Foeniculum vulgare

In California, fennel can be distinguished from other members of the Umbelliferae by its strong anise-like odor. Seedlings have strap-shaped cotyledons that are several times longer than wide. The first and subsequent leaves are pinnately compound into filiform divisions, as are the adult leaves.

Foeniculum vulgare seems to tolerate sandy dry soil better than fertile loam, and it seems to prefer acid rather than alkaline soil. Germination occurs within about two weeks at a temperature of 18 C. It can tolerate a range of annual precipitation from 0.3 to 2.6 m and soil pH from 4.8 to 8.3 (Simon et al. 1984).

Foeniculum vulgare has the capacity to reproduce from both its crown and its seeds. "The seeds germinate at almost any time of the year, but plants generally do not flower until 18 months to 2 years. Once a plant is established, flowering stems are produced from the perennial crown each spring. Flowering commences in May and may continue into September. Seeds are produced during the summer and autumn, and the flowering stems die back during winter to be replaced by new growth in late winter. Some stems stay alive towards the base and produce new leaves from nodes along the stems during the winter. New leaves are also produced in winter at the base of the plant" (Parsons 1973).

Dispersal of the seeds by water is of considerable importance and accounts for the occurrence of Foeniculum vulgare along watercourses. Other means of dispersal include vehicles, machinery, wool, animal skins, clothing, mud, and agricultural produce (Parsons 1973).

Reproduction by root division is common knowledge among gardeners interested in increasing their supply of Foeniculum vulgare. This adaptation allows the species to become well established and invade new areas. Occasionally, pieces of fennel crown or root are dragged by cultivation equipment or spread by earthmoving machinery into uninfested areas (Parsons 1973). More commonly, water systems will spread fennel root systems during times of high water.