Glossary - general


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Caducous – falling off soon after formation, not persistent

Caecum (of megagametophyte) – a pouch-shaped extension (sometimes in the chalazal part) of the megagametophyte, probably functioning in the expansion of the megagametophyte and in the haustorial nutrient absorption; a prolongation of the embryo

Caespitose – growing in tight groups, the bases of the individual plants touching

Calcarate – with a spur, spurred

Calceiform – slipper- or shoe-shaped

Calciumoxalate crystals – see Crystal sand, Druse, Raphide, Rhomboid crystal, Styloid; druses are the most frequent type of calciumoxalate crystals

Callose – polysaccharide formed on injury of parenchymatous tissue and also present in e.g. pollen tubes

Callus (pl. calli) – (1) a hard protuberance; (2) wound-covering tissue; (3) (Poaceae) a horny prolongation at the base of the floret or spikelet; (4) thickenings, e.g. on the calyx of some Oxalidaceae, or on one of the lips of some Orchidaceae

Calybium (pl. calybia) – (Fagaceae) the fruit (nut) which is partially or entirely surrounded by the cupule

Calyciform – cup-shaped, or resembling a calyx

Calyculate – having bracts around the calyx, or with an involucre resembling an outer calyx

Calyculus – in a flower of Orchidaceae a small cup or circle of bractlike structures outside of the sepals; in some Asteraceae a subsidiary circle of small phyllaries outside a row of uniseriate phyllaries

Calymmate pollen tetrad – with tectum partly continuous between adjacent pollen grains in the tetrad

Calyptra – cap- or lid-like covering of flowers or fruits (i.a. in Myrtaceae)

Calyptrate – cap-like; e.g. of petals, when they fall off as a coherent unit

Calyx (pl. calyces) – the outermost whorl of floral organs, often divided into sepals

Calyx tube – the tube (as distinct from the limb) in a gamosepalous calyx; sometimes used for hypanthium

Cambium – a meristem responsible for secondary lateral growth and production of xylem inside and phloem outside

Campanulate – bell-shaped; with a tube about as long as wide, and a flaring limb

Camptodromous venation – the secondary veins curve towards the margin of the leaf, but do not form loops; may be either eucamptodromous or brochidodromous

Campyloanatropous ovule – intermediary between campylotropous and anatropous ovule

Campylodromous venation – with several primary veins or their branches diverging at or close to a single point and running in strongly developed, basally recurved arches which converge toward the apex, either reaching it or not

Campylotropous ovule – ovule with embryo-sac curved and at right angles to its stalk

Canaliculate – with a longitudinal channel or groove; channelled

Cancellate – with the appearance of a lattice

Candelabra branching – with branches coming from one point, curving upwards and reaching more or less the same level

Canescent (of indument) – more or less grey or hoary, or becoming so

Canoe-shaped – shaped like a canoe, i.e. shortly canaliculated, but with the ends swept up and not grooved (e.g. of pyrenes in some Rubiaceae)

Cap – convex, removable covering of a part

Capillary – very slender, hair-like

Capilliform – very slender, hair-like

Capitate – 1) head-like; like the head of a pin (i.a. for a stigma); 2) collected into heads of flowers ( as in Asteraceae)

Capitellate – diminutive of capitate

Capitulum (pl. capitula) – cephalium; an open head (without terminal flower); a compact cluster of more or less sessile flowers; the capitulum may be surrounded by specialized bracts, the involucre

Capsule – a dry fruit composed of a single or two or more connate carpels, either splitting into valves, or opening by slits or pores

Carina – 1) keel, long narrow ridge over the length of a flat or curved surface; 2) keel, formed by the two lower petals in papilionoid flowers (i.a. in Fabaceae and Polygalaceae)

Carinal stigma or stigmatic lobes – opposite the centre of the carpels

Carnivorous – plants deriving (part of) their nutrition from animals they have captured

Carnose – fleshy

Carpel – the basic unit of the female sexual organ; one of the cells or locules of the syncarpous ovary, containing the ovules; the megasporophyll

