SPECIES DESCRIPTION
SISYMBRIUM IRIO

Family and Genus:- See- CRUCIFERAE

Common Names:- London rocket

Homotypic Synonyms:- Crucifera irio, Descurainia irio, Erysimum irio,
Norta irio.

Meaning:- Sisymbrium (Gr) An ancient Greek name for various plants.
                  Irio (L) The name in Pliny for a cruciferous plant.                  
                
General description:- Herbaceous annual.

Stems:-
1) Up to 60 cm, glabrescent or with long, curved hairs.

Leaves:-
1) Lower, sinuate-pinnatifid, the terminal lobe larger than the laterals.
2) Cauline, lobed or entire and hastate, shortly petiolate.

Flowers:-
1) Inflorescence, condensed, the young siliquae overtopping the flowers and buds.
2) Petals, 25-3 5(-6) mm;
3) Pedicels, 3-6 mm in flower, up to 20 mm in fruit.
4) Anthers, c. 07 mm.
5) Style, 03-07 mm.

Fruit:-
1) Siliqua, 25-65 x 07-12 mm, torulose;  septum more or less hyaline.
2) Seeds, 07-11 mm.

Key features:-
1) At least the lower leaves deeply lobed or divided.
2) Petals, less than 3 mm, shorter than or only slightly exceeding the sepals.
3) Pedicels, 3-6 mm in flower, up to 20 mm in fruit, and much thinner than the
    siliqua; rarely more than 05 mm diam at the base.
4) Anthers, c. 05 - 07 mm.
5) Inflorescence, very contracted, the young siliquae distinctly overtopping the
    flowers and buds.

Click here for a glossary of terms used.

Habitat:- Stony and rocky places, field margins, roadsides, wasteground and
coastal habitats, 0-600 m.

Distribution:- Widespread throughout the Mediterranean region and SW Asia.
limited occurrence on Crete, known from a few coastal areas.

Flowering time:- Mid-Mar to early June.

Photos by:- Steve Lenton