointed structures born irregularly on the surface of a stem or other organ| |Raceme|a simple raceme is an inflorescence in which the flowers are distinctly stalked and born one above the other on a main flower-stalk or peduncle, the oldest ones being the closest to the inflorescence base. A compound inflorescence is an inflorescence of groups of flowers arranged in a raceme.| |Radical|leaves born on stem at or slightly below the ground level| |Receptacle|the upper part of the pedicel or peduncle on which the various parts of the flower are inserted| |Revolute|rolled towards under surface| |Root|one of the three primary organs of a plant (root, stem and leaves). It is distinguished from a stem in bearing neither leaves, nor scales, nor scars of fallen leaves. It is distinguished from a leaf in having neither a right nor a left side, nor an upper or a lower surface.| |Rootlet|branch of a root| |Rosette|leaves are in a rosette when they are number attached very closed together on the stem and spreading radially outwards. A rosette can be at a stem apex or at the ground level in acaulescent plants| |Sagittate|auricles of leaf pointing downwards| |Scales|leaves reduced in size and not performing usual functions; chaffy structures occurring on different parts of a plant; membranous bracts in many inforescences| |Seed|ovules in the ovary ripen to form seeds when ovary ripens to form the fruit| |Sepal|parts of the outermost envelope of flower, usually green but sometimes coloured| |Sessile|without a stalk| |Sheath|the expanded base of a leaf more or less surrounding or sheathing the stem thoughout a variable length| |Simple|leaf with a blade not separated into leaflets| |Sinuate|(leaf) margin bluntly and irregularly lobed| |Sorus|cluster of sporangia| |Spike|a simple spike is an inflorescence having all its flowers sessile and one above the other, the oldest ones being the closest to the inflorescence base. A compound spike has groups of flowers arranged in spikes| |Spikelet|see Poaceae| |Spine|leaf, stipule, or part of leaf modified into an elongated and pointed structure| |Sporangia|small sacs enclosing spores in Ferns and allied plants| |Spreading|diverging from the attachment point| |Spur|tubular or horn-shaped base of some sepals and petals| |Stamen|(androecium) organ forming pollen, the coloured dust which is deposited on the pistil if the ovules are to become seeds (if fertilisation happened). A stamen is genrally composed of a stalk or filament terminated by an enlarged part or anther. The anther contains the pollen and, and when ripe, opens to liberate it. The stamens are often free or detached quite to their base, and inserted to the receptacle as are sepals, petals and carpels. Often also they are united to other parts of the flower, either calyx or corolla. Flowers which have stamens but not pistil are called staminate flowers.| |Standard|upper or posterior petal in a papilionaceous fllower. In Pea flower, the standard overlaps the petals to the right and left which in turn overlap the two more or less united flower petals or keel| |Stem|one of the three primary organs of a plant (root, stem and leaves). It is distinguished from a root in bearing leaves or scales or scars of fallen leaves. It is distinguished from a leaf in having neither a right nor a left side, nor an upper or a lower surface.| |Stigma|the more or less viscid apex of a carpel, or of a pistil when carpels are united, often born on an elongated structure or style. The stigma retains on its surface pollen transferred from the stamens| |Stipules|parts of aleaf on the right and left of the base of the petiole just where the latter is attached to the stem. Many leaves have no stipules| |Striate|slightly grooved longitudinally| |Style|the more or less elongated structure bearing the stigma of a carpel. In some flowers, the style is very short or not developed| |Tendril|elongated and sensitive parts of a stem or a leaf, responding to the stimulus of contact by twining round or attaching themselves to support, and so enabling the plant to climb| |Thorn|branch modified to form a sharply pointed structure| |Trimorphic|anthers and stigmas at three different levels in the flowers of the same species| |Tuber|swollen part of a root or underground stem| |Tubular|flowers with a tubular corolla as in the Asteraceae| |Umbel| a simple umbel is an inflorescence with all flower pedicels equal in length and attached to the same level ; when present, bracts form an involucre at this level. A compound umbel is an umbel of umbels, partial umbels are also called umbellules with, when present, involucel at their base| |Umbellule|partial umbel of a compound umbel| |Valve|one of the parts into which fruit wall splits when mature| |Veins|(of the leaf) veins are the leaf conducting tissue, the median vein is the midrib| |Venation|arrangement of veins in a leaf| |Whorled|(leaves) leaves are three or more born at the same node or level on the stem; also called verticillate leaves| |Wild|(plant) a plant growing and reproducing itself naturally, i.e. not cultivated or planted| |Wing|(flower) one of two lateral petals in papilionaceous flowers; (other plant structure) thing and flat projecting part of a plant structure|