Plant Terms
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U
V
W
X
Y
Z
A
Abaxial
Dorsal; the side of an organ oriented away from the main axis; underside
of a leaf
Aberrant
Different from the usual
Abrupt
Terminating suddenly
Abscission
Falling off of a leaf or other organ
Acaulescent
Appearing stemless
Accessory fruit
A fleshy fruit developing from a succulent receptacle rather than
from the pistil; for example a strawberry
Accrescent
Increasing in size with age, often referring to the expansion of the
calyx in fruit maturation
Acephalous
Headless
Aceriform
Shaped like a maple leaf
Achene
A small, dry, indehiscent, single-seeded fruit
Achlorophyllous
Without chlorophyll, not green
Acicular
Needle-shaped
Aciculate
Marked as with pin-pricks; needle-shaped
Acidophilous
Acid-loving
Acorn
A hard, dry indehiscent fruit of oaks, with a single, large seed and
cup-like base
Acrid
A sharp, bitter taste
Actinomorphic
Radially symmetrical, so that a line through the middle along any
plane will produce mirror images; regular
Acuminate
Tapering to a slender point
Acute
Forming an angle less than 90°
Adaxial
Ventral; the side of an organ oriented towards the main axis; top
side of a leaf
Adherent
Sticking together of unlike parts
Adnate
Fused to an un-like part, i.e. stamens fused to the petals
Adventitious
Structure or organs developing in an unusual position; for example
roots originating on the stem
Aerial
Occurring above ground or water
Aggregate
Clustered together
Aggregate fruit
A cluster of small fleshy fruits originating from a number of separate
pistils in a single flower
Alkaline
Basic, with a pH greater than 7.0
Alternate
Born singly at each node
Ament
A dense spike or raceme of unisexual flowers; a catkin
Ammophilous
Sand-loving
Anandrous
Without stamens
Androecium
Collective term for all of the stamens in a flower
Androgynophore
Stalk supporting the androecium and gynoecium in some flowers
Androgynous
A condition where the male flowers are above the female flowers in
the same inflorescence
Androphore
Stalk supporting a group of stamens
Anemophilous
Wind pollinated
Angiosperm
A flowering plant
Annual
A plant which grows from seed, flowers, and dies in the same year
Annulus
A row of cells in the walls of a sporangium that shrink or expand
to cause the rupture of the sporangium and release of spores
Antepetalous
Directly opposite the petals
Anterior
In the front; on the side away from the axis
Antesepalous
Directly opposite the sepals
Anther
The pollen bearing portion of the stamen
Antheridium
The male reproductive structure in mosses and ferns, produced at the
gametophytic stage
Anthesis
Time of flowering
Antrorse
Directed upward or forward to the tip
Apetalous
Without petals
Apex
The tip
Aphyllous
Without leaves
Apical
Positioned at the tip of a structure
Apiculate
With a short, abrupt point
Apocarpous
Carpels not fused
Apopetalous
Having separate petals
Appendage
A secondary part attached to a main structure
Appressed
Pressed against or parallel to an organ or surface
Approximate
Borne close together, but not fused
Aquatic
Growing in the water
Archegonium
The female reproductive structure in mosses and ferns, produced at
the gametophytic stage
Arcuate
Moderately arched or curved
Arenicolous
Growing in sandy substrate
Areola
A small, defined area on a surface; for example, the region of a cactus
from which the spines originate
Areolate
With a surface divided into many angular sections; or marked with
areola
Aril
A fleshy outgrowth from the funiculus that partly or wholly encloses
a seed, usually brightly coloured
Aristate
Tapered to an awn or bristle-like tip
Armature
Thorns, spines, or prickles
Articulate
Jointed
Articulation
Point of attachment
Ascending
Growing upwards
Asepalous
Without sepals
Attenuate
Very gradually tapered to a slender apex or base
Auricle
Ear-like lobe
Autogamous
Self-fertilized
Awl-shaped
Short, narrowly triangular and sharply pointed
Awn
A bristle-like projection, often at the tip of a structure
Axil
The angle between the stem and leaf
Axile
A type of placentation; ovules attached where the septae intersect
in the centre of an ovary
Axillary
In the axil of a leaf
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B
Banner
The upper and largest petal of a legume flower
Barbed
With short, rigid, reflexed points
Barbellate
Finely barbed
Barbellulate
With short, stiff hairs or barbs
Bark
The outermost layer of a woody stem
Basal
At the base
Basal placentation
Ovules positioned at the base of a unilocular ovary
Beak
A narrow or prolonged tip
Bearded
Bearing a tuft or tufts of hairs
Berry
A fleshy fruit with many seeds; for example, a tomato
Bicarpellate
With two carpels
Biconcave
Concave on both sides
Biconvex
Convex on both sides
Bidentate
With two teeth
Bidentulate
Slightly two toothed
Biennial
A plant that lives two years
Bifid
Two-branched or lobed
Bifurcate
Two-forked
Bilabiate
Two-lipped
Bilateral
Arranged on two sides
Bipinnate
Twice pinnate; with the divisions divided
Bipinnatifed
Twice pinnately lobed
Biseriate
Arranged in two rows
