P. coronopus may behave as an annual, a biennial or a perennial. The plant can develop axillary offsets, hence reproducing vegetatively. A rosette of leaves develops, remaining flat or largely close to the soil. Leaves are up to 20 cm long by 2 cm wide, variously entire or shallowly or deeply toothed, somewhat pubescent. Under saline conditions the leaves may show distinct succulence. Flowering stems are numerous from each rosette, up to 20 cm high, carrying a dense spike of flowers 2-5 cm long. Each flower is subtended by a bract and consists of four sepals, the two on the posterior side conspicuously keeled and hairy. Alternating with the sepals are four whitish transparent petals. The flowers are normally hermaphrodite, having four stamens with long filaments, and large yellow versatile anthers and a syncarpous ovary surmounted by a long, hairy simple style. However, male sterility does occur. The capsule has two lower chambers with two seeds each, while there is usually an upper chamber containing a single smaller seed. The larger seeds are black, shiny, boat-shaped and 1.0-1.5 mm long (mean weight 0.20 mg) while the smaller are 0.7-0.9 mm long (mean weight 0.13 mg). The larger seeds are released when the capsule dehisces, while the smaller seed is usually retained (Rowling, 1933).
Related invasive species
- Plantago coronopus
Related Farm Practice
- Soil
In its native range of Europe, northern Africa and Central and West Asia, P. coronopus is an inoffensive low-growing herb in coastal saline situations. It is rarely a weed of crops though Holm et al. (1979) list it as a ‘common’ weed in Spain. In recent years, however, it has been recorded as invasive in Australia and in California, forming dense mats which displace native vegetation, including endangered species in California (Weber, 2003;United States Fish and Wildlife Service, 2008a, b). Furthermore, it is reported as a weed problem in non-tilled orchards, irrigated pastures, and alfalfa and clover fields in California.
In California, USA, P. coronopus is a weed problem in non-tilled orchards, irrigated pastures, and alfalfa (Medicago sativa) and clover (Trifolium spp.) fields. It is also reported as a threat to two endangered plant species in California;Trifolium amoenum (US Fish and Wildlife Service, 2008a) and Astragalus robbinsii var. jesupii (US Fish and Wildlife Service, 2008b).