Carpellate – with carpel(s) – Opposite: acarpellate

Carpidium – aggregation of follicles

Carpodium – the modified gynoecium in the sterile flowers of Typha, usually club-shaped

Carpophore – a prolongation of the receptacle or floral axis bearing the carpels or ovary (e.g. in Ranunculaceae)

Carpopodium – (Asteraceae) a basal callus to the achene

Cartilaginous – hard and tough, but slightly bendy

Carunculus – caruncle; an outgrowth of the outer seed integument, near the hilum; usually small and fleshy, and associated with animal dispersal; also called a strophiolus (strophiole), although a strophiolus is an outgrowth from the raphe, while the carunculus is next to the micropyle

Carunculate – with a carunculus

Caryophyllad embryogenesis – the basal cell does not divide or it may divide only once and both the cells undergo considerable enlargement; instead, the apical cell shows the organization of a second tetrad of all the three series; the further course of the embryogenesis varies according to the plant group in question

Caryopsis – (type of achene) the nutlike fruit in Poaceae, with seed attached to pericarp

Casparian strip – a band of cell wall material, suberin, which is deposited on the transverse and radial walls of the endodermis and is chemically different from the remaining cell wall; the casparian strip (casparian thickenings) prevents the passive flow of substances into the stele

Cataphyll – scale leaf, scale-like leaf

Cataulcerate pollen grain – with ulcus/ulci proximal on the pollen grain

Catenate – linked as in a chain

Catkin – see Ament(um)

Caudate – abruptly ending in a long tail-like tip or appendage; very protracted, excessively acuminate

Caudex – classically, the axis of a plant, consisting of stem and root; latterly, especially in Euphorbiaceae used as an enlarged storage organ at soil level, composed of the swollen stem, or root, or both

Caudicula, caudicle – (1) (Orchidaceae) a narrow stalk connecting the pollen masses, which is derived from inside the anther; (2) (Euphorbiaceae) small stem at or about ground level, arising from rootstock, from which annual stems arise; (3) in a flower of Orchidaceae, a slender, mealy or elastic extension of the pollinium, or a mealy portion at one end of the pollinium; produced within the anther

Caulescent – with an evident stem above ground

Cauliflorous – with flowers and fruits on the stem or the trunk

Cauline – arising from, or inserted on the stem

Caustic – burning in taste or on the skin

Caveate tectum (of pollen grains) – with a cavity between two layers of the exine extending to the colpus margin where the layers meet

Cavity – small, narrow hollow

Cell – (1) the caviaty or cavities of an ovary or fruit containing the ovules or seeds; (2) the pollen sac of an anther, an anther lobe or theca

Cell plate – a structure in the plane of cell division during cytokinesis which is composed of fused Golgi-derived and endosomal vesicles containing material for the cell wall and the cell membrane

Cellular embryo – embryo consisting of cells – Opposite: coenocytic embryo

Cellular endosperm – the cell wall formation coincides with the nuclear divisions

Central cell – the largest cell of the megagametophyte; the central cell contains two polar nuclei

Central placentation – free-central placentation, columnar placentation; the placentas are situated in a central column within a non-sectioned syncarpous ovary; the ovules are present along the central column of the lysicarpous gynoecium

Centrifixed anther – (in monocotyledons) the anther is attached by its centre, the filament apex being inserted into a hollow in the anther

Centrifugal staminal development – androecium developing from the floral centre outwards

Centrifugal vascular tissue – the older protoxylem vessel elements are situated towards the medulla and the younger metaxylem vessel elements away from the medulla (endarch xylem); frequent in leaves and stems/branches

Centripetal staminal development – androecium developing from the outside of the flower towards the floral centre

Centripetal vascular tissue – the younger metaxylem vessel elements are situated towards the medulla and the older protoxylem vessel elements away from the medulla (exarch xylem); frequent in the root

Centroscopic – facing the centre, e.g. of grooves in the phalanges of Pandanus inflorescences

Cephalioid – a closed head (with terminal flower)

Cephalium – see Capitulum

Chaffy – like small papery scales

Chalaza – part of ovule where the ovule body joins the ovule envelope

Chalazal end – the base of the nucellus, opposite the apex of the cotyledon(s)