Bisexual
With both sexes
Bladder
A thin-walled, inflated structure
Blade
The broad part of a leaf
Bloom
A whitish, waxy or powdery covering on the epidermis
Brackish
Somewhat saline
Bract
A reduced or modified leaf that subtends a flower or inflorescence
Bracteate
With bracts
Bracteole
A reduced bract, often with larger main bracts
Bracteose
With many bracts
Bractlet
A small secondary bract borne on a pedicel or hypanthium instead of
below the pedicel
Branch
A division of the main stem
Branchlet
A small secondary branch
Bristle
A short, stiff projection
Bud
An undeveloped shoot or flower
Bulb
A short, underground stem bearing fleshy, scale leaves modified for
food storage, for example, an onion
Bulbil or Bulblet
A small secondary bulb that develops in a leaf axil
Bulbous
Bulb-like
Bundle scar
Scar left by the vascular bundles, seen when leaves fall of stems
Bur
An armed fruit with hooked or barbed spines for seed dispersal
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C
Caducous
Falling off early
Caespitose
Densely tufted
Calcareous
Soil or water with high CaCO3 (lime) content
Callous
Hardened or thickened
Callus
A thickened extension at the base of a grass floret where the lemma
attaches to the rachilla
Calyx
The collective term for sepals
Cambium
Tissue capable of active cell division
Campanulate
Bell-shaped
Canescent
With fine, dense, whitish hairs that give the surface a gray appearance
Capillary
Very slender; hair-like
Capitate
Head-like
Capsule
A dry, dehiscent fruit containing few to many seeds
Carpel
In angiosperms, a modified seed-bearing leaf; a megasporophyll
Carpophore
A slender stalk that supports the two mericarps in fruits of the Apiaceae
(carrot) family
Carinate
Keeled, with one or more longitudinal ridges
Cartilaginous
Firm but flexible
Caryopsis
A dry, one-seeded, indehiscent fruit with the seed coat fused to the
pericarp; a grain
Castaneous
Chestnut coloured
Catkin
A spike-like inflorescence of unisexual flowers, typical of the Salicaceae
(willow) family
Caudal
Tail-like
Caudex
A thickened, often woody, vertical or branched perennial stem; usually
underground
Caulescent
With a definite above ground stem
Cauline
Of the stem
Cernuous
Drooping or nodding
Chaff
Thin, dry scales or bracts; for example on the receptacle in the Asteraceae
(sunflower) family
Chaffy
With chaff
Channelled
With deep longitudinal grooves
Chartaceous
Papery textured and opaque
Chloranthous
With green, leaf-like flowers
Chlorophyll
Green pigment associated with photosynthesis
Chlorotic
Lacking chlorophyll
Cilia
Hairs on a margin
Ciliate
Fringed with cilia
Ciliolate
Minutely ciliate
Cincinnus
A dense, helicoid cyme with flowers only on one side
Cinereous
Ash-coloured due to presence of short, gray hairs
Circinate
Coiled in the bud
Circumsessile
Describing a capsule where the top portion pops off like a lid to
release the seeds
Clasping
Partly or completely surrounding the stem
Clavate
Club-shaped
Clavicle
A tendril
Claw
The lower portion of a petal that is long and narrow
Cleft
Cut into lobes
Cleistogamous
Flowers that are self-pollinated and fertilized because they remain
closed in the bud
Climbing
Growing upward by growing on another structure for support
Coalescent
United together to form one unit
Collar
The region on the outside of a grass leaf where the leaf blade and
the sheath meet
Column
A structure formed by the union of the filaments or the filaments
and the style
Coma
A tuft of hairs on a seed, for wind dispersal
Commisure
A place where two similar parts adjoin
Complanate
Flattened
Compound
With two or more like parts in one organ; for example two carpels
in a single ovary is a compound ovary
Compressed
Flattened
Concave
Curved inward
Confluent
Merging or blending of one part to another
Cone
A dense cluster of sporophylls subtending sporangia on a central axis
Conic
Cone-shaped
Coniferous
Bearing cones or strobili
Connate
The fusion of like parts, for example the fusion of the petals to
each other
Connivent
Converging but not fused
Constricted
Narrowed
Contiguous
Adjoining
Contorted
Twisted or bent
Convergent
Coming together
Convex
Curved outward
Convolute
Rolled up and often twisted in the bud
Copious
In large numbers
Coralloid
Coral-like
Cordate
Heart-shaped, with two rounded lobes
Coriaceous
Thick, tough and leathery
Corm
A short, fleshy underground stem usually covered by papery, modified
leaves; for example, garlic
Cormose
Having a corm
Corniculate
Having small horn-like projections
Corolla
The collective term for the petals
Corrugated
Irregularly folded or wrinkled
Corymb
A flat-topped inflorescence with stalked flowers, the branches are
of different lengths with the lower ones being longer, the terminal
flower matures last
Corymbiform
Corymb-like
Costa
A rib or prominent midvein
Creeping
Growing along the surface of the ground
Crenate
With rounded teeth on the margin
Crenulate
With very small, rounded teeth on the margin
Crest
An elevated ridge
Crosier
The curled top of a young fern frond
Cruciform
Cross-shaped
Cucullate
With a blunt, hood-shaped tip
Culm
