B - Gardeners' glossary A-Z - gardenersworld.com

Bacteria

Unicellular micro-organisms invisible to the naked eye, but present in every habitat. Bacteria aquire their nutrients by breaking down dead organic matter and are essential in recycling nutrients. While most bacteria are harmless or beneficial, some pathogenic bacteria cause disease.

Beard

Hairs produced on the surface of petals, found on some types of iris and a number of other plants.

Bedding plant

Any plant that's planted out in a bed, border or pot for a seasonal display, usually during spring and summer. The plants are then removed, making way for next season's display. Spring bedding is composed of spring-flowering bulbs, hardy perennials and biennials. Summer bedding plants include hardy and half-hardy annuals, tender perennials and summer-flowering bulbs.

Berry

A seed-bearing, fleshy fruit that's produced after flowering. While many berries provide valuable food, some species produce inedible and poisonous berries.

Biennial

A plant that completes its life cycle over the course of two growing seasons. The life cycle begins with germination in the spring or summer of the first season, during which stem and leaf growth occurs. The plants then overwinters, flowering in the spring or early summer of the following season. The whole cycle may be completed in less than 12 months.

Bifid

A leaf or petal cleft in two parts.

Bigeneric hybrid

A plant that originates from the hybridisation between two distinct genera. In formal plant nomenclature, this is denoted by an x before the generic name of the hybrid. The new name is derived from the names of the parent genera, ie, the resultant hybrid between amaryllis and nerine is named x amarine.

Biological pest control

A means by which a selected natural mechanism (eg, parasitism, predation, disease) is used to control pests. Has the advantage of minimising the legal, health and environmental hazards associated with chemical control.

Bipinnate

Pairs of small leaflets arranged on separate veins, which are, in turn, arranged on the midrib of the leaf. Also referred to as doubly pinnate. See Pinnate and Tripinnate.

Bisexual

Referring to flowers that bear both male (androecium) and female (gynaecium) reproductive parts.