Chalazogamy – the pollen tube enters through the tissue of the ovary wall into the placenta, penetrating into the ovule by the chalaza, subsequently growing toward the micropylar end through one of the elongated sterile macrospores coming into contact with the fertile macrospore without entering it; the sperm cell is extruded into the macrospore entering the oosphere from below

Chalazosperm – perisperm-like nutritive tissue developed in the chalazal region (not from subdermal megasporangial tissue); sometimes replacing the endosperm

Chambered pith (medulla) – see Lamellate medulla

Chamaephytes – plants with renewable buds exposed at ground level

Channelled – with a groove running along its length

Chartaceous – thin and stiff, like paper

Chasmogamous – pollinated when flowers are open – Opposite: cleistogamous

Chenopodiad embryogenesis – a linear tetrad of the proembryo is formed; the basal cell also contributes to the hypocotyledonary region; an epiphysis is usually not produced

Chloranthoid leaf tooth – with persistent opaque swollen cucullate structure, into which lateral veins are running, central vein joined by branches from above and below then running into tooth apex

Chlorenchyma – photosynthetic tissue in leaf or stem; the cells of the chlorenchyma contain chloroplasts

Cicatricose – scarred

Cilia (sing. cilium) – marginal hairs

Ciliate – bearing a fringe of hairs along the margin

Ciliolate – fringed with very small hairs

Cincinnal branch – lateral branches arising alternately on opposite sides of the false axis

Cincinnate – in the shape of a cincinnus

Cincinnus – scorpioid cyme; inflorescence with flowers appearing alternately to the right and left of one side of the sympodial axis

Circinate, circinnate – coiled inwards upon itself with its apex innermost (hooks or tendrils of some climbers, leaves of, i.a., Drosera)

Circinotropous ovule – (Cactaceae) with circinate and usually long and curled funicle

Circumferential – around the edge of a circle

Circumflexed – bent round

Circumscissile – opening (dehiscing) or falling off as if cut off along a transverse line around the equator, the upper part coming off like a lid (e.g. pyxis, pyxidium)

Cirrhose – with tendrils

Cirriform – resembling a tendril

Cirrus – (Arecaceae) barbed whip tip extension of leaf midrib

Cladode – single node/internode of stem or branch flattened and expanded to serve the functions of a leaf

Cladodromous venation – with a single primary vein, the secondary veins not terminating at the margin and freely ramified towards it

Clambering – climbing without the aid of tendrils or twining stems

Clasping leaf base – almost surrounding, touching the stem closely on two sides

Clathrate – pierced with holes, like a lattice

Clavate – club-shaped; thickened towards the upper end

Clavate tectum (of pollen grains) – with club-shaped elements (clavae) of the sexine/ectexine which are taller than 1 µm and have a diameter narrower than the height and thicker at the apex than at the base

Clavellate – diminutive of clavate: like a minute club, thickened at the upper end

Clavuncula – clavuncle; (Apocynaceae) an enlarged stigma of which the sides and lower surface are the receptive zone, usually coherent with anthers

Claw – the narrow proximal part of a flat round organ (e.g. of a petal)

Clawed – with a very narrow part near the base, but more distally with an expanded blade

Cleavage polyembryony – several or numerous embryos develop in each ovule due to subdivision and separation of a number of embryos from a single proembryo

Cleft – divided almost to the middle

Cleistogamous – when self-fertilization occurs within the unopened flower; this type of flower is usually smaller than the chasmogamous flower, but it may be facultative with normal flowers as well – Opposite: chasmogamous

Climber – a plant (i.a. Hedera, Parthenocissus) that grows upwards by attaching itself to other structures which it uses as supports; a scrambler does not attach itself to its supports

Climbing root – short negatively phototropic adventitious root which develops from the stems of some climbing plants and serve to attach the plant to its supporting substrate; mucilaginous substances are secreted from the root apex

Clinandrium – (Orchidaceae) in an orchid flower the anther bed; that portion of the column under, or surrounding, the anther

Clockwise (of growing or overlapping) – when seen from above, following the hands of a clock