The stem of a grass-like plant
Cuneate
Wedge-shaped
Cupulate
Cup-shaped
Cuspidate
With a terminal tooth-like projection
Cuticle
The waxy layer on the epidermis that protects against water loss
Cylindrical
Cylinder-shaped
Cyme
An inflorescence in which the terminal flower matures first
Cypsella
An achene with a pappus (modified calyx) attached, as in some members
of the Asteraceae
Cystolith
An intercellular mineral deposit that accumulated in some of the epidermal
cells of some plants
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D
Deciduous
Falling off
Declined
Curved downwards
Decumbent
The lower part of the stem lying on the ground but with an ascending
tip
Decurrent
Extending below the level of attachment as a wing
Decussate
Opposite leaves that alternate at 90° angles to the pairs above
and below them
Deflexed
Bent abruptly downward
Dehiscent
Splitting open to release contents
Deliquescent
An irregular pattern of branching without a well-defined axis from
bottom to top
Deltate
Triangular
Dendritic
Branching pattern similar to that in a tree; used to describe some
hairs in the Brassicaceae (mustard) family
Dentate
Square-toothed
Denticle
Small tooth-like projection
Denticulate
Finely square-toothed
Depauperate
Stunted or poorly developed
Depressed
Flattened or indented on one end
Descending
Directed downward
Determinate
Described an inflorescence in which the terminal flower blooms first
Diadelphous
A stamen arrangement in which two group of stamens are united by their
filaments; commonly a 9 + 1 arrangement like that found in many legumes
Dichotomous
Branching in pairs
Didynamous
A stamen arrangement in which there are two groups of two stamens
of unequal length
Diffuse
Widely spreading
Digitate
Lobed, veined or divided like fingers of a hand
Dilated
Flattened or expanded
Dimorphic
Having two different forms
Dioecious
Male and female flowers on separate plants
Discoid
Resembling a disc
Disjunct
Occurring in widely separated geographic areas
Dissected
Deeply divided
Distal
Towards the tip
Distichous
2-ranked; in two opposite rows
Distinct
Separate
Divaricate
Widely spreading
Divergent
Spreading away from the main axis
Divided
Cut or lobed to the base or midrib
Dolabriform
Ax-shaped; attached at some other point than the base, usually near
the middle
Dorsal
The side of an organ oriented away from the main axis
Dorsifixed
Borne on the back
Downy
Covered in soft, fine hairs
Drooping
Hanging down
Drupe
A fleshy, one-seeded fruit, seed with a stony endocarp
Drupelet
A small drupe; for example, the individual segments of a raspberry
Dyad
A group of two
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E
Ebracteate
Without bracts
Echinate
With prickles or spines
Edaphic
Pertaining to the soil
Eglandular
Without glands
Elaminate
Without a blade
Ellipsoid
Elliptic in outline
Elliptic
In the shape of a flattened circle, more than twice as long as wide
Elongate
Drawn out
Emarginate
Shallowly notched at the apex
Emergent
Growing above the surface of the water
Emersed
Growing with at least some parts in the water
Enation
A small, modified leaf; a projection or outgrowth of an organ or structure
Endemic
Unique to a particular region
Ensiform
Sword-shaped
Entire
With a smooth margin
Entomophilous
Insect pollinated
Epappose
Without a pappus
Ephemeral
Lasting a short time
Epicalyx
Bracts that resemble the calyx
Epidermis
The outermost cellular layer of a no-woody plant organ
Epigynous
Inferior ovary
Epipetalous
Attached to the corolla
Episepalous
Attached to the sepals
Equilateral
With sides of equal shape and length
Equitant
2-ranked leaves that overlap at the base, with the blades sharply
folded lengthwise; leaf blades oriented edge-wise to the stem
Erect
Vertical
Erose
With a jagged margin
Evergreen
Having green leaves throughout the winter
Excurrent
Extending beyond the tip or margin as a mucro or awn
Exotic
Non-native
Exserted
Extending beyond another structure; for example, when the stamens
are longer than the perianth, the stamens are exserted
Exstipulate
Without stipules
Extrastaminal
Outside of the stamens
Extrorse
Turned outwards
Exude
To secrete
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F
Faceted
With many plane surfaces
Falcate
Sickle-shaped
Farinose
Mealy-textured, often whitish or greyish
Fascicle
A bundle arising from a common base
Fastigiate
Broom-like appearance
Fertile
Capable of bearing seeds or pollen
Fetid
An offensive odour
Fibrillose
Having small fibres
Fibrous
Having fibres
Fibrous roots
A branched root system, with all of the branches of about equal thickness
Filamentous
Like a filament; thread-like
Filiform
Thread-like
Fimbriate
Fringed, usually with hairs
Flabellate
Fan-shaped
Flaccid
Limp
Flagellate
With long, slender runners
Flavescent
Yellowish
Fleshy
Thick and pulpy
Flexuous
Curved or bent
Floccose
Bearing tufts of long and tangled hairs
Floret
A reduced flower; for example flowers in the Asteraceae (sunflower)
or Poaceae (grass) families
Flower
The reproductive structure of a plant; usually with sepals, petals,
stamens and a pistil
