Glossary - general

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Baccate – berry-like

Bacterial nodules (of leaves) – dark inclusions formed of bacteria (e.g. in Pavetta and some Psychotria); bacteriodomatia

Baculum (pl. bacula) (of pollen grains) – see Columella

Balanoform hairs – (Poaceae) microhairs with a broad, blunt apex

Balsamiferous – balsam (resin)producing

Banded parenchyma – parenchyma bands may be mainly independent of the vessels (apotracheal), definitely associated with the vessels (paratracheal) or both; bands may be wavy, diagonal, straight, continuous, or discontinuous

Barbate – bearded; with a tuft of long hairs

Barbed – with rigid points or bristles pointing backwards

Barbellate – shortly barbed; in Asteraceae used of spreading or upward-pointing pappus hairs which have free cell apices shorter than the diameter of the main axis

Bark – rough outer layer of stem in a woody plant

Barrel-shaped (of three-dimensional shapes) – resembling a barrel, i.e. shortly and broadly cylindrical, but tapering slightly at base and apex

Basal – attached at or near the base; proximal

Basal cell – the micropylar cell of the suspensor of the proembryo, sometimes with a haustorial function; the micropylar cell which is produced by the first division of the zygote and which divides to form the suspensor (the chalazal apical cell produces the main part of the embryo)

Basal placentation – the placenta is situated at the base of the ovary

Base – usually the point of attachment of any organ

Basic type of anther wall formation – all the cells in the secondary parietal layers divide once periclinally, forming four new layers which differentiate, from outside to inside, into the endothecium, the two middle layers and the tapetum

Basifixed anther – the anther is attached by its base

Basilateral – situated at the base and on one or more sides

Basipetal (ous) – developing in the direction of the base (away from the apex) – Opposite: acropetal

Basipetally developed venation – venation developing toward the base

Beak – a long slender projection, like the beak of a bird (e.g. persistent style base on fruit); rostellum

Beaked – with a beak, with a long slender projection; rostrate

Bearded (of a three-dimensional object) – with a tuft of long hairs on one part

Begonioid leaf tooth – with a translucent apical group of densely packed cells; one lateral vein strengthened at the expense of the apical and the second lateral vein

Berry – a juicy indehiscent fruit with one to several seeds immersed in pulp, the seeds lacking endocarp

Bialate – with two wings

Biarticulate – jointed in two places

Biauriculate leaf sheath – with two ear-like appendages (auricles)

Bibracteolate – with two floral prophylls (bracteoles)

Bicapitate – with two heads

Bicarinate stipules or leaf – with two keels

Bicarunculate – with two caruncles

Bicollateral vascular bundle – conjoint vascular bundle consisting of a single set of xylem, two sets of cambium and two sets of phloem; the phloem is present both external and internal to the xylem; the bicollateral vascular bundle is always open

Biconvex – domed on two sides; lenticular

Bicrenate – doubly crenate, with scalloped edges, the lobes of which are again scalloped

Bicyclic – consisting of two whorls of entities

Bicyclic perianth – consisting of two whorls of perianth parts (tepals), usually outer whorl of sepals and inner whorl of petals

Bidentate – with two teeth

Biennial – taking two years from seedling stage to maturity, seed-set and death

Bifacial – horizontally flattened shape; also used in sense of two surfaces different in texture or colour

Bifarious – distichous

Bifid – divided at the tip in two (usually equal) parts by a median cleft

Biflabellate leaves – in two opposite fans (in Amaryllidaceae often with the term biflagellate)

Bifoliate – with two leaves

Biforine – a cell capable of expelling calciumoxalate raphides

Bifurcate – forked or divided into two sharp branches or prongs

Bifurcating – forking, dividing into two sharp branches or prong

Biglandular – with two glands

Biglobular stigma – consisting of two globose parts

Bilabiate – two-lipped, as when the parts of a calyx or corolla form two clearly separated projections, usually an upper and a lower, as in Lamiaceae, or a corolla with usually two smaller adaxial lobes and an abaxial lumina with three lobes at the apex, as in Asteraceae

Bilamellate placenta – (i.a. Begonia) two-branched (bilobate) placenta

Bilaterally symmetrical – see Zygomorphic

Bilobate – with two lobes

Bilocular – with two compartments, usually of a two-celled ovary

Binate – divided in two, or nearly so

Binucleate tapetal cell – tapetum cell containing two nuclei

Binucleate pollen grain – pollen grain containing two nuclei (cells), although the number of nuclei may vary among pollen grains of the same individual; binucleate condition is often associated with a sporophytic incompatibility system

Biparous – bearing two (e.g. flowers)

Bipartite – divided in two parts at the apex

Bipinnate – doubly pinnae, i.e. the rachis bearing first-order axes which bear the leaflets; when the primary divisions of a pinnate leaf are themselved pinnately compound

Biramous – with two branches

Bisegmented – partly divided in two

Biseriate – in two series or whorls

Biseriate wood ray – with two rows of ray cells

Biserrate leaf margin – serrate, but with alternating teeth of two different sizes; or when large serrations are themselves serrate

