AgroForestryTree Database
Glossary J-L
kilning
Drying wood under controlled temperature and humidity.
lacerate (of leaves)
Irregularly cut.
lamina
The thin, flat blade of a leaf or petal.
lanceolate
Narrow, as a lance, with tapering ends.
lateral
Situated at side; a side extension as of a branch or shoot.
laterite
An iron-rich subsoil layer found in some highly weathered humid tropical soils that, when exposed and allowed to dry, becomes very hard and will not soften when rewetted. When erosion removes the overlying layers, the laterite is exposed and a virtual pavement results.
laterite soils
Soil groups found under tropical forest in humid conditions, characterized by a low silica sesquioxide ratio of the clay fraction, low base-exchange capacity, low clay activity, low content of most minerals and high stability; often red.
latex
1. A thick white or whitish liquid produced by certain plants. For example, Antiaris toxicaria and Bridelia micrantha both have a latex sap. A more popular example is the rubber tree (Hevea brasiliensis). Some types of latex can be harmful, especially if the latex gets into the eyes.
laticiferous
Producing a milky juice (latex).
layering See also air-layering
1. The production of adventitious roots from a prostrate main stem or a branch in contact with the ground, enabling a potentially separate plant to be formed.
2. The rooting of an undetached branch or stem lying on or partially buried in the soil, or enclosed in other media, which is capable of independent growth after separation from the mother plant.
leached soil See also leaching
A soil where most soluble materials have been removed from the entire profile or removed from the upper layer and accumulated in a lower layer.
leaching
The washing out of material from the soil, both in solution and in suspension.
leaf
An aerial and lateral outgrowth from a stem which makes up the foliage of a plant. Its prime function is to manufacture of food by photosynthesis. It typically consists of a stalk (petiole) and a flattened blade (lamina).
leaf blister
Leaf spot or blotch that is swollen or raised, so that the area appears blister-like on the upper surface of the leaf.
leaf blotch
Dad area on the leaf that often diffuses into healthy tissues.
leaf retaining See also evergreen
Applied to a plant whose leaves remain for more than one season.
leaflet
Each separate lamina of a compound leaf.
leaf spot
A dead area on the leaf well defined from healthy tissue.
legume
A pod-bearing member of the Fabaceae family, one of the most important and widely distributed plant families (now split into Papilionaceae, Mimosaceae and Caesalpiniaceae). Included are many valuable food and forage species, such as peas, beans, peanuts, clovers, alfalfas, sweet clovers, lespedezas, vetches and kudzu. Not all legumes are nitrogen-fixing plants, for example, many of the Caesalpiniaceae do not form nodules.
lenticel
A pore in the stem of a woody plant, appearing as a raised spot that may be filled with a powdery substance. The pore permits air to reach tissues below the surface.
lesion
Area of dead tissue.
liana
Vine-like climbing plant that grows by supporting itself on others and that roots in the ground, germinating there and maintaining its contact with the soil (also spelled 'liane').
lift pruning See also pruning
Removing the lower branches of trees being grown for timber, to elevate the crown and to obtain a better quality, knot-free log. For example, as with Pinus radiata grown in pasture in New Zealand and Australia.
ligulate
Strap-shaped or tongue-shaped.
ligule (of flowers)
A scale-like membrane on the surface of a leaf; the strap-shaped corolla in some Compositae.
limb See also tube
The upper, expanded portion of a calyx or corolla with fused parts.
lime
In strict chemical terms, calcium oxide. In practical terms, a material containing carbonates, oxides or hydroxides or both. Used to neutralize soil acidity.
line thinning See also mechanical thinning
Removing specified rows of trees in a plantation, such as every 4th row.
linear (of leaves)
Elongated, and with parallel sides.
lithophyte
A plant which grows on stones and not in the soil.
litter
Uppermost layer, on the soil surface, of loose organic debris (for example, as in forests), consisting of freshly fallen or slightly decomposed organic materials.
live fence See also hedge, hedgerow
A way of establishing a boundary by planting a line of trees and/or shrubs (the latter usually from large stem cuttings or stumps), at relatively close spacing and by fixing wires to them. If animals are to be kept in or out, more uprights (dead sticks) can be tied to the wires. Also called a 'living fence'.
loam See also soil texture
Soil containing a relatively equal mixture of sand and silt and somewhat smaller proportion of clay; generally a desirable quality. May be subdivided into texture classes like 'sandy loam', 'silt loam' and 'clay loam'. Specifically, soil material containing 7-27% clay, 28-50% silt, and less than 52% sand.
lobe (of leaves or perianths)
A curved or rounded part.
lobed (of leaves)
With curved or rounded edges.
locule
The chamber or cavity of an ovary which contains the ovules, or of an anther which contains the pollen.
loculicidal
Splitting open longitudinally along the dorsal suture (mid-rib) of each segment of the wall.
loess
Mainly silt, transported and deposited by wind.
log
The part of the trunk suitable for use as timber.
long shoot
Where there is shoot dimorphism, an extended shoot contributing to the architecture of a tree.
long-day plant
A plant whose development is affected by photoperiodism, in particular where a process (for example, flowering) is promoted if the plant is subjected to day lengths and a critical length and thus to night lengths below it.
long-term storage
The storage of accession for long-term periods (a decade at a minimum, but such stores may expect satisfactory storage for 50-100 years or more).
longevity
Long life, long duration of existence.
lop
To cut off one of more branches of a tree, whether standing, felled or fallen.
lopping See also pruning
1. Cutting one or more branches of a standing tree, for example, for fuel or fodder.
2. A technique used to collect fodder for animals by cutting side branches, not the main stem. Animals can be allowed to eat the lopped branches of the tree, or the branches can be carried to the animals as in a zero-grazing system.
lumber See also timber
Sawn timber. A unit of measure is the 'board foot', that is, a board 150 cm long by 150 cm wide by 10 cm thick.
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