Canker

Symptom; a longitudinally oriented, oval-elongated, necrotic lesion on a stem, ultimately exposing wood and often bordered by callus tissue

Brown Rot

Symptom; rot in which wood becomes brown

Brooming or Fasiculation

Symptom; abnormal proliferation or branching of plant parts, creating dense bundles or "brooms" (from single stem position)

Bleeding

Symptom; exudation of fluid from lesions

Albinism

Symptom; complete lack of pigment, dictated by genetic defect

Knot

Symptom; a bump or rough, hard gall; one of many swellings in otherwise stringy root system

Gall

Symptom; a localized swelling or outgrowth; Tumor gigantism - abnormally large plant parts

Flagging

Symptom; an isolated wilt or necrotic branch with dead leaves present

Epinasty

Symptom; abnormal, downward curving of leaf and/or petiole

Dwarfing

Symptom; failure of a plant to attain normal size and stature

Dieback

Symptom; gradual, progressive, inward-moving necrosis of various branches within the canopy; usually applied in the context of referring to wood trees and shrubs

Shot-hole

Symptom; perforation of leaves by abscission and dropping out of small spots of tissue, as a result of infection

Stunting

Symptom; lack of normal growth and enlargement of plant

Fleck

Symptom; tiny spot exhibited on typically non-woody plant tissues

Vein Banding

Symptom; usually light discoloration, outlining leaf veins

Wilt

Symptom; dropping or collapse and yellowing of a plant or plant parts

Yellows (Yellowing)

Symptom; fading of normal color pigmentation to yellow

Leaf Roll

Symptom; edges of the leaf roll or turn up; often a symptom of virus infection

Necrosis

Symptom; death of cells, tissues, organs, or entire plant

Phloem Necrosis

Symptom; death of phloem cells, often visible, caused by infection by systemic phloem pathogens such as phytoplasmas, spiroplasmas, and viruses

Ringspot

Symptom; discolored spotting, encircled by a halo or arc-like boundary/outline

Mosaic

Symptom; irregular mixing of green or yellow hues, creating a mosaic-like pattern, usually exhibited on the leaf structures of the plant

Mottle

Symptom; irregular mixing of greens and yellow; not as distinct as Mosaic

Rosette

Symptom; short, bunchy growth habit due to shortened internodes and no comparable reduction in leaf size

Rugose

Symptom; wrinkling of leaves due to swelling of the leaf tissue between veins

Rot

Symptom; physical breakdown or disintegration of tissue usually attributed to enzymatic actions of living pathogens; specific characteristics are: wet or dry, stringy, firm, fibrous, white, brown, cubical, etc.; typically the result of fungal or bacterial infection

Scab

Symptom; prominent, raised corky spots and/or bumps

Chlamydospore

Sign; thick-walled or double-walled asexual resting spore formed from hyphal cells (terminal or intercalary) or by transformation of conidial cells that can function as an overwintering stage

Cleistothecium

Sign; small, shperical, entirely enclosed ascocarp; decorated with appendages in powdery mildew fungi

Conidia

Sign; detachable spore produced openly at the tip or side of a conidiophore

Conk

Sign; papery or corky wood basidiocarp, usually protruding as a shelf from a tree trunk or log

Mildew

Sign; thin coating of mycelial growth and spores on the surfaces of infected plant parts

Mycelium

Sign; the vegetative, filamentous body of a fungus

Ooze

Sign; bacterial cells connecting together, creating a goo-like appearance; indicative of a bacterial infection

Sclerotia

Sign; compact, hard, usually dark, desicated mass of fungal mycelium; survival structure

Urediniospore

Sign; thinner-walled spores of some fungi (rusts and smuts), from which the basidium arises

Casting

Symptom; premature loss of abscised leaves or twigs

Chlorosis

Symptom; lack of chlorophyll (failure in formation) tissues; usually appear yellow or whitish; chlorotic

Color Break

Symptom; abnormally colored streaks or blotches in the flowering structure

Curl

Symptom; bending or twisting of plant parts, particularly exhibited in the leaves

Defoliation

Symptom; pathological loss of leaves; abnormally early loss is called premature defoliation or premature abscission

Uredinium

Sign; the fruiting body (sorus) of a rust fungus that produces urediniospores

Leafspot

Symptom; a plant disease lesion typically restricted in development in the leaf after reaching a characteristic size

Interveinal Leafspot

Symptom; leafspot expressed across veinal boundaries of leaf tissue

Vascular Wilt

Symptom; a xylem disease that disrupts normal uptake of water and minerals, resulting in wilting and yellowing of foliage