BBC Gardeners' World

Ferruginous

Rust coloured.

Fertile

Productive, having functional reproductive structures capable of bearing fruit.

Fertilisation

An essential part of sexual reproduction, involving the fusion of haploid male and female gametes to create a diploid zygote, from which a new individual develops.

Fertiliser

Any substance, organic or inorganic, used to increase soil nutrients. It can be straight, containing only one nutrient, such as nitrogen; or compound, containing more than one nutrient; or balanced, containing equal quantities of plant nutrients.

Filament

A thread-like part of the stamen, which supports the anther.

Filiform

Of leaves and other organs - very long and thin, thread-like.

Fimbriate

Fringed. Having fringed edges, as in a stigma. Fimbriate flowers have petals with divided or split edges.

Fire

1) General term for any disease or condition causing leaves to appear scorched.

2) Incurable fungal disease affecting tulips.

Fire blight

A notifiable bacterial disease of the rose family, although it may also affect apple and pear trees.

Flabellate

Leaf that is fan-shaped and semi-circular in outline.