Achene: a
small, dry, indehiscent fruit with a thin fruit wall surrounding a single seed
Acuminate:
having an apex with concave sides that gradually tapers into a sharp point
Acute:
having an apex with straight sides tapering into a point with an angle of less
than 90°
Agamospecies: in
plants that usually reproduce asexually, a distinct form that reproduces itself
faithfully, and that may have been treated as a species by some taxonomists
Alternate: of
leaves, having only one leaf arise at each node
Anastomosing:
fusing, e.g. of leaf veins that branch then meet and reconnect
Androecium:
collectively, all of the stamens of a flower
Androgynophore: a
stalk that elevates the sexual parts of a flower above the receptacle and
perianth, especially in passionflowers
Annual: a
plant that lives for only one year
Annular:
ring-shaped
Anther:
the upper portion of a stamen, which produces and releases pollen
Apex:
tip or uppermost portion of a plant organ
Apiculate:
having an apex that ends abruptly in a short, narrow point
Appressed:
lying flat against another part, especially of hairs
Arcuate:
curved like a bow; of leaf venation, having several veins that originate at the
base and curve towards the apex
Aril: a
fleshy structure produced at the hilum of a seed, or a fleshy coating over the
whole seed
Ascending: of
a stem, not erect but rising upward at an angle
Attenuate:
gradually tapering to a long, thin point
Auricle: an
appendage or lobe, usually paired at the base of a leaf, that is fancied to be
ear-shaped
Auriculate:
having auricles
Awn: a
narrow extension or bristle at the apex of a leaf, sepal or bract
Axil:
the angle formed by the juncture between a stem and a petiole or lateral branch
Axillary:
arising from a leaf axil; lateral
Basal: of
the base or arising from the base; of leaves, those that are produced at ground
level rather than on the stem
Base:
the lower part of an organ, nearest the ground or the point of attachment to
other structures
Basionym:
the first published name from which a plant’s specific epithet is derived
Berry: a
fleshy fruit, derived from a compound ovary or a solitary carpel, with more
than one seed and without a pit
Biennial: a
plant that grows vegetatively for one year, then flowers and dies in its second
year
Bifid:
split into two parts or lobes, especially at the apex of an organ
Bilabiate: of
a calyx or corolla, bilaterally symmetrical with a two-lipped appearance (e.g.,
many mint flowers)
Bilaterally
symmetrical: divisible into equal, mirror-image halves
only along one plane; also called “irregular” or “zygomorphic”
Biotype: a
population or group of populations sharing genetic or morphological features
that distinguish them from other members of their species
Bipinnately
compound: of leaves, pinnately compound with the main divisions
of the leaf themselves pinnately divided into leaflets (often written as
“2-pinnate”; tripinnately compound leaves have three orders of division)
Biserrate: of
leaf margins, having two sizes or grades of serrate teeth, with large teeth
that themselves have toothed margins
Blade:
the main portion of a leaf or leaflet, usually broadened and flattened
Bract: a
leaflike or scalelike structure that subtends a flower or an inflorescence or a
branch thereof
Bracteole: a
small bract subtending an individual flower; term usually used only when larger
bracts are found elsewhere in the inflorescence
Bulb: a
short, compact underground stem with thick, fleshy scales or leaves developed
as storage organs (e.g., an onion)
Calyx:
the sepals collectively, especially when fused
Cambium: in
a stem or root, a ring of cells one layer thick that divides repeatedly to
produce tissues; a vascular cambium separates secondary xylem from secondary
phloem
Campanulate: of
a fused calyx or corolla, bell-shaped
Capitate:
head-like; of an inflorescence, with flowers tightly clustered and arising near
the same point
Capitulum: a
head; the characteristic inflorescence of the composite family, consisting of
disk and/or ray florets clustered on a receptacle, subtended by a calyx-like involucre
of bracts (phyllaries), the whole resembling a single flower
Capsule: a
