F1

First filial generation, the immediate offspring of cross-fertilisation. A term used commercially to designate a generation of seed or resulting plants which does not transmit all its desirable characteristics and can be obtained only by a repetition of the cross

F2

Second filial generation, arising from the intercrossing or self-fertilisation of an F1 generation

Fastigiate

With branches erect and close together

Fertile

Of stamens producing good pollen or fruit containing good seeds, or of stems with flowering organs

Fibrous roots

Roots which are relatively thin, much branched throughout and have ample fine growth

Filament

Stalk of a stamen

Florets

Small, individual flowers of a dense inflorescence