Hortsense Glossary

Full

Term	Definition
adelgids	a family of aphid-like insects that feed exclusively on conifers and typically are covered with white waxy material.
aesthetic	has to do with appearance; beauty.
alkaline	having a basic reaction, that is containing the OH- radical and turning red litmus blue when in solution.
alternate	an arrangement of leaves or other parts not opposite or whorled; parts situated one at a node, as leaves on a stem; like parts succeeding each other singly with a common structure.
alternate host	one of two kinds of plants on which a parasitic insect or fungus (e.g., rust) must develop to complete its life cycle.
annual	maturing and living one season only.
anthers	pollen-bearing part of a stamen, borne at the top of a filament, or sessile.
anthracnose	a leaf-, stem-, or fruit-spot type of disease caused by fungi that produce their asexual spores in an acervulus.
appendages	subordinate or derivative body parts.
armyworms	caterpillar species closely related to cutworms. They often move in mass through crop stands while stripping plants of their foliage.
auricles	an ear-shaped lobe, generally used to describe the base of leaves or petals.
axils	the main stem or central support of a plant.
bacteria	a unicellular microscopic organism that lacks chlorophyll and multiples by fission.
bacterial	a unicellular microscopic organism that lacks chlorophyll and multiples by fission.
bacterium	a unicellular microscopic organism that lacks chlorophyll and multiples by fission.
basal	pertaining to the extremity of an organ by which it is attached to its support; said of leaves when at base of plant only. See rosette.
biennial	of two season's duration, normally flowering, fruiting and dying the second growing season from time of seed germination.
blight	a disease characterized by general and rapid killing of leaves, flowers, and stems.
bracts	a much-reduced leaf, often scale-like and usually associated with a flower or inflorescence.
callus	a mass of thin-walled cells, usually developed as the result of wounding or infection.
caltrop	an herb with spiny pods; I.e., puncturevine
calyx	the outer set of perianth segments or floral envelope of a flower, usually green in color and smaller than the inner set.
cambium	A one- or two-celled layer between the phloem and xylem that produces both these tissues and results in diameter growth.
canes	a long woody pliable stem rising from the ground.
canker	a necrotic, often sunken lesion on a stem, branch, or twig of a plant.
cast skins	the outer layer of an exoskeleton shed by an insect or mite and seen on leaves or twigs.
castings	fecal material; caterpillar pellets.
caterpillar	in general, the larvae of Lepidoptera; in Hymenoptera, the larva of the saw-flies.
chlorosis	of plants, fading of the color of the chlorophyll of plant leaves, caused by environmental stress, chemical deficiency, disease, insects, or mites.
chlorotic	of plants, fading of the color of the chlorophyll of plant leaves, caused by environmental stress, chemical deficiency, disease, insects, or mites.
cocoon	a covering, composed partly or wholly of silk or other viscid fiber, spun or constructed by many larvae as a protection to the pupa.
crawlers	the first stage (nymph) out of the egg of certain plant lice (scales, adelgids, etc.). This stage is quite mobile, while subsequent nymphal stages are stationary.
cultivars	an organism of a kind (as a variety, strain, or race) that has originated and persisted under cultivation.
cultivated	maintained by humans.
cutworms	caterpillar stage of the night flying "millers" or noctuid moths.
deciduous	refers to trees or shrubs that shed leaves completely at the end of the annual growth period.
defoliation	the loss of needles or leaves due to pest activity, disease, or negative environmental response.
delayed dormant	time of year when dormancy is about to end; characterized by the beginning of bud swell.
desiccation	the drying or loss of moisture from a leaf or plant part.
dieback	progressive death of shoots, branches, and roots generally starting at the tip.
dioecious	having unisexual flowers, each sex confined to a separate plant, said of species.
distorted	taking on a shape that is unnatural.
distortion	taking on a shape that is unnatural.
drought	periods or conditions that demonstrate the lack of moisture or rain.
ELISA	a test in which an antibody carries an enzyme that releases a colored compound, signifying the presence of the pathogen.
endophyte	an organism that grows within a plant.
eradicate	to do away with completely.
eriophyid	a family of tiny plant feeding mites that possess only 4 legs; they are highly host specific (feeding on only one species) and their damage is predictable and often dramatic.
evergreen	having green foliage throughout the year.
excrement	the waste products eliminated by an insect, principally from digestion; feces.
excreta	the waste products eliminated by an insect, principally from digestion; feces.
fasciation	a symptom characterized by fusing (and flattening) of such plant organs as stems.
fertile (stems)	capable of producing fruit and seed.
flag	the loss of rigidity and drooping of leaves and tender shoots preceding the wilting of a plant.
flagging	the loss of rigidity and drooping of leaves and tender shoots preceding the wilting of a plant.
flocked	covered with white cottony material so as appear like snow.
frass	solid larval insect excrement.
fruiting bodies	complex fungal structures containing spores.
fungal	referring to a group of saprophytic and/or parasitic organisms that lack chlorophyll and conductive tissues, and often produce spores. Includes molds, rusts, mushrooms, smuts, mildews, and yeasts.