dry fruit, derived from a compound ovary, with a thin wall that splits at
maturity to release the seeds
Carpel: a
simple pistil, or a unit of a compound gynoecium, formed of one modified leaf,
with a unilocular ovary, style (usually) and stigma; multiple carpels may fuse
to create a compound pistil
Carpophore: in
the carrot family, a stalk extended from the receptacle to which the two
carpels (developing into mericarps) are attached at the bifid apex
Cartilaginous:
with a firm but pliable texture, like cartilage
Catkin: a
small, dense spikelike inflorescence consisting of reduced unisexual
wind-pollinated flowers, without perianth and subtended by bracts
Cauline:
referring to the stem; of leaves, borne on the stem (in contrast to basal
leaves)
Ciliate: of
leaves, sepals etc., having hairs along the margin
Clasping: of
a leaf base, with projections that wrap around the stem
Claw:
especially of petals, a sharply narrowed, stalk-like base
Commissure: in
fruits of the carrot family, the attachment of the two mericarps to one another
by the sides facing the carpophore; the plane along which the mericarps
separate in most species
Compound:
made up of more than one part
Compound
leaves: leaves divided into multiple leaves rather than a
single simple blade
Compound
ovary: the lower portion of a pistil deriving from the fusion
of several carpels; may have one large round locule, or as many locules as
carpels
Compound
umbel: the typical inflorescence of the carrot family, an
umbel of rays each bearing a terminal umbellet of flowers
Cone: a
reproductive structure in gymnosperms, in which ovules are borne naked on
protective bracts, rather than enclosed in an ovary as in all flowering plants
Cordate:
heart-shaped, with the broad notched end basal
Coriaceous:
leathery
Corolla:
the petals collectively, especially when fused
Corona:
used to refer to a variety of “crown-shaped” structures, such as an extra whorl
of colorful filaments between the petals and the stamens (in passionflowers),
an ornate reproductive structure (in milkweed relatives), or a pappus
consisting of a ring-shaped ridge or scale atop the fruit (in the composite
family)
Cortex: a
ring of parenchymatous tissue inside the epidermis or bark, and outside the
vascular tissue, of a stem or root
Corymb: a
branching inflorescence with a flat top, with the outermost flowers maturing
first
Cosmopolitan:
occurring nearly worldwide (within habitat restrictions); refers to a plant
that is widely distributed on several continents
Crenate: of
leaf margins, having rounded teeth
Crenulate:
crenate, with the teeth small
Crisped: of
leaf margins, wavy in a plane perpendicular to the surface of the leaf
Cuneate:
wedge-shaped; tapering with straight sides
Cuspidate:
terminating abruptly with a short sharp point; similar to apiculate
Cyme: a
branching inflorescence with the terminal flower maturing first, sometimes
complex in shape
Cymule: a
small cyme, often a segment of a larger inflorescence
Cypsela: a dry,
single-seeded fruit resembling an achene, but derived from an inferior ovary
thus having an extra layer of tissue as part of the fruit wall; characteristic
of the composite family
Dehiscent: of
a fruit, remaining intact rather than splitting open to release seeds
Deltoid:
broadly triangular, with the base being one of the flat sides
Dentate:
having outward-pointing teeth on the margins
Denticulate:
dentate, with the teeth small
Dioecious:
having unisexual flowers, with the sexes borne on different plants (as
contrasted with monoecious)
Disk
floret: in Asteraceae, a radially symmetrical flower, often
borne on the central portion of the receptacle of a capitulum (as contrasted
with ray florets)
Distal: of
the end of a part or organ that is farthest from its attachment to the rest of
the plant (contrasted with proximal)
Drupe: a
fleshy fruit, with each seed surrounded by a hard endocarp (pyrene), often
one-seeded with a large pith (e.g., an olive)
Elliptical:
oval, broadest in the middle, narrower above and below the middle
Endemic:
native only to a specified area, not found in the wild elsewhere
Endocarp:
the innermost layer of a fruit wall (pericarp), sometimes differentiated, e.g.
