The Maltese stocks is endemic to our islands, just like our national plant (the Maltese centaury – Widnet il-baħar). It is in fact known in Maltese as Ġiżi ta’ Malta because it is not found growing wild in any other country.

The plant, which is not considered to be a separate species but a subspecies, flowers from March to May. Another sub-species which is not indigenous to the Maltese islands, the garden stocks (Ġiżi komuni), was introduced in Malta as a garden plant but can be found growing wild in a number of areas, especially on the fortifications at Valletta, Floriana, Tigné and Manoel Island.

This Maltese plant was first described by a local and two foreign botanists in 1988.

It is a perennial plant be-longing to the mustard family and is very rare on the island but less so in Gozo. It is an endangered species and is protected by law.

Meanwhile, Mediterran-ean stocks, known in Maltese as Ġiżi tal-baħar, is an annual plant with pale violet flowers.

Until 20 years ago, it grew mostly in disturbed ground along the extreme east coast of Malta but has now spread to other areas especially along the Sliema, San Ġiljan and Baħar iċ-Ċagħaq coast and is more common than it used to be.

The increase in range probably started with the dispersion of the seeds when a strong east wind blew them across the Grand Harbour to the other side of the Valletta peninsula from where it continued to expand its range further west.

This species has an interesting mode of dispersion as, when the seeds become ripe, the plant breaks off at the base and tumbles in the wind leaving a trail of seeds along the way.

Another species is the night-scented stocks (ġiżi tal-lejl) which is non-indigenous and rare.

This species is of Eurasian origin and is often grown in gardens, especially in cooler regions, mainly for its pleasant scent which is most noticeable during the evening and at night.