Annual, biennial or perennial herbs to 2 m tall with hollow, finely ridged stems. Leaves to 30 cm long, divided 3-4 times into fine thread-like feathery segments. Leaf stalks sheathing the stem. Flower clusters branching, each of 10-40 rays and without basal bracts; spring. Flowers bisexual, yellow. Fruit about 5 mm long, ridged, slightly flattened.
A common weed of gardens, roads, railways and wasteland, especially along waterlines. In Europe, several strains of fennel have been grown for their seed flavour: Wild Fennel - bitter; Saxon or German Fennel - less bitter; Roman and Sweet Fennel - sweet. Only the sweet-seeded form appears to be in Australia and the variants are not recognised by botanical names.
var. azoricum (Mill.) Thell., Finoccio (Florence Fennel), is grown as an annual for the swollen stalk bases that are boiled and eaten as a vegetable.This is supplied to markets but rarely grown in gardens.
var. dulce Battand &Trabut. This is the variety generally encountered.
Source: (2002). Apiaceae. In: . Horticultural Flora of South-eastern Australia. Volume 4. Flowering plants. Dicotyledons. Part 3. The identification of garden and cultivated plants. University of New South Wales Press.
, Bronze Fennel. Stems and leaves with a bronze colouration, darkest at first, becoming paler. ['Bronze']