into a hard protected layer
Endosperm:
nutritive tissue contained inside a seed
Entire: of
leaf margins, continuous and straight, without teeth or lobes
Epicalyx: a
whorl of bracts beneath a flower that resemble a calyx, especially in the
cotton family
Epidermis:
the outermost layer of cells of young or non-woody plant organs
Erect:
standing upright
Exocarp:
the outermost layer of a fruit wall (pericarp)
Follicle: a
dry fruit, derived from a single carpel, that splits along one side to release
seeds
Filament:
usually, the sterile stalk of a stamen, which bears the anther
Funiculus:
the stalk by which a developing seed is attached to the placenta in the ovary
Funnelform:
especially of fused corollas, funnel-shaped, gradually tapering toward the base
Fusiform: of
three-dimensional structures; spindle-shaped, widened in the middle
Glabrate:
almost glabrous, very sparsely hairy
Glabrous:
hairless, not pubescent
Glaucous:
glabrous and with a waxy coating
Globose:
roughly spherical
Gynobasic: of
a style, arising at the center and from the base of a deeply lobed compound
ovary (e.g. in many mints)
Gynoecium:
collectively, all of the carpels of a flower, whether separate or fused into a
compound pistil
Half-inferior: of
an ovary, often used to refer to the ovary of a flower that has a hypanthium
but in which the hypanthium is not fused to the ovary (hence, the ovary is
visible and not truly inferior)
Hastate: of
leaf bases, shaped like an arrowhead with outward-pointing basal lobes
Head: a
capitulum, an inflorescence in which many flowers are borne in a tight cluster
at the end of the peduncle; in the composite family, often having both ray and
disk florets and resembling a single flower
Hermaphroditic: of
flowers, possessing both male and female sexual organs; also called perfect or
bisexual
Hilum:
the scar that is left on a seed when it separates from the funiculus
Hypanthium: a
tube formed by complete fusion of the basal parts of the calyx, corolla and
filaments, ranging from very short to cup-shaped to elongated and tubular,
often fused also to the sides of the ovary (which is then inferior)
Indehiscent: of
a fruit, not splitting open to release seeds
Inferior: of
an ovary, having the lowermost portions of the other floral whorls fused to the
sides of the ovary so that only the top of the ovary is visible inside the
flower and the ovary appears to be embedded in the receptacle, with the free
portions of the other whorls apparently borne above it
Inflorescence:
all of the flowers borne on a single flowering axis
Intercalary: of
an inflorescence, produced on the stem below the apex, with more vegetative
growth above
Internode: a
segment of a stem between branches or leaves
Involucre: a
whorl of bracts subtending or surrounding a flower or group of flowers
Keel: a
longitudinal ridge down the center of a bract or sepal; in many legumes, two
petals that form a shape fancied to resemble the keel of a boat
Lanceolate:
shaped like the head of a lance, broader below the middle; narrower than ovate
Lateral: at
or of the side; of a flower or inflorescence, borne along the stem, usually
arising from leaf axils, rather than at the tip of the stem
Lax: of
a branching inflorescence such as a panicle, open and flexible with space
between flowers rather than crowded and stiff
Legume: a
dry fruit, produced from a single carpel, that dehisces along both sides; characteristic
of the bean family
Lenticel: a
porous structure in bark that permits gas exchange through the otherwise
airtight cork; may be a slit or a small bump
Ligule: a
strap-shaped organ; in the composite family, the flattened corolla of a ray
floret
Limb: in
a petal with a narrowed base (claw), the wider, spreading apical portion; in a
fused corolla with a tubular base, the widened upper portion
Linear:
very narrow with parallel margins
Lobate:
having lobed margins
Lobe: of
leaves, a division or protrusion too large to be considered a tooth, often
rounded; of a calyx or corolla that is fused basally, the upper free portion of
a sepal or petal
Locule:
the hollow chamber within an ovary that contains ovules; a simple carpel has
only one locule, while compound ovaries (formed by the fusion of several
carpels) may have one large locule or may be divided into single locules
Loculicidal: of
a capsule, splitting open in the middle of locules, in contrast to splitting
along the septa between locules (i.e., septicidal)
Margin:
the outside edge of a leaf, sepal, petal, etc.
