Glossary - Westcott's Plant Disease - page 694

Fasciation . Joining side by side; a plant disease
with flattened and sometimes curved shoots.
Fascicle . A small bundle or cluster.
Filiform . Threadlike.
Fimbriate . Fringed, or toothed.
Flag . A branch with dead leaves on an otherwise
green tree.
Flagellum , pl. Flagella . Whiplike organ on
a motile cell; cilium.
Fruiting Body . Fungus structure containing or
bearing

Haustorium , pl. Haustoria . Special hyphal
branch extended into living cell for purpose
of absorbing food (Fig. 1, p. 286).
Heteroecious . Undergoing different parasitic
stages on two unlike hosts, as in the rusts.
Heterothallic . Of a fungus, sexes separate in dif-
ferent mycelia.
Holocarpic . Having all the thallus used for

a fruiting body.
Homothallic . Both sexes present in same

spores; mushroom, pycnidium, mycelium.

Host . Any plant attacked by a parasite.
Hyaline . Colorless, or nearly transparent.
Hymenium . Spore-bearing layer of a fungus
fruiting body.
Hyperplastic . Term applied to a disease produc-
ing an abnormally large number of cells.
Hypha , pl. Hyphae . Single thread of a fungus
mycelium.
Hypoplastic . Term applied to a disease with
subnormal cell production.
Hyphopodium , pl. Hyphopodia . More or less
lobed appendage to a hypha.
Hysterothecium . Oblong or linear perithecium,
sometimes considered an apothecium, open-
ing by a cleft.
Immune . Exempt from disease; having qualities
that do not permit infection.
Immunization . Process of increasing the resis-
tance of a living organism.
Imperfect Fungus . One lacking any sexual repro-
ductive state.
Imperfect State . State of life-cycle in which asex-
ual spores, or none, are produced. See
Anamorph.
Incubation Period . Time between inoculation
and development of symptoms that can be
seen.
Indehiscent . Of fruit bodies, not opening, or with
no special method.
Infection . Process of beginning or producing
disease.
Infection Court . Place where an infection may
take place, as leaf, fruit, petal, etc.
Injury . Result of transient operation of an adverse
factor, as an insect bite, or action of
a chemical.
Innate . Bedded in, immersed.

perithecium, apothecium, etc.
Fumigant . A volatile disinfectant, destroying
organisms by vapor.
Fungicide . Chemical or physical agent that kills
or inhibits fungi.
Fungi Imperfecti . Fungi that have not been
connected with the perfect or sexual stage;
most are imperfect states of Ascomycetes.
Fungistatic . An agent preventing development of
fungi without killing them.
Fungus , pl. Fungi . An organism with no chloro-
phyll, reproducing by sexual or asexual
spores, usually with mycelium with
well-marked nuclei.
Fusiform . Spindle-like, narrowing toward the
ends.
Fusoid . Somewhat fusiform.
Gall . Outgrowth or swelling, often more or less
spherical, of unorganized plant cells as result
of attack by bacteria, fungi, or other organisms.
Gametangium . Gamete mother cell.
Gamete . A sex cell, especially one formed in
a gametangium.
Germ Tube . Hypha produced by a germinated
fungus spore.
Gill . Lamella or hymenium-covered plate on
underside of cap of a mushroom.
Girdle . A canker that surrounds stem, completely
cutting off water supply and thus causing
death; girdling roots also cause death.
Glabrou s. Smooth.
Gleba . Sporulating tissue in an angiocarpous fruit
body.
Globose . Almost spherical.
Gram - negative , Gram - positive . Not being
stained, and being stained, by the Gram stain
used in classifying bacteria.