Closed vascular bundle – see Collateral vascular bundle

Cluster – a tight group

Coating – a close, dense thin layer formed on the surface of an organ either by disintegration of part of that organ or by exudates

Coaxillary/co-axillary – running with the main axis but separate from it

Coccus (pl. cocci) – one of the separate parts of a lobed capsule (e.g. in Euphorbiaceae)

Cochleariform – spoon-shaped

Cochlear – spiral, coiled like the shell of a smail

Cochlear aestivation, cochleate aestivation – imbricate aestivation in which one sepal/petal with both its edges is positioned outside those of the adjacent sepals/petals, one sepal/petal with the two edges are both positioned inside and the other sepals/petals with one edge positioned outside and the other inside

Coenocytic – the nuclei of the cells divide, but not the cytoplasm, which results in a cell containing several or many nuclei

Coenocytic embryo – the zygote undergoes synchronous free-nuclear divisions (nuclei peripherally arranged) forming a coenocytic primary stage of the development

Coherent/cohering – attached to each other (among similar organs)

Coiled – rolled up, like a spring, upon itself

Coleoptile – a tubular structure developed at the apex of a closed cotyledonary sheath and surrounding the plumule of a monocot embryo or seedling

Coleorhiza – a tissue initially completely surrounding and subsequently forming a collar around the base of shoot-born roots of a young seedling axis of some monocotyledons

Collar – the base of the hypocotyl, sometimes marked by an external line or a swollen area and/or bearing collar rhizoids adjoining a hypocotyl in a monocotyledon embryo or seedling

Collar rhizoids – see Collar

Collateral – (1) cotyledons equal in seed (as opposed to superposed); (2) bud lateal to axillary bud; (3) (of seeds, Annonaceae) side by side

Collateral vascular bundle – conjoint vascular bundle consisting of a single set of xylem and a single set of phloem; the phloem is present on one side of the xylem only (usually internal to the phloem); the collateral vascular bundle may be open or closed

Collenchyma – tissue with elongate parenchyma-like cells having thick primary walls and retaining their cytoplasm; the collenchyma is responsible for structural support

Colleter – multicellular glandular hair-like (usually non-vascularized) structure associated with petioles, stipules and/or sepals; colleters secrete resin and/or mucilage

Colliculate – covered in small rounded protuberances; minutely hilly

Colliculate pollen grain – beset with tiny rounded elevated processes (colliculae)

Colpate pollen grain – possessing a wall with more or less linear apertures

Colporate pollen grain – possessing a wall with compound apertures: linear in the outer wall, rounded in the inner wall

Colubrinoid – snake-like

Columella (of fruit) – persistent central axis surrounded by the fruit locules

Columella (of pollen grain) – rod-like element of the sexine/ectexine, which supports a tectum or a caput (expanded apex of a columella)

Columellar infratectum – the layer beneath the tectum provided with columellae

Column (1) (Orchidaceae) the adnate styles and stamens forming a solid central body; (2) the tube of connate anther filaments (e.g. in Malvaceae); (3) in Poaceae, the lower twisted part of the awn

Column foot (of flower) – (Orchidaceae) a ventral extension at the base of the floral column; the lip is attached at its apex

Columnar – in the form of a column or pillar

Columnar placentation – see Central placentation

Coma – a tuft of long hairs at one or both ends of a seed

Commissural – area along which two structures are fused

Commissural stigma or stigmatic lobes – each stigmatic lobe being common to two adjacent carpels; one lobe-half belongs to the first carpel and the other lobe-half belongs to the second carpel

Commissural veins – small veins connecting the larger parallel veins, especially in monocotyledons

Commissure – the place of joining, i.a. the faces of joining carpels

Comose – bearing a tuft, or several tufts, of hair (coma)

