AgroForestryTree Database
Glossary N
naked (of flowers)
Lacking a perianth.
necrosis (adj. necrotic)
The death of (plant) tissue. Generally used in connection with localized death.
nectar
A sugary liquid secreted by the flowers of some plants; it forms the principle raw material of honey.
nectary
The gland in which nectar is produced.
nematocidal plant
A plant species that produces organic substances from the roots that adversely affect (kill) eelworms (nematodes). In some cases the substances produced stimulate the eelworm eggs in the soil to hatch, but the larvae are unable to infect the plant as it is resistant to them. Such plants can be grown as trap crops (for example, Tagetes spp.).
nematode
A round worm with a cuticle and a hydrostatic skeleton; often a parasite on plants or animals.
neotropics
Tropical Central and South America.
neutral soil
Neither acid or alkaline; pH 6.6-7.3.
nicking See also notching
Cutting into the stem below a bud so as to prevent it from growing out.
nitrification
The oxidation of ammonia to nitrite, and of nitrite to nitrate, by microorganisms.
nitrogen fixation
The conversion of elemental N to organic combinations or to forms readily usable in biological processes.
nitrogen-fixing plant
A plant that can assimilate and fix the free nitrogen of the atmosphere with the aid of bacteria living in root nodules.
node See also internode
1. The region of the stem where one or more leaves are attached.
2. Part of a dendrogram (diagrammatic tree). The nodes are the horizontal lines linking classes of equal rank. The internodes are the vertical lines linking each class above and below it in rank.
nodule
Nitrogen-fixing root swelling of characteristic shape and size for particular leguminous species that contain rhizobial. If the rhizobial strain is effective, atmospheric nitrogen can be fixed and is readily utilizable by the plant.
non-porous wood See also porous wood
Wood devoid of pores or vessels. Featured by all conifers and a few hardwood species.
notching See also nicking
Cutting a small wedge from the stem above a bud so as to promote its growth by preventing the flow of inhibitory hormones (indole acetic acid) from the stem apex.
numerous (of floral parts) See also indefinite
Usually meaning more than ten.
nursery stock See also stock plant
Shrub or tree species grown in a plant nursery for planting out elsewhere.
nut
A dry, single-seeded and non-opening (indehiscent) fruit with a woody pericarp.
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