Fluted
Furrowed or grooved
Foliaceous
Leaf-like in appearance
Foliage
Leaves
Follicle
A fruit with one carpel containing few to several seeds, splits along
one line of dehiscence at maturity
Forb
A non-grasslike herb
Forked
Divided into two more or less equal branches
Fovea
A small pit or depression
Free
Not attached to other organs
Fringed
With hairs or bristles on the margin
Frond
The leaf of a fern
Fruit
A ripened ovary and associated structures
Funnelform
Funnel-shaped
Furcate
Forked
Fusiform
Spindle-shaped
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G
Galea
Helmut-shaped upper lip of some two-lipped petals
Gall
An abnormal growth caused by insects
Gametophyte
Haploid, the generation of a fern or moss life cycle
Geitonogamy
Pollination between flowers of the same plant
Gelatinous
Jelly-like in texture
Gibbous
Enlarged towards one side
Glabrate
Glabrous with age
Glabrous
Smooth, hairless
Gland
A structure that secretes sticky or oily substances
Glandular
Having glands
Glaucous
Whitish or bluish in colour, often due to a waxy coating
Globose
Spherical in shape
Glochid
A barbed hair or bristle found in the Cactaceae (cactus) family
Glomerulate
With distinct, dense clusters
Glomerules
Small, dense clusters
Glumes
Two bracts at the base of a grass spikelet, empty
Glutinous
Gluey or sticky
Grain
A dry, one-seeded, indehiscent fruit with the seed coat fused to the
pericarp; fruit type of almost all of the grasses
Gymnosperm
Plants producing seeds in cones; for example, spruce (Picea)
Gynaecandrous
An inflorescence where the female flowers are borne above the male
flowers
Gynandrous
With the stamens fused to the pistil
Gynobasic
A style that is attached at the base of the ovary rather that at the
tip
Gynoecium
The female portion of a flower
Gynophore
An elongated stalk bearing the pistil in some species
Gynostegium
A central column formed by the fusion of the stamens and pistil; found
in the Asclepiadaceae (milkweed) and Orchidaceae (orchid) families
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H
Haploid
Containing only one set of chromosomes
Haplopetalous
With a single series of petals
Hastate
Leaf bases with divergent lobes
Head
A dense cluster of sessile or subsessile flowers; for example, the
inflorescence of an aster
Helicoid
Coiled like a spiral or helix
Herb
A plant without a persistent above ground woody stem
Herbage
The non-reproductive parts of a plant
Hesperidium
A fleshy berry-like fruit with a tough rind and several sections (carpel);
for example, an orange
Heterandrous
With stamens or anthers of different forms or sizes
Heteromorphic
Of more than one kind
Heterosporous
Having two kinds of spores, megaspores (larger) and microspores (smaller)
Hip
A berry-like fruit composed of an enlarged hypanthium surrounding
numerous achenes
Hispid
With long, stiff, straight hairs
Hispidulous
Minutely hispid
Hirsute
With stiff, spreading hairs
Hoary
With short fine, white or gray hairs
Homoeandrus
With one kind of stamens or anthers
Homomorphic
All of the same kind
Homosporous
Having one kind of spores
Hood
A hollow, arched covering
Horn
A tapering projection
Husk
A tough outer covering on some seeds or fruits
Hyaline
Thin and transparent
Hybrid
The offspring of a cross between two parents of different varieties,
species or genera
Hydathode
An opening which exudes water
Hydrophyte
A plant growing in water
Hypanthium
Cup-shaped or tubular structure formed by the fusion of the sepals,
petals, and filaments that surrounds the pistil
Hypogynous
A superior ovary without a hypanthium
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I
Imbricate
Overlapping in rows
Immersed
Growing under water
Imperfect
Referring to flowers with either male or female parts only
Implicate
Twisted together
Impressed
Situated below the surface
Incarnate
Flesh coloured
Incised
Deeply lobed or divided
Inclined
Rising upward at a moderate angle
Incurved
Curved inwards
Indehiscent
Not splitting open at maturity
Indeterminate
An inflorescence where the lower flowers mature before the terminal
flower
Indurate
Hardened
Indusium
The membranous outgrowth of a fern that covers the sorus wholly or
in part
Inferior
Attached beneath, as an ovary where the sepals, petals and stamens
are attached above the base of the ovary
Infertile
Sterile or inviable
Inflated
Swollen or expanded
Inflexed
Curved inwards
Inflorescence
The arrangement of flowers on a plant
Infrastipular
Below the stipules
Innate
Borne at the apex
Insectivorous
Capturing and digesting insects
Inserted
Attached or growing out of
Internode
The portion of the stem between two nodes
Interrupted
Not continuous
Introrse
Turned inward
Inverted
Reversed
Involucel
Bracts on the secondary branches of a compound inflorescence
Involucre
Bracts that subtend the main inflorescence or solitary flowers
Involute
Inrolled or curled under margins
Iridescent
Displaying many colours
Irregular
Bilaterally symmetrical so the flower can be divided in half in only
one plane to give a mirror image
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J