Compitum – a common inner space resulting from the postgenital connation (fusion) of the stylar (occasionally only the stigmatic) part of the carpels in a syncarpous gynoecium; the pollen tube transmitting tissues of the carpels are interconnected in the compitum; a tract of transmission tissue in the gynoecium which is common to all the carpels of the one flower and that allows pollen landing on any one stigma or part of a stigma to fertilize ovule in any carpel (intragynoecial compitum); a tissue allowing pollen tubes to fertilize any ovule independently of where the pollen grains land on the stigma, or, if the style is branched, independently of on which stigma they land; completely synascidiate carpels have no intragynoecial compitum; a compitum may develop through post-genital connation of the styles in taxa where the carpels are otherwise free; an extragynoecial compitum occurs in some taxa with free carpels (i.a. some Nymphaeales and Laurales), where the carpels are in contact by secretions of the stigmas

Complanate – flattened

Complicate – folded upon itself

Compound – (1) the opposite of simple; composed of several similar parts; (2) of an inflorescence, where there are two orders of branching, i.e. first order and second order; (3) in fruits, derived from more than one flower

Compound leaf – leaflets arising from separate primordia along the main axis of the leaf

Compressed – flattened (especially laterally)

Compressed-trigonous – three-sided, but distinctly flattened and thus appearing to be two-sided

Compression wood – reaction wood in softwood trees (e.g. conifers); formed below (underneath) the affected (down-bent) part thus pushing it up; compression wood is rich in lignin resulting in very hard and brittle wood

Concentric vascular bundle – one vascular tissue surrounds the other hence appearing in cross-section to be concentrically arranged; phloem and xylem appear in the same vascular bundle and surround one another; in an amphivasal (leptocentric) bundle the phloem is situated in the centre and surrounded by the xylem; in an amphicribal (hadrocentric) bundle the xylem is situated in the centre and surrounded by the phloem

Concolorous (of different sides of a leaf) – of one and the same colour – Opposite: discolorous

Concrescent – growing together

Condensed inflorescence – dense

Conduplicate – folded together longitudinally with the upper surfaces facing each other, each leaf clasping those next to it inside the fold – Opposite: reduplicate

Conduplicate carpel – folded together along the midvein, with the flat sides facing each other

Conduplicate ptyxis – folded longitudinally along the midvein, the adaxial surface being within; lamina folded once adaxially along the midvein; leaflets of compound leaves usually have a conduplicate ptyxis

Condyle – placental outgrowth or invagination

Conferted leaves – closely packed or crowded together

Confluent – coming together and merging

Confluent axial parenchyma – a paratracheal parenchyma in which vessels and vessel groups are situated in tangential parenchymatic bands; coalescing vasicentric or aliform parenchyma surrounding or to one side of two or more vessels, and often forming irregular bands

Confocal – used for two main veins both emerging at the base of the leaf

Congenital occlusion (of carpel) – fusion taking place at the same time as their differentiation

Congested – densely crowded

Congested leaf tooth – densely packed

Conglomerate – clustered

Conglutinate – as if glued together

Conjugate – coupled, connected

Connate – (1) united, used when structures or organs of the same kind are united margin to margin (e.g. petals connate); (2) (of leaves) where a pair are united at base

Connective – the part of a stamen between and connecting the anther cells, distinct from the filament; sometimes called the filament extension between the thecae

Connivent – two or more parts which are separated at the base but coming together (but not united) distally

Conoid(al) – cone-shaped

Constricted – abruptly narrowed

Contiguous – without an interruption; adjacent and touching

Continuous vascular cylinder – not abrupted, such as in the stem of a woody plant

Contorted aestivation – imbricate aestivation in which each sepal/petal overlaps its neighbour on one side, and is overlapped by its neighbour on the other side

Contortiplicate aestivation – an imbricate aestivation in which each sepal/petal has one edge overlapping the adjacent sepal/petal, although the calyx/corolla is connate

Contracted inflorescences – when narrow and dense

Contractile root – a thickened (specialized) root at the base of a bulb, corm, leaf-rosette etc., which is able to shrink vertically under dry conditions in order to keep the plant at a suitable level in the ground

Contraligule – (Cyperaceae) membranous, ligule-like structure at the apex of the leaf sheath on the side of the culm facing away from the lamina

Convolute – rolled from the sides with one side folded around the other

Convolute aestivation – see Contorted aestivation

Convolute ptyxis – rolled from the sides with one side folded around the other; each leaf with one half outside and the other inside

