Fennel fruits are oblong, 4-6 mm long, 1.5-2.2 mm wide, with 5 main ribs, sharp; vittae 1 in each furrow, vittae 2 in the commissure; endosperm ventral surface nearly flat or slightly concave. Fl. May-Jun, fr. Jul-Sep.
Perennial, cultivated as one or two years old. The whole plant has a special pungent flavor, and the surface has white powder. Leaves pinnately divided, segments linear. Yellow flowers in summer, compound umbels. Fruit oval, yellowish green. Prefer warm, suitable for sandy loam soil; avoid planting in clay soil and too wet place. Spring and fall can be sown or spring planting propagation. Native to the Mediterranean region, China is widely cultivated throughout the country, strong adaptability.
China's northern main spring and fall cultivation. (Open field cultivation) spring sowing: March to early April, May mid and late harvest. Fall sowing: July to August, harvested in September. The fruit is a double-hanging fruit, cylindrical, some slightly curved, slightly pointed at both ends, 4-8mm long, 1.5-2.5mm in diameter, with a yellow-green or yellowish surface, a yellowish-brown protruding stigmatic base remaining at the tip, and sometimes a tiny fruiting pedicel at the base. The fruiting pedicel is long elliptic, with 5 longitudinal ribs on the face, and the jointed surface is flat and wider. The cross section is slightly 5-sided, and the 4 sides on the back are about equal in length. It has a peculiar aniseed odor and a slightly sweet, pungent taste.
Herb, 0.4-2 m tall. Stem erect, smooth, gray-green or pale white, much branched. Lower cauline petioles 5-15 cm long, central or upper petioles partly or wholly sheathing, sheath margins membranous; leaf blade broadly triangular in outline, 4-30 cm long, 5-40 cm wide, 4-5-pinnatisect, ultimate segments linear, 1-6 cm long, ca. 1 mm wide.
Compound umbels terminal and lateral, peduncles 2-25 cm long; rays 6-29, unequal, 1.5-10 cm long; umbellules with flowers 14-39; petioles slender, unequal; no calyx teeth; petals yellow, obovate or nearly obovate-orbicular, ca. 1 mm, with inflexed ligule at apex and 1 midvein; filaments slightly longer than the petals, anthers ovoid, pale yellow; Stylopodium conic, styles very short, forked outward or appressed to the stylopodium.