Glossary - general
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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