Coppice shoot – news branches arising from cut-back trunk or from the lower trunk (often with foliage different from normal foliage)

Cordate – of the base of a leaf, deeply notched so the whole base has a slight heart-shape; sometimes used for the shape of the whole leaf, which is then ovate with a notched base and an acute apex

Cordiform – shaped like a heart in two or three dimensions

Coriaceous – leathery, tough

Cork cambium – see Phellogen

Corky – with the consistence of cork, a protective, elastic tissue impervious to water

Corm – short underground swollen stem, a storage stem

Cormlet – diminutive of corm; a solid, bulb-like stem, usually underground

Corniculate – bearing a little horn

Corolla – the second whorl of floral organs, inside or above the calyx and outside the stamens, consisting of free petals or of a joined tube and petal lobes

Corona – series of appendages on the corolla or on the back of the stamens, or at the junction of the corolla tube and the corolla lobes; often united in a ring (i.a. in Passifloraceae)

Coroniform – crown-shaped

Corpus (of root apex) – the inner layers which divide anticlinally or periclinally

Corpusculum – (Asclepiadoideae) organ linking translator arms (and pollinia) in a pollinarium

Corrugated – wrinkled regularly and longitudinally

Cortex – the tissue, including the endodermis, between the epidermis and the stele in a stem or root; consisting mainly of ground parenchyma and often with collenchyma and sclerenchyma cells (sometimes chlorenchyma); the cortex is important as, e.g., storage tissue

Cortical – of cortex or bark

Cortical vascular tissue – vascular bundles present in the cortex

Corticate – with a cortex or bark

Corymb, corymbose inflorescence – a more or less flat-tooped, racemose (indeterminate) inflorescence in which the branches or the pedicels start from different points but all reach to more or less the same level

Corymbiform – shaped like a corymb

Costa (pl. costae) – rib, often of a leaf or pinna; when single, the midrib

Costapalmate leaf – (Arecaceae) a basically palmate leaf in which the petiole extends into the lamina as a well-defined axis – the costa – which effectively divides the lamina in two

Cotyledon – a leaf produced at the first node of an embryo/seedling; in a monocotyledon seedling the cotyledon is usually exposed and photosynthetic in its lower part (morphologically distinct areas may be photosynthetic), whereas at least the apex remains enclosed by the seed coat and/or the pericarp and is absorbtive

Cotyledonary sheath – part of the hypophyll which surrounds the cotyledonary node of a monocotyledon seedling, protecting the plumule

Cotyledon hyperphyll – see Hyperphyll

Coumarin – aromatic compound smelling of freshly cut grass

Counter palisade – a layer of strongly thickened cells, which is present in the hilum on each side of the hilum fissure and compensate for variations in the relative air humidity outside

Craspedodromous venation – with the nerves proceeding directly to the leaf margin; mixed craspedodromous venation has a single primary vein, some of the secondary veins terminating at the margin and an approximately equal number otherwise; simple craspedodromous venation has a single primary vein, all of the secondary veins and their branches terminating at the margin

Crassinucellar ovule, crassinucellate ovule – with a thick megasporangium, with one or more hypodermal cell layers outside the meiocyte, up to the time of megagametophyte formation; a single archesporial cell is cut off periclinally by a parietal cell, subsequently divides again, and thus forms several layers of megasporangium – Opposite: tenuinucellar

Crassitegillate exine (of pollen grains) – with a thick tectum

Crateriform – shaped like a cup

Crateriform nectary – cup-shaped nectary

Creeper – plant with stems running along the ground and rooting at intervals

Crenate margin – notched with regular rounded symmetrical teeth

Crenellate(d) – with alternating projections and indentations, with more or less right angles between the two

Crenulate margin – with small crenate teeth

Crescentic – curved and thinner at either end than in the middle; shaped like a young moon

Crest – an elevated, irregular ridge

Crested – with an elevated, irregular ridge

Crevices – narrow fissures or splits in bark (or rock)

Crimped – pleated

Crispate margin – curled, crisped

Cristarque cell – sclereid, at maturity dead cell with the lignin deposited excentrically in a U-shaped cell wall, also containing a calcium oxalate druse or crystals