Medullary
rays:
rays of parenchyma that separate vascular bundles in a stem, also called pith
rays
Mericarp: a
single-seeded, separately dispersed segment of a schizocarp, derived from a
single carpel, as in the carrot family
Mesocarp:
the middle layer of a fruit wall, the layer that becomes thick and fleshy in
berrylike fruits
Micropyle: a
pore or opening in the coat of a seed, the point of entrance of the fertilizing
pollen tube
Microspecies: in
confusing variable genera, a form or population that has been given a species
name but is at best marginally distinct
Midrib:
the central vein in a leaf, running from the base to the apex, usually larger
than other veins
Monoecious:
having unisexual flowers, with both sexes borne on the same plant, often in
separate inflorescences (compare to dioecious)
Mucronulate:
having a minute bristlelike narrow point at the tip
Nectary: a
structure that produces nectar, usually but not always inside the corolla of a flower
Node: a
point on a stem at which one or more leaves and/or branches are produced
Nothospecies: a
plant of hybrid origin that is named and treated as a species
Nutlet: in
plants such as mints with a gynobasic style, a small dry fruit derived from one
of the lobes of the ovary
Obcordate:
heart-shaped, with the broad notched end basal
Obdeltoid:
broadly triangular, with the base being one of the points
Oblanceolate:
like lanceolate, but with the broadest portion above the middle
Oblique: of
a leaf base, asymmetrical, often with one side tapering to narrowly rounded and
the other side rounded to cordate
Oblong:
somewhat rectangular, with straight parallel sides, and the breadth at, above,
and below the middle nearly equal
Obovate:
like ovate, but broadest above the middle
Obtuse:
having a blunt apex, forming a point with an angle of >90°, or somewhat
rounded
Opposite: of
leaves, borne two per node on opposite sides of the stem
Orbicular:
roughly circular in outline, as broad as long
Ovary:
the lowest part of a carpel or pistil, containing one or more ovules
Ovate:
egg-shaped, broadest below the middle
Ovoid:
egg-shaped, referring to a three-dimensional structure
Ovule:
structure inside an ovary that develops into a seed after the egg cell borne
inside is fertilized
Paleae:
bracts borne on the receptacle of a composite head (capitulum), subtending
individual disk florets
Palmate: of
leaflets, leaf lobes or veins, arising radially from the base like fingers from
a hand
Panicle: a
branching inflorescence with the lower flowers maturing first (compare to a
raceme, which is not branched)
Papilla: a
small bump or wart on the epidermis
Papillate:
bearing papillae
Pappus: in
composite florets, a modified calyx that may be present at the top of the ovary
and persisting on the fruit, usually consisting of one or more whorls of
bristles, a scale, or a small ring of tissue (e.g., the fluffy portion of a
dandelion “seed”).
Parenchyma:
soft, thin-walled, unspecialized plant tissue
Pedicel: a
stalk on which a single flower is borne
Peduncle:
the stalk or stem on which an inflorescence is borne
Pellucid:
transparent, clear, like some leaf glands
Peltate: of
leaves or trichomes, umbrella-like in shape with the stalk attached not at the
edge, but on the lower surface
Pepo:
characteristic fruit of the cucumber family, derived from an inferior ovary,
with a tough rind, fleshy mesocarp, and numerous seeds
Perennial: a
plant that normally lives for at least three years
Perfect: of
flowers, possessing both male and female parts; also called bisexual or
hermaphroditic
Perianth:
collectively, the calyx and corolla, including all sepals and petals or all
tepals
Pericarp:
fruit wall, including all layers of tissue derived from the ovary
Pericycle: in
roots, a small amount of parenchyma found at the outside of the initial
vascular cylinder; in older and larger roots, the pericycle may give rise to a
large cortex-like ring of parenchyma between the vascular tissue and the bark
(“secondary cortex”)
Petaloid:
resembling a petal, often colorful
Petiole: a
stalk on which the blade of a leaf is borne
Petiolule:
the stalk of an individual leaflet in a compound leaf
Phloem:
nonwoody vascular tissue that transmits sugars downward; in large woody stems
or roots, a ring of secondary phloem is produced outside the secondary xylem
(wood); in woody stems, secondary phloem is the innermost layer of the inner
bark
Phyllary: in
the composite family, a bract in the involucre subtending the entire capitulum
(contrast with palea, a bract borne on the capitulum’s receptacle and
subtending a single floret)
Pinnate: of
compound or lobed leaves or leaf venation, feather-like with a single main