Joint
The section of the stem from which a leaf or branch arises; a node;
a point of articulation
Jointed
Having nodes
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K
Keel a prominent longitudinal ridge; boat-shaped
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L
Labellum
Lip; modified petal of an orchid
Labiate
Lipped
Labium
The lower lip of a bilabiate corolla
Lacerate
Margin irregular and jagged, appearing torn
Laciniate
Deeply dissected into parallel, narrow segments
Lacuna
An empty air space
Lamella
An erect scale on the petal that forms part of the corona in some
flowers
Laminate
With a flat blade; with plates or layers
Lanate
Woolly; covered in long, tangled hairs
Lanceolate
Lance-shaped, broadest near the base and tapering to the tip
Lateral
Borne on the side
Latex
A milky sap
Laticifer
A latex bearing channel
Lax
Loose
Leaf
The photosynthetic organ of a plant
Leaflet
A leaf-like segment of a compound leaf
Leaf scar
The scar remaining after a leaf falls
Leaf sheath
The stipules of the leaves surrounding the stem to form a sheath
Legume
The pod-like fruit of members of the Fabaceae (legume) family that
opens along two lines to release the seeds, not constricted between
the seeds
Lemma
The lower bract of the grass floret, often awned from the back or
tip
Lenticels
A slightly raised, often lens-shaped area on the surface of a young,
woody stem
Lenticular
Lens-shaped
Ligule
A membranous or hairy extension on the inside of the leaf sheath in
grasses and grass-like plants; or the strap-like corolla of a ray
flower in the Asteraceae (sunflower) family
Limb
A tree branch or the broadened part of a petal or leaf
Linear
Long, flat and narrow with parallel sides
Lobate
In the form of a lobe
Lobe
A division or segment of an organ, may be rounded
Locule
A chamber inside the ovary
Loculicidal
Describing a capsule that opens longitudinally to expose the locule,
the line of dehiscence is along a midrib of the carpel
Loment
A pod-like fruit found in the Fabaceae (legume) family that opens
along two lines of dehiscence, constricted between the seeds
Lunate
Crescent shaped
Lyrate
With a large, rounded terminal lobe and smaller lateral lobes
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M
Macro-
Prefix meaning large
Malodorous
Having a bad odour
Malphigian hair
A straight hair tapering to both free ends, attached in the middle
Mammillate
With one or more nipple-like projections
Many
More than 10
Margin
The edge
Marginate
With a distinct margin
Mealy
Powdery, dry and crumbly
Median
Of the middle
Megasporangium
A spore sac containing megaspores
Megaspore
A female spore which will give rise to the female gametophyte
Megasporophyll
A modified leaf which bears the megasporangia
Membranous
Thin and flexible, usually translucent
Micro-
Prefix meaning small
Microsporangium
A spore sac containing microspores
Microspore
A male spore which will give rise to the male gametophyte
Microsporophyll
A modified leaf which bears the microsporangia
Midrib or Midvein
The central rib or vein of a leaf or other organ
Monad
A single individual that is few from other such individuals
Monadelphous
A stamen arrangement in which all of the stamens are united by their
filaments to form a tube around the pistil
Moniliform
Like a string of loosely spaced beads
Monochasium
A type of inflorescence with only one main axis
Monoecious
Both male and female flowers on the same plant
Monomorphic
With a single form
Mottled
With coloured spots or blotches
Mucilaginous
Slimy and moist
Mucro
A short, sharp, abrupt terminal point
Mucronate
Having a mucro
Multiple fruit
A fruit formed from several individual flowers on a single axis; for
example, the pineapple or fig
Muricate
With small, sharp projections or points
Mycorrhiza
A mutually beneficial relationship between a fungus and the root of
the plant
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N
Natant
Floating in the water; immersed
Neck
Any constricted part of a plant
Nectar
A sugary, sticky fluid secreted by many plants, usually to attract
pollinators
Nectar guides
Lines or spots which may be invisible to the human eye except under
UV light, used to direct pollinators to nectar
Nectary
An organ which produces nectar
Nerve
A vein or rib of a leaf or other organ, usually referring to the lateral
veins
Net-veined
Veins in the form of a network
Nodding
Bent to one side and downward
Node
The point of attachment of a leaf to the stem
Nodulose
With small swollen joints
Numerous
More than 10
Nut
A hard, dry, indehiscent fruit, usually with a single seed
Nutlet
A small nut, similar to an achene; one of the lobes or sections of
the mature ovary of some members of the mint or borage families
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O
Obclavate
Club-shaped, with the attachment at the broad end
Obcompressed
Compressed opposite the usual way
Obcordate
Inversely heart-shaped, with the attachment at the narrow end
Obdeltoid
Inversely triangular, with the attachment at the narrow end
Oblanceolate
Inversely lance-shaped, with the attachment at the narrow end