fungi	saprophytic and/or parasitic organisms that lack chlorophyll and conductive tissues, and often produce spores. Includes molds, rusts, mushrooms, smuts, mildews, and yeasts.
fungus	a saprophytic and/or parasitic organism that lacks chlorophyll and conductive tissues, and often produces spores. Includes molds, rusts, mushrooms, smuts, mildews, and yeasts.
galls	an overgrowth of plant tissue.
girdled	showing mechanical damage (often from pests) to tree or shrub trunks or limbs that results in inability of cambial tissue to transport nutrients to roots.
girdling	mechanical damage (often from pests) to tree or shrub trunks or limbs that results in inability of cambial tissue to transport nutrients to roots.
gland	a general term applied to oil-secreting organs, or sometimes an obtuse projection or a ring a base of a structure.
gnarled	knotty and twisted.
growth regulator	a natural substance that regulates or interferes with growth functions in plants and insects.
grubs	an insect larva; a term loosely applied, but more specifically to larvae of Coleoptera (beetles) and Hymenoptera (wasps, etc.).
herbaceous	having no persistent woody stem above ground.
honeydew	a sweetish excretion produced by certain insects notably aphids and scales; also an exudate from the surface of some galls.
hornworm	the immature stage or caterpillar of the hummingbird or sphinx moth family; characterized by having a rhino-like horn on the tail end.
immatures	usually the larval or nymphal stages of various insect groups.
infection	the establishment of a parasite within a host.
larva	a young insect which quits the egg in an early stage of morphological development and differs fundamentally in form from the adult; in a strict zoological sense, the immature form of animals which undergo complete metamorphosis.
larvae	a young insect which quits the egg in an early stage of morphological development and differs fundamentally in form from the adult; in a strict zoological sense, the immature form of animals which undergo complete metamorphosis.
larval	a young insect which quits the egg in an early stage of morphological development and differs fundamentally in form from the adult; in a strict zoological sense, the immature form of animals which undergo complete metamorphosis.
leaflet	a foliar element of a compound leaf.
leafminer	refers to the feeding style of certain flies, caterpillars that feed between the upper and lower surfaces of leaves resulting in blotching or snake-like passages.
ligule	(1) a strap-shaped organ; (2) (in grasses) a minute projection from the top of the leaf sheath; (3) the strap-shaped corolla in the ray flowers of Composites.
lobes	a projecting part or segment of an organ as in a lobed ovary or stigma; usually a division of a lf., calyx, or petals cut to about the middle (I.e. midway between margin and midrib.
looper	a geometrid or other caterpillar in which some or all the middle abdominal legs are wanting and which moves by bringing tail to thorax and forming a loop of the intervening segments.
maggot	the legless larva of Diptera.
membranous	parchment-like texture
midge	name for certain fly families.
midrib/midvein	the primary-rib or mid-vein of a leaf or leaflet.
mildew	a fungal disease of plants in which the mycelium and spores of the fungus are seen as a powdery or downy growth on the host surface.
mutation	something qualitatively new appearing abruptly without transitional forms or slow development; a sport; a potential species.
mycelia	several hyphae, perhaps a considerable mass of hyphae, that make up the vegetative body of a fungus.
mycelium	a hypha or mass of hyphae that make up the vegetative body of a fungus.
native	inherent and original to an area.
necrosis	in a dead and decayed condition; of or pertaining to necrosis.
necrotic	in a dead and decayed condition; of or pertaining to necrosis.
needle miner	see leafminer (needle miners are only seen on conifers).
nematodes	generally, microscopic, wormlike animals that live saprophytically in water or soil, or as parasites of plants and animals.
nocturnal	of the night; applied to insects that fly or are active at night.
nodes	a joint on a stem, represented by point of origin of a leaf or bud; sometimes represented by a swollen or constructed ring, or by a distinct leaf scar.
nymphs	young insects which quit the egg in a relatively advanced stage of morphological development, differing from the adult in having the wings and the genitalia present only in an incompletely developed conditions; a young stage of insects with an incomplete metamorphosis, (e.g., stinkbugs, aphids, etc.).
oedema	a blister formation due to an increase in intercellular water in leaves.
opposite	two at a node, as leaves.
overwinters	survives the winter in a protected place in a state of physiological "shut-down".
oxalate/oxalic acid	a very strong acid. (COOH)₂
palmate	digitate, radiating, fan-like from a common point, as leaflets of a palmately compound lf. or veins or palmately-veined lf.
panicle	an indeterminate infl. whose primary axis bears branches of pedicelled fls. (at least basally so); a branching raceme.
parasites	any organisms that live in or on, or at the expense of another; organisms living in such a way as to derive all nourishment from the tissues of the host.
parasitic	referring to any organism that lives in or on, or at the expense of another; referring to an organism living in such a way as to derive all nourishment from the tissues of the host.
perennial	having a life cycle of three or more years.
petiole	a stem or stalk; the slender segment between the thorax and abdomen in certain Diptera and many Hymenoptera; in the latter, a pedicel formed of only one segment, or the first segment of a two-segmented pedicel in ants; in plants, the slender stalk of a leaf.