axis, with leaflets, lobes or smaller veins emerging at points along the axis
and extending laterally
Pinnatifid: of
a leaf, deeply pinnately lobed or cleft, but the clefts between lobes not
reaching the midrib
Pinnatisect: of
a leaf, pinnately lobed with the clefts between lobes extending to the midrib,
but the lobes not forming clearly separate leaflets as in a pinnately compound
leaf
Pistil:
the entire gynoecium where multiple carpels are fused together, or the only
carpel in a unicarpellate gynoecium
Pith: an
area of soft parenchymatous tissue inside the vascular tissue at the center of
a stem or rhizome, or rarely a root
Ploidy:
the number of copies of each chromosome within a single cell, e.g., diploid (2
copies, as in almost all higher animals), tetraploid (4 copies), or hexaploid
(6 copies); plants of different ploidy levels usually cannot reproduce
successfully, so change in ploidy often results in speciation
Plumose:
with long, soft pinnately branching bristles that give a feathery appearance
Prickle: a
sharp outgrowth of the epidermis of a stem, as in roses
Primary
venation: the midrib of a pinnate-veined leaf or the few main
veins arising from the base of a palmate-veined leaf
Prostrate: of
a stem, creeping along the ground, sprawling
Proximal: of
the end of a part or organ that is closest to its attachment to the rest of the
plant (contrasted with distal)
Pubescent:
bearing hairs (trichomes); sometimes refers especially to short, soft hairs
Punctate:
dotted with round depressions or glands
Pyrene: a
pit or stone of a drupe, consisting of a hard layer of fruit tissue (endocarp)
surrounding a single seed
Raceme: an
unbranched inflorescence with pedicellate flowers, the lower flowers maturing
first (compare to a panicle, in which the rachis is branched, or to a spike, in
which the flowers are sessile)
Rachis:
the central stalk of a compound leaf or the stalk of an inflorescence above the
point of attachment of the first leaflets or flowers
Radially
symmetrical: divisible into equal, mirror-image halves
along multiple planes, as in a roundish flower with all petals of equal size
and shape; also called actinomorphic or regular
Radicle:
the part of an embryo that will develop into the primary root
Ray
floret: in the composite family, a floret with an asymmetrical,
flattened corolla resembling a single petal, often borne only near the edge of
the receptacle of a head; also called ligulate florets
Receptacle:
the tissue at the base of a flower from which the perianth and sexual organs
arise; in composite heads, the knob of tissue at the end of the peduncle on
which the florets are borne
Reflexed:
bent backward or downward, e.g., petals that curve toward the pedicel
Reniform:
kidney-shaped
Reticulate: of
leaf veins, net-like or forming a network
Revolute: of
leaf margins, inrolled or folded over toward the underside, somewhat like a
tiny hem
Rhizome: an
underground stem, often resembling a root
Rhomboid:
diamond-shaped, with obtuse angles at the sides and acute angles at the base
and apex
Rosette: a
whorl of leaves arising at ground level
Rotate:
especially of a fused corolla, disk-shaped or wheel-shaped
Samara: a
dry, indehiscent, single-seeded fruit, with the fruit wall forming a wing
Scape: a
leafless peduncle arising from ground level
Scarious: of
bracts, sepal margins, etc., dry, membraneous or papery, not green
Schizocarp: a
dry fruit that at maturity splits into a number of sections (mericarps)
equalling the number of carpels that formed the gynoecium
Scutellum: in
Scutellaria, an asymmetrical protrusion on the calyx, fancied to be
shield-shaped
Secondary
venation: leaf veins arising directly from the midrib or primary
veins
Section: a
taxonomic rank below subgenus; a named portion of a genus
Sensu
stricto: in the narrow sense, if there is taxonomic controversy
about how broadly the boundaries of a species should be drawn
Septate:
divided by septa
Septum: a
partition, especially the tissue separating locules in a compound ovary
Serrate:
having sharp, forward-pointing teeth like a saw blade
Serrulate:
serrate, with the teeth small
Sessile: of
a leaf or flower, borne directly attached to a stem rather than elevated on a
petiole or pedicel
Seta: a
very short bristle
Silicle:
characteristic of the mustard family, a dry, dehiscent fruit, flattened with a
central membrane (replum) to which seeds are attached, which persists after the
outer wall of the fruit falls away; if fruit length is more than double the
breadth, it is called a silique
Simple: of
leaves, trichomes, etc., not compound or branched
Sinuate:
with strongly wavy margins
Solitary: of
flowers, borne singly
Spatulate: of
leaves, spoon-shaped, rounded at the apex and tapering to a narrow base (e.g.