Oblique
Slanted; having unequal sides or an asymmetrical base
Oblong
Much longer than wide with nearly parallel sides
Obovate
Inversely ovate, with the attachment at the narrow end
Obtuse
Forming an angle greater than 90°
Ocrea
A membranous sheath at nodes of the stem in the Polygonaceae (buckwheat)
family, formed by the fusion of stipules
Odd-pinnate
Pinnately compound with a terminal leaflet, so that there is an odd
number of leaflets
Oil tube
Narrow ducts in the walls of the fruits in some of the Apiaceae (carrot)
family, contain volatile oils
Olivaceous
Olive-green
Operculate
With an operculum
Operculum
A small lid; for example, the cap of a circumsessile capsule
Opposite
Borne across from one another at the same node
Orbicular
Round and flattened
Organ
A plant part with a specific function
Orfice
An opening or mouth
Oval
Broadly elliptic, the width over one half the length
Ovate
Flat and egg shaped; rounded at the base and tapered to the tip
Ovoid
Egg-shaped
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P
Palea
The uppermost or innermost of the two bracts that subtend the grass
floret
Pallid
Pale
Palmate
Divergent from a common point of attachment, like fingers on a hand
Palmate-pinnate
With the primary leaflets palmately arranged and the secondary leaflets
pinnately arranged
Palmatifed
Palmately cleft or lobed
Panicle
A compound inflorescence in which flowers are borne on branched branches
Paniculate
Having flowers in pancicles
Paniculiform
Referring to an inflorescence that resembles a panicle
Papilla a small blunt projection arising from a flat surface
Papillate
Covered in small blunt projections
Pappose
Bearing a pappus
Pappus
The modified calyx of the flower of members of the Asteraceae (sunflower)
family, attached on the top of the inferior ovary, may be scale-like
or a series of bristles or awns
Parietal
Attached to the inner surface or wall of an enclosed structure
Patent
Spreading or expanding
Pectinate
Having closely parallel, slender, toothlike projections like a comb
Pedate
Palmately divided
Pedicel
The stalk bearing of a flower in an inflorescence
Pedicellate
Borne on a pedicel
Peduncle
The stalk of an inflorescence or a solitary flower
Pedunculate
Having a peduncle
Peltate
Having the stalk attached at the center of the back or underside
Pendulous
Hanging downward
Perennial
A plant that lives three or more years
Perfect
Describing flowers that have both male and female parts
Perfoliate
With the leaf base completely encircling the stem
Perforate
With holes or perforation
Perianth
The collective term for the sepals and petals, or either of them if
one is absent
Perigynium
The sac-like or scale-like structure that encloses the ovary in Carex
Perigynous
A hypanthium surrounds but is not fused to or completely enclosing
the ovary
Peripheral
Outside of or external to
Persistent
Remaining attached after similar parts are normally dropped and their
function has been completed
Petal
The second outermost sterile appendage of a flower, usually soft-textured
and coloured
Petalode
A structure, usually a stamen, which resembles a petal
Petaloid
Petal-like
Petiolate
With a petal
Petiole
The stalk of a leaf
Petiolule
The stalk of a leaflet in a compound leaf
Phalange
Two or more stamens joined by their filaments
Phyllary
An involucral bract of the Asteraceae (sunflower) family
Phyllode
An expanded, bladeless leaf which is derived from a flattened petiole
Piliferous
Tipped with a fine, hair-like structure
Pilose
With straight, spreading hairs
Pin
A flower with a long style and short stamens
Pinna
A primary segment of a pinnately compound leaf
Pinnate
Divided or branched with the parts attached in two opposite rows along
a main axis
Pinnatifed
Pinnately lobed, but not divided all the way to the central axis
Pinnatisect
Pinnately divided into narrow segments
Pinnule
A secondary or ultimate segment of a leaf that is pinnately divided
two or three times
Pip
The small seed of a fleshy fruit
Pistil
The female unit of a flower, made of the ovary, style and stigma
Pistillate
Female; with functional female parts only
Pit
A small depression
Plait
A fold or pleat
Planoconvex
With one face flat and the other low-rounded
Plicate
With a series of longitudinal folds, like a fan
Plumose
Like a feather, due to soft spreading hairs
Pod
A dry, dehiscent fruit; a general term for a legume or follicle
Pollen
The mature microspores, released by the male organ (stamens or microsporangia)
Pollinium
A waxy mass of pollen
Pome
A fleshy, indehiscent fruit derived from an inferior ovary, the fleshy
part is the hypanthium; for example, an apple
Pore
A small opening
Prickle
A small, sharp outgrowth of the epidermis
Procumbent
Prostrate and lying flat on the ground
Prophyll
One of the paired bracteoles subtending flowers in some rushes (Juncaceae)
Prostrate
Lying flat on the ground
Psammophyte
Sand-loving plant
Pseudobulb
A bulbous thickening of the stem found in many orchids
Puberulent
Minutely pubescent
Pubescence
A covering of hairs
Pubescent
Hairy
Pulvinus
