Host Plants - Westcott's Plant Disease - page 421

Host Plants

Headings Under Which Diseases Are
Described

L EAF B LISTER ,L EAF C URL D ISEASES - leaf
deformities.
L EAF S CORCH - discoloration as if by intense heat.
L EAF S POTS - delimited dead areas in leaves.
L ICHENS - occasional on trees, or shrubs.
M ISTLETOE - semiparasitic seed plant, forming
leafy tufts in trees.
M OLDS - conspicuous fungus growth on leaves,
seeds, or grafts.
N EEDLE C ASTS - conspicuous shedding of ever-
green foliage.
N EMATODES - causing decline diseases and
flowers.
N ONPARASITIC D ISEASES - due to environmental
conditions rather than specific organisms.
P OWDERY M ILDEWS - superficial white felty or
powdery growth on leaves and flowers.
R OTS - soft or hard decay or disintegration of
plant tissues.
R USTS - with reddish or

A NTHRACNOSE - dead spots with definite margins,
often with pinkish slimy spore masses, on
leaves, stems, or fruit.
B ACTERIAL D ISEASES - all types of diseases, galls,
blights, rots, leaf spots, caused by bacteria.
B LACK K NOT - black, knotty enlargement of
woody tissue.
B LACKLEG - darkening at the base of a plant.
B LACK M ILDEW - superficial dark growth caused
by parasitic fungi.
B LACKSPOT - a dark leaf spot on rose.
B LIGHTS - general killing of leaves, flowers, stems.
B LOTCH D ISEASES - irregular necrotic areas on
leaves or fruit.
B ROOMRAPES - leafless herbs parasitic on roots.
C ANKERS A ND D IEBACK - localized lesions on
stems or trunks, sometimes accompanied by
dying back from the top.
C LUB R OOT - distorted swollen roots.
D AMPING -O FF - sudden wilting of seedlings or
rotting of seeds in soil.
D ODDER - parasitic seed plant with orange
tendrils.
D OWNY M ILDEWS - with internal mycelium but
fruiting structures protruding to form white,
gray, or violet patches.
F AIRY R INGS - mushrooms growing in circles.
F RUIT S POTS - blemishes on fruit.
G ALLS - noticeable enlargements of

rust-colored spore

masses.
S CAB - raised or crustlike lesions on leaves or
fruit.
S CURF - flaky or scaly lesions.
S LIME M OLDS - found in lawns.
S MUTS - with sooty black spore masses.
S NOW M OLD - light patches in turf, especially
early spring.
S OOTY M OLD - superficial black mycelium grow-
ing in insect exudate.
S POT A NTHRACNOSE - light spots with raised
darker borders or scabby lesion caused by
Elsino ¨ species.

leaves,

stems, or roots.