dandelion)
Spike: an
unbranched inflorescence with sessile flowers, the lower flowers maturing first
Spreading:
extending at right angles to a main axis, e.g., petals extending straight
outward from the center of a flower
Stamen: a
male reproductive organ, usually consisting of a sterile stalk (filament) and a
fertile anther
Staminode: a
sterile stamen, sometimes modified to serve some other function, or simply
reduced in a female flower
Stele:
the central cylinder of vascular tissue, including xylem and phloem, in a stem
or root
Stellate:
star-shaped; of hairs, branching, with each hair having several arms, giving a
bushy appearance
Stigma:
the receptive tissue at the top of a carpel or pistil, where pollination occurs
Stipe: a
stalk on which a plant organ is elevated, e.g., raising the ovary above the
receptacle
Stipules: a
pair of small bractlike or leaflike structures borne at the base of a petiole
in some flowering plants
Stolon: a
horizontal, creeping stem that produces roots at nodes
Striated:
bearing parallel lines not conspicuous enough to be called ridges
Style: a
stalk by which the stigma is often elevated above an ovary
Stylopodium: in
fruits of the carrot family, a disk-shaped enlargement of the base of the
style, visible at the top of the fruit
Sub-:
prefix indicating subordinate rank when preceding a taxonomic rank (e.g.,
subfamily), indicating “almost” or “nearly” when preceding an adjective (e.g.,
subsessile)
Subgenus: a
named portion of a genus; a taxonomic rank between genus and section, so that
one subgenus may be divided into multiple sections
Subglobose:
almost spherical
Suborbicular:
almost round
Subsessile:
almost sessile, sometimes with very short petiole or pedicel
Subspecies: a
named portion of a species that is genetically or morphologically distinctive
and geographically separated from other subspecies; of a higher rank than
variety, so that one subspecies may be divided into multiple varieties
Tepal:
individual unit of a perianth in which there is only one whorl of parts, or in
which sepals and petals are identical (as in a tulip)
Terete:
cylindrical, circular in cross-section
Terminal:
borne at the end of a stem (contrast to lateral, borne at the side of a stem,
often emerging from a leaf axil)
Ternate:
divided into threes, especially of compound leaves
Tertiary
venation: leaf veins arising from secondary veins; tertiary and
higher-order veins are usually smaller and weaker than primary and secondary
veins
Thyrse: a
dense panicle with cymose branches
Trichome:
hair; an outgrowth of the epidermis, single-celled or multicellular, sometimes
bearing a gland
Trifoliolate:
with three leaflets (also “trifoliate”)
Truncate: of
a leaf apex or base, broad and flat, as if cut off
Tuber: a
thickened underground stem serving as a storage organ (such as a potato)
Tubercle: a
small warty protrusion
Tubular: of
a fused calyx or corolla, forming a narrow cylinder
Umbel: an
inflorescence with the petioles of all flowers radiating from a single point at
the end of the peduncle
Umbellet:
the terminal umbels of a compound umbel
Undulate:
wavy-margined, but not so much as sinuate
Unisexual: of
a flower, having fertile parts of only one sex
Vallecula: in
fruits of the carrot family, the area between two longitudinal ribs on the
dorsal surface; usually sunken in dried fruit, forming a “little valley”, but
often shallow in fresh or rehydrated fruit
Valve: a
split in a capsule-like fruit that allows seeds to escape; in multilocular
fruits, there is normally one valve per locule
Verticillaster: characteristic
of the mint family, an inflorescence of condensed axillary cymes that appears
to be a dense whorl of flowers at a node
Verticillate:
whorled
Vitta: in
fruits of the carrot family, an oil tube running longitudinally through the
fruit wall; vittae are usually found in the valleculae between ribs on the back
side and in the commissural face
Whorl: a
ring of parts borne at about the same level on a stem or receptacle
Whorled: of
leaves, having three or more borne at each node
Xylem:
water-transporting tissue; secondary xylem in stems and roots forms wood
Inflorescence Types PDF
Leaf Types PDF