pheromone	chemical emitted to air currents by an insect to stimulate behavior of other members of species (e.g., mating pheromone).
photosensitive	responsive (sensitive) to light.
physiological	resulting from some unfavorable physical or environmental factor (e.g., light, temperature, water, soil nutrients, chemical, physical, or mechanical injury).
predacious	any animal that eats others; living by preying upon other organisms, as certain insects.
predators	any animal that eats others; living by preying upon other organisms, as certain insects.
predatory	any animal that eats others; living by preying upon other organisms, as certain insects.
prostrate	lying flat on the ground; a general term.
pupa	the resting inactive instar in all holometabolous insects; the intermediate stage between the larva and the adult; applied to all insect orders with complete metamorphosis.
pupae	the resting inactive instar in all holometabolous insects; the intermediate stage between the larva and the adult; applied to all insect orders with complete metamorphosis.
pupate	the resting inactive instar in all holometabolous insects; the intermediate stage between the larva and the adult; applied to all insect orders with complete metamorphosis.
regenerate	to reform; to regrow.
rhizomes	an underground stem distinguishable from a root by presence of nodes, buds or scale-like leaves.
rhizomorphs	a compact bundle of hyphae that has an outer covering and serves as a survival structure.
rosette	a crown of leaves radiating from a stem and at or close to the surface of the ground.
rosetting	short, bunchy habit of plant growth.
row covers	fine netting placed over plants to prevent insects from getting at them (e.g. Agrinet, Remay, etc.).
russet	brownish roughened areas on skin of fruit as a result of cork formation.
russetting	brownish roughened areas on skin of fruit as a result of cork formation.
rust	a disease giving a "rusty" appearance to a plant and caused by one of the rust fungi.
sanitation	the removal and burning of infected plant parts, decontamination of tools, equipment, hands, etc.
saturated	full to capacity; in soil - very wet.
sawfly	not a fly - a primitive wasp.
scab	a roughened, crustlike diseased area on the surface of a plant organ or the common name of a disease in which such areas form.
scorch	"burning" of leaf margins as a result of infection or unfavorable environmental conditions.
sepals	one of the units comprising the calyx; a usually green foliaceous element subtending the corolla.
serrations	"tooth-like" edge at leaf margin.
sheaths	any elongated, more or less tubular structure enveloping an organ or part.
shepherds crook	appears like the handle or bent end of a walking cane.
shothole	a symptom in which small diseased fragments of leaves fall off and leave small holes in their place or small holes in wood resulting from beetle boring.
silica	silicon dioxide (SiO₂)
skeletonize	feeding by certain insects which leads to the elimination of all or most of the leaf tissue - often leaving only the veins.
smut	a disease caused by the smut fungi, characterized by masses of dark, powdery spores.
sooty mold	a sooty coating on foliage and fruit formed by the dark hyphae of fungi that live in the honeydew secreted by insects such as aphids, mealybugs, scales, and whiteflies.
spikelets	(1) a secondary spike; (2) one part of a compound inflorescence which of itself is spicate; (3) the floral unit, or ultimate cluster, of a grass inflorescence comprised of flowers and their subtending bracts.
spikes	(1) a usually unbranched, elongated, simple, indeterminate inflorescence whose flowers are sessile; the flowers may be congregated or remote; (2) a seemingly simple inflorescence whose "flowers" may actually be composite heads (Liatris).
sporadic	irregular events such as insect population outbreaks that are largely unpredictable.
spores	comprised of a single gametophytic cell, it functions as the reproductive unit of fungi and some primitive plants.
stamens	the unit of the androecium and typically comprised of anther and filament, sometimes reduced to only an anther; the pollen-bearing organ of a seed plant.
sterile	barren, not able to produce seed.
stippling	the appearance of tiny white or yellow green spots on leaves resulting from mite, leafhopper, etc. feeding.
stipules	a basal appendage of a petiole, usually one at each side, often ear-like and sometimes caducous (falls of easily).
stolons	a horizontal stem that roots at its tip and there gives rise to a new plant.
succulent	bearing a thickened, juicy, soft, fleshy appearance (e.g., new leaves, or thick-leaved plants like cactus).
symptoms	the external and internal reactions or alterations of a plant as a result of a disease, insect, or mite.
systemic	spreading internally throughout the plant.
taproot	primary root that grows downward.
terminals	situated at the tip or extremity; opposed to basal.
toxic	poisonous
viability	capability of living.
viable	alive; capable of living.
viral	referring to submicroscopic obligate parasites consisting of infectious nucleic acid usually surrounded by a protein coat.
virus	a submicroscopic obligate parasite consisting of infectious nucleic acid usually surrounded by a protein coat.
viruses	submicroscopic obligate parasites consisting of infectious nucleic acid usually surrounded by a protein coat.
whorl	arrangement of three or more structures arising from a single node.
wilt	loss of rigidity and drooping of plant parts generally caused by insufficient water in the plant.
wings	(1) the lateral petal of a papilionaceous flower; (2) a dry, thin, membranous appendage.
witches' brooms	broom-like growth or massed proliferation caused by the dense clustering of branches of woody plants.
xylem	water-conducting element of a plant.