Bisexual – having both sexes in the same flower, or in the same inflorescence

Bisporangiate – see Disporangiate

Bisporic – see Disporic

Bistomal micropyle – the micropyle is formed from two integuments

Bisulcate pollen grain – with two grooves (sulci)

Bisymmetrical – disymmetrical; with two planes of symmetry

Bisyncolporate pollen grain – with two compound colpi the ends of which anastomose at the pole(s)

Bitegmic ovule – megasporangium surrounded by two integuments

Biternate – compound ternate, the ternate divisions themselves divided in threes

Bithecate anther – with two thecae or locules – Opposite: unithecate

Bivalved – with two valves

Biventricose – swollen or inflated on two sides

Bixoid chalazal region – (some clades of Malvales) the exotegmen invaginates the chalazal region, into which a plug of hypostase tissue, with core and annulus, fits; the outer hypostase forms a core which is called the ‘bixoid chalazal region’

Blade – expanded part of leaf or petal

Bloom – fragile, powdery surface layer (i.a. the waxy bloom of a plum or a banana bract)

Blotch – irregular spot of colour

Bole (of tree) – the part of the trunk below the lowermost branches; the unbranched part of the trunk

Bordered pit – a pit possessing an extension of the secondary cell wall arching over part of the pit cavity

Boss – knob or knob-shaped protuberance (usually on root, trunk or branch)

Bostryx – spiral cymose inflorescence in the shape of a ringlet, i.e. in three dimensions, with the lateral branches developing from the same side and in the same plane as the coil

Botryoid – a closed raceme (with terminal flower)

Botryum – an open raceme (without terminal flower)

Botuliform – sausage-shaped

Brachyblast – short shoot of limited growth (e.g. a spur shoot, usually borne on a long main axis)

Brachycolpate pollen grain – with short colpus/colpi

Brachyparacytic stomata – monocyclic stomata with four or five subsidiary cells, two of which are distinct, parallel to the stoma and smaller in size as compared to the remaining subsidiary cells, the poles being exposed to indistinct subsidiary cells; paracytic stomata with two subsidiary cells parallel to the guard cells but not entirely enveloping them

Brachysclereid – stone cell; a fairly short, isodiametric sclerenchyma cell (sclereid)

Brachystylous (in heterstylous flowers) – thrum-eyed; the short-styled morph – Opposite: dolichostylous

Bract – inflorescence pherophyll; a modified and specialized leaf in the inflorescence, often small and subtending partial peduncles, pedicels or flowers

Bracteate – subtended by, or beset with bracts

Bracteolate – subtended by, or beset with floral prophylls (bracteoles)

Bracteole – floral prophyll, floral pherophyll, prophyll of flower-bearing shoot; a secondary bract, usually smaller than the ordinary bracts and always borne above them; a small modified leaf (or pair of modified leaves) borne just below the flower

Breathing root – specialized roots growing upwards from horizontal roots in mangrove or swamp plants, exposed at low tide; usually with lenticels allowing gas exchange; pneumatophore

Brevicolpate pollen grain – see Brachycolpate pollen grain

Bristle – a strong and stiff cylindrical emergence

Bristly – bearing stiff strong hairs or bristles

Brochidodromous venation – with loop-veined venation; main veins emerging from the midrib at regular intervals, at the margin turning towards the apex and looping to join the next vein upwards; with a single primary vein, the secondary veins not terminating at the margin but joined together in a series of prominent upward arches or marginal loops on each side of the primary vein

Bucciniform – (Balsaminaceae) shaped like the end of a trumpet

Bud – a meristem (apical or lateral) in early development or resting stages with its protective coverings; immature shoot, covered with scales

Bulb – underground storage organ; the bud(s) enclosed by fleshy scale leaves and/or leaf bases

Bulbiform – shaped like a bulb, broadly ovoid and tapering distally to a point

Bulbil – a small, usually axillary bulb (i.a. in the axil of a leaf) capable of developing into a new plant

Bulbiliferous – producing bulbils

Bullate – with the surface of the leaf raised in blisters or puckers between the veins

Bulliform – bubble-like

Bulliform cell – large thin-walled cell on the adaxial epidermis, that help cause curling and uncurling of the lamina as its turgor changes

Bundle sheath – cylinder of cells surrounding a vascular bundle

Bundle sheath cells – a layer of cells in plant leaves and stems which forms a sheath around the vascular bundles; in C4 plants the bundle sheath cells contain chloroplasts and are the site of the Calvin cycle; the bundle sheath is surrounded by palisade mesophyll cells, in which the initial fixation of CO2 into malic acid (a 4-carbon compound) takes place

Burr – (1) rough, prickly envelope of a fruit, formed of cohering prickly bracts, accrescent calyx or pericarp; (2) woody swelling, usually at the base of a trunk, associated with epicormic shoots

Buttress – mechanical supporting system at the base of a tree, usually a woody fin

Buttressed – of the lower trunk of a tree, with buttresses