AgroForestryTree Database
Glossary V
valvate (of perianth-segments) See also imbricate
With the margins adjacent without overlapping.
variety See also agronomic variety, cultivar, provenance
1. A taxonomic subdivision of a species based on minor characteristics and often an exclusive geographic range, or an assemblage of cultivated individuals of useful and reproducible character.
2. In taxonomy, variants of a typical species that are not known to occur as distinct populations but appear sporadically in wild stands as single or isolated individuals.
vascular
Possessing vessels; able to conduct water and nutrients.
vascular bundle
A strand of tissue involved in water and food transport.
vegetative
Not flowering. The stage of development when a plant is producing only roots, stems and leaves, that is, the vegetative organs.
vegetative reproduction
See asexual.
vein
Any of the visible strands of conducting and strengthening tissues running through a leaf.
veld
The name given to grasslands in southern Africa. Can be 'winter veld' or 'summer veld' depending on the climatic pattern, the soil and what grass species occur, hence when it can be grazed. Also spelled 'veldt'.
venation
The arrangement of the veins of a leaf.
veneer
A product made from round logs of certain trees by turning a log and slicing a continuous sheet from it. This sheet is then cut into lengths and glued to lower quality wood for making panelling, table tops, doors and other products with improved appearance.
vernation (of leaves)
The manner and pattern of arrangement within the bud.
verticillaster (of inflorescences)
Whorled dichasia at the nodes of an elongate rachis.
verticillate
Arranged in whorls.
vessels
Tube-like cells arranged end to end in the wood of flowering plants and which form the principal pathway in the transport of water and mineral salts.
viability See also orthodox seed, recalcitrant seed
1. A measure of the potential for seeds to germinate and grow. A seed of short viability will germinate well only within a short time after harvest. Some tree seeds have long viability and will germinate readily, possibly with pretreatment, long after collection.
2. The possession of life.
viable seed
Seeds that will germinate and develop into a plant, given favourable conditions, provided any dormancy that may be present is removed.
village forest garden
Larger than the homegarden, less densely planted and not so well tended. Planted with higher trees and often containing spontaneous species of herbs or lianas.
viviparous
Bringing forth live young.
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