Cristate – with a crest, a narrow band of stiff hairs or a narrow ridge

Cross layer (of seed)

Crown – (Balsaminaceae) the part of the stem at the surface of the ground

Crown shaft – (Arecaceae) a column of leaf sheaths tightly enclosing the developing leaves, forming a pseudostem at the tip of the stem

Crozier-shaped – shaped like a bishop’s crozier, i.e. with the apex coiled in one plane, like an unfolding fern frond

Cruciform – shaped like a cross

Crumpled aestivation – the petals are crumpled in bud

Crustaceous – of brittle texture

Cryptic – not obvious, hidden

Cryptocotylar germination – when the cotyledons are hidden non-photosynthetic; cryptocotylar seedlings have non-photosynthetic cotyledons that remain enclosed by the seed coat and/or the pericarp during germination

Cryptotetrad – see Pseudomonad

Crystal sand – a microcrystalline form of crystalline inclusions (usually calciumoxalate), which consist of separate minute tetrahedral prisms

Cuboid, cuboidal – with the shape of a cuboid, i.e. a solid figure bounded by six faces each of which being a rectangle

Cucullate – hooded (used especially for small plant parts)

Cucurbitoid leaf tooth – with a translucent apical group of densely packed cells; the two lateral veins fusing or connivent with the apical vein

Cuff – (Poaceae) the sleeve-shaped part where lower glume margins almost meet

Culm – aerial stem, present in, i.a., Poaceae, Restionaceae and Cyperaceae

Cuneate base – tapering gradually, wedge-shaped

Cuneate protein inclusions – wedge-shaped protein crystalloids of the monocotyledon type of sieve element plastids

Cuneiform – wedge-shaped, attached by the narrow end

Cunonioid leaf tooth – with the principal vein branching below the tooth, one branch proceeding to the sinus or towards the tooth above, the second vein proceeding along the upper edge of the tooth to the small glandular (non-spherical, not torus-shaped) apex

Cupular – cup-shaped

Cupulate – (1) bearing a cupule; (2) cup-shaped with more or less truncate edge, not lobed

Cupule – cup-like structure at the base of fruits, formed by the dry, enlarged floral envelope (bracts and inflorescence base, etc.)

Cupuliform – cup-shaped

Curved ptyxis – the leaf surface with the margins broadly curved in an adaxial direction (adaxially concave)

Curvipalmate venation – palmate venation with curved veins (nerves)

Cushion (of habit) – many plants growing close together, forming a dense rounded mass

Cusp – sharp, rigid point

Cuspidate – abruptly tipped with a sharp rigid point

Cuticle – layer on the outer walls of the epidermis composed of cutin, a fatty, water-repelling material

Cyanogenic glycosides – chemical compounds producing HCN

Cyathiform – shaped like a drinking cup

Cyathium (pl. cyathia) – (Euphorbiaceae) a thyrsoid with the flowers inserted on a cup-shaped involucre; the central female inflorescence is a female flower consisting of a pistil formed by three connate carpels; the male flowers are arranged in five scorpioid cymes (cincinni) surrounding the female flower/inflorescence, each flower consisting of a single stamen; on the abaxial side of the cyathium nectariferous bracts are often situated

Cyclic – arranged in whorls (usually of foliar structures)

Cyclocytic stomata – encyclocytic stomata; with five or more small subsidiary cells entirely surrounding the guard cells, although not radially elongated

Cylindrical – like a cylinder, i.e. long and narrow with a circular cross-section

Cymbiform – boat-shaped

Cyme – a sympodial partial inflorescence in which the axis terminates in a flower, growth being continued by axillary buds; also used for a compound, more or less flat-topped inflorescence

Cymose inflorescence – adjective of cyme

Cymosely branched – with the branches arranged as in cymes

Cymule – a small cyme

Cypraeiform – (Euphorbiaceae) shaped like a cowrie-shell

Cypsela – (Asteraceae) a type of achene produced by an inferior syncarpous ovary

Cystolith – concretion of calcium carbonate found in cells, often specialized lithocysts, and developing on an intrusion of the cell wall