A swelling or enlargement at the base of a petiole or petiolule
Punctate
Dotted with glands or pitted
Puncticulate
With tiny dots on the surface
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Q
Quadrangular
Four angled
Quadrate
Square or rectangular
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R
Raceme
An inflorescence in which all of the flowers are individually stalked
along a main axis
Racemose
Having flowers in racemes
Rachilla
The secondary axis of a branched inflorescence
Rachis
The main or primary axis of an inflorescence or pinnately compound
leaf
Radiate
With structures radiating from a central point
Rank
A vertical row
Ranked
Arranged in vertical rows
Ray
The primary branches of an umbel; the strap-like corolla of the ray
flowers in the Asteraceae (sunflower) family
Receptacle
The structure to which the flowers are attached at the terminal portion
of the pedicel
Reclining
Bending or curving downward
Recumbent
Leaning or resting on the ground
Recurved
Curved downward or backward
Reflexed
Projecting downward
Regular
Radially symmetrical
Remote
Widely separated
Reniform
Kidney-shaped
Replum
A persistent, membranous partition that bears ovules on its margins
and separates the two valves of pods in the Brassicaceae (mustard)
family; a false septum
Resinous
Bearing resin, often sticky
Reticulate
With a net-like pattern
Retrorse
Projecting backward or downward
Retuse
Having a notch in a rounded or obtuse apex
Revolute
Curled or rolled backward along the edges
Rhizoid
A root-like structure without vascular tissue
Rhizomatous
Having rhizomes
Rhizome
A creeping underground stem often bearing scales
Rib
A main longitudinal vein in a structure, particularly if raised above
the surrounding surface
Rigid
Stiff and flexible
Rind
A thick outer covering
Riparian
Growing along the banks of streams, springs, or seeps
Root
The portion of the plant axis lacking nodes and leaves and usually
found below ground
Rootlet
A small root
Rosette
A cluster of leaves arising from a common point
Rostellum
A small beak
Rostrate
With short, stout, terminal beak
Rostrum
A beak-like structure
Rotate
Describing a corolla that has a short tubular portion and widely spreading,
flattened lobes
Rotund
Round
Rudimentary
Imperfectly developed
Ruminate
Roughly wrinkled, as if chewed
Runcinate
Sharply pinnatifed, with the segments directed downwards
Runner
A slender prostrate stem rooting at the nodes or at the tip
Rugose
With cross-ridges or wrinkles
Rugulose
With a finely wrinkled surface
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S
Sac
A bag-shaped compartment
Saccate
Sac-shaped
Sagittate
Arrowhead-shaped
Salverform
Trumpet-shaped, usually describing the shape of a sympetalous corolla
Samara
A dry indehiscent, winged fruit
Sap
The juice of a plant
Scabrous
Roughened with stiff hairs or tooth-like projections
Scale
A small, dry bract that subtends and often encloses a flower
Scape
A leafless stem that bears an inflorescence
Scapose
Having a stem that resembles a scape
Scarious
Thin, dry, non-green and membranous in texture
Schizocarp
A dry fruit that breaks into two separate segments at maturity
Scorpioid
Coiled like a scorpion’s tail
Scutellum
A small plate-like structure
Secund
Having parts that appear to arise only from one side of an axis
Sepal
The outermost sterile appendage of the flower (excluding the bracts),
usually green
Sepaloid
Sepal-like
Septate
Divided or partitioned into sections by cross-walls
Septicidal
Describing a capsule that splits open along the septae
Septum
An internal partition
Sericeous
With long silky hairs
Serrate
Saw-toothed
Serrulate
With finely saw-toothed edges
Sessile
Without a stalk, attached directly
Setaceous
Bristle-like
Setose
Covered with bristles
Sheath
The portion of an organ which at least partially surrounds another
organ
Shoot
A young stem or branch
Shrub
A woody plant, with several stems
Silicle
A fruit in the Brassicaceae (mustard) family which is divided into
two segments by a replum, less than 2 x as long as wide
Silique
A fruit in the Brassicaceae (mustard) family which is divided into
two segments by a replum, greater than 2 x as long as wide
Simple
Unbranched or undivided
Sinuate
Wavy-margined
Sinus
The indentation or space between adjacent lobes or divisions of a
structure such as a leaf or corolla
Solitary
Occurring singly and not borne in a cluster or group
Sorus
A cluster of sporangia borne on a fern frond
Spadix
A thick, dense, fleshy spike
Spathe
One or two closely associated bracts that subtend a flower or inflorescence
Spatulate
Spatula-shaped
Spiciform
An inflorescence with the general appearance of a spike
Spike
An unbranched inflorescence in which the flowers are all sessile on
a main axis
Spikelet
A small spike or secondary spike
Spine
A stiff, slender, sharp-pointed structure arising from below the epidermis;
modified leaf or stipule
Spinulose
With weakly spine-tipped projections
Sporangium the spore sac or spore producing structure of a plant
Spore
A reproductive cell resulting from meiotic cell division in a sporangium
Sporophyll
