Biology Reference
In-Depth Information
on lipstick vine, and on weeping fig and leaf spot
on thyme.
Coniothyrium
Cankers and Diebacks
.
Coniothyrium
▶
Cristulariella
concentricum (see
Microsphaeropsis concentrica
).
Leaf Spot
of
century plant and yucca.
Coniothyrium hellebori
Black Spot
of
Christmas rose. Large, irregular, dark brown to
black spots on both sides of leaves, often running
together with concentric zonation; many leaves
turn yellow prematurely and die; plants are weak-
ened and fail to mature the normal number of
leaves. Stems may be cankered, shrivel, and fall
over, with wilting of unopened flower buds. Open
petals sometimes have black spots. In wet
weather in spring and fall the disease can spread
through an entire planting in 2 or 3 days, but
continuous moisture is necessary for infection.
Spray with bordeaux mixture.
Coniothyrium pyrina
Leaf Spot
,
Fruit Spot
of
apple, pear.
Microsphaeropsis concentrica (formerly
Coniothyrium concentricum
).
Leaf Spot
of cen-
tury plant and yucca. Spots are zoned, light gray-
ish brown, an inch or more in diameter, with
concentric rings of tiny black pycnidia. Large
portions of leaves may be destroyed. Remove
and burn diseased leaves.
▶
Deuteromycetes, Moniliales,
Moniliaceae
Sterile hyphae decumbent; fertile hyphae hya-
line; ascending in a branched head with conidia
at tips of intermediate branches; spores globose,
hyaline, one-celled.
Cristulariella depraedans
Leaf Spot
on sugar
and other maples. Spots gray, definite or
confluent.
Cristulariella moricola
Zonate Leaf Spot
on
Halesia.
Leaf Spot
on hibiscus and tomato.
Cristulariella moricola (Telemorph,
Grovesinia pyramidalis
).
Leaf Spot
on maple,
tree-of-heaven, apple, bean, blueberry, cherry,
dogwood, hibiscus, sycamore, tung tree, vibur-
num, walnut, black walnut, beggar-ticks, trumpet
vine, Mexican tea, dayflower, blue waxweed, tick
clover, mistflower, white snakeroot, morning
glory, Indian tobacco, blue cardinal-flower, beef
steak plant, poke, smart weed, false buckwheat,
yellow dock, prickly mallow, goldenrod, catbird
grape, nectarine, grape, maple, serviceberry and
boxelder. Spots
yellow-gray with
definite
margins.
Corynespora
Cryptomycina
Deuteromycetes, Hyphomycetes
Ascomycetes, Rhytismatales
Hyphae and conidia both dark.
Corynespora cassiicola (Syn.
Helminthosporium vignicola
).
Soy Bean Target
Spot
, also on cowpea, tomato, poinsettia, vinca,
and privet; general in South. Circular to irregular,
reddish brown leaf spots, pin point to 1/4 inch,
often zonate and surrounded by yellow-green
halos. Fruit necrotic pitting and freckles are also
found on infected fruit. Dark brown spots on
petioles, pods, and seed. Variety Ogden is mod-
erately resistant. The same fungus causes reddish
purple spots on azalea, hydrangea and leaf spots
Apothecium splitting irregularly into lobes,
hyphal layer thin; spores hyaline, one-celled.
Cryptomycina pteridis
Tar Spot
of fern,
bracken. Spots are usually on lower surface and
between veins; leaves may roll.
Cryptostictis
Blights
.
▶