A sporangium-bearing leaf, often modified in structure
Spur
A slender, tubular appendage extending backward from the base of a
sepal or petal
Stamen
The male, pollen-producing organ of a plant, comprised of the anther
and filament
Staminate
Male, with functional male parts only
Staminode
A reduced or modified stamen
Stem
The portion of a plant axis bearing nodes, leaves, usually found above
ground
Sterile
Infertile
Stigma
The pollen-receptive portion of the pistil, either borne on the terminal
portion of the style or sessile on the ovary
Stipe
A supporting stalk, commonly describing the stalk of an ovary or of
a fern frond
Stipitate
Born on a stalk
Stipules
Paired, modified leaves at the base of the petiole, may be membranous
or leaf-like
Stolon
An elongate, horizontal stem creeping along the ground and rooting
at the nodes or the tip
Stramineus
Straw-coloured
Striate
With fine, parallel longitudinal lines or nerves
Strigose
With stiff, appressed hairs
Strigulose
Minutely strigose
Strobilus
A cone-like cluster of sporophylls on an axis
Stylopodium
A swollen, disk-like base of a style; for example, in the flowers
of the Apiaceae (carrot) family
Submersed
Growing under water
Subtend
Attached below and extending upward
Subterranean
Below the surface of the ground
Subulate
Awl-shaped
Succulent
Thick, fleshy and watery
Suffrutescent
Somewhat shrubby
Superior
Attached above, as an ovary where the sepals, petals and stamens are
attached below the base of the ovary
Suture
A line of fusion or dehiscence
Syconium
A hollow inverted receptacle with the flowers on the inside; for example,
the fig
Sympetalous
Fused petals
Syncarpous
With united carpels
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T
Taproot
A root system with one dominant vertical root and usually with secondary
roots or root hairs
Tassel
The staminate inflorescence in corn
Taxon
A taxonomic entity of any rank (family, genus, species)
Temperate
Region of the world between 23.5° N and 66.67° N latitude
and between 23.5°S and 66.67°S
Tendril
A thread-like, often branched appendage that coils around other objects
to provide support for a climbing plant; a modified leaf, leaflet
or branch
Tepal
A term for a part of the perianth used when the sepals and petals
cannot be distinguished because of similarity in size and shape
Terete
Round in cross section
Terminal
At the tip or apex
Ternate
Divided into three’s
Tetradynamous
Having four long and two short stamens, typical of the Brassicaceae
(mustard) family
Thorn
A stiff, woody, modified stem with a sharp point
Thrum
A flower with a short style and long stamens
Tomentose
With a covering of dense, woolly hairs
Tomentulose
Slightly tomentose
Trailing
Prostrate and creeping but not rooting
Trifid
Branched into three branches or lobes
Trigonous
Three sided and triangular in cross-section
Tripinnate
Pinnately divided three times
Truncate
Squared at the tip
Tuber
A fleshy rhizome that functions as a food storage organ; for example,
the potato
Tubercle
A small swelling
Tuberculate
Having tubercles
Tuberous
Tuber-like
Tufted
Clumped; with stems clustered together at the base
Turgid
Swollen, expanded or inflated
Tussock
A tuft or clump of small grasses or sedges
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U
Ubiquitous
Widespread
Ultimate
The final section or division
Umbel
An inflorescence with several to many stalked flowers arising from
a common point
Umbellet
A small, secondary umbel of a compound umbel
Umbelliform
Like an umbel
Undulate
Wavy
Urceolate
Urn-shaped or pitcher-shaped
Utricle
A small, one-seeded fruit in which the pericarp is thin, dry, and
easily removed from the seed
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V
Variegated
Marked with patches or spots of different colours
Variety
A taxonomic category below the species and subspecies level
Vascular
Referring to tissue that conducts water or nutrients
Vein
A vascular bundle
Velamen
The thick spongy layer on the roots of some epiphytic orchids
Velutinous
Velvety
Venation
The pattern of veins
Ventral
Adaxial; referring to the side of a structure oriented towards the
main axis
Verrucose
Warty
Verticel
A whorl
Verticillate
Whorled
Villous
Covered with long, soft hairs
Vine
A plant with a stem supported by climbing on other species
Virescent
Becoming green
Viscid
Sticky or gummy
Viviparous
Sprouting on the parent plant
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W
Wart
A small, firm protuberance
Weed
An aggressive plant which colonizes areas it is not native to
Whorled
With three or more attached at the same level
Wing
A thin, flat margin bordering or extending from a structure
Woolly
With long, soft, entangled hairs
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X
--
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Y
--
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Z
Zygomorphic
Bilaterally symmetrical, so that a line drawn through the middle of
the structure will only produce a mirror image along one plant; irregular
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