Xanthium strumarium L.

Code

XANST

Growth form

broadleaf

Biological cycle

annual

Habitat

terrestrial

Algeria: Xanthium strumarium germinates in late spring and summer; flowering takes place from June to October.
Brazil: Fruiting is very dependent on the photoperiod. The plant does not flower when the days are long, and fruiting only begins in autumn when the days become shorter. Plants that germinate late in the season may flower and set fruit even though they are only 10 cm tall.
China: X. strumarium flowers from July to August and bears fruit from September to October.
Madagascar: Xanthium strumarium is an early cycle species with fast growth; it flowers and fruits at the beginning of December till end of February
New Caledonia: This annual plant reproduces by seeds that have the characteristics of not germinating at the same time, some at the next rainy season, others remain dormant. Fruits are adapted to be carried by clinging to animals. They are also found in the gravel taken from rivers. Fruits can also float. Germination takes place in the beginning of the rainy season, growth is rapid and new fruits are produced in the month of March. The plant dies in the dry season.

Xanthium strumarium is an ectozoochorous species.

Xanthium strumarium can easily be confused with X. orientale var. italicum. These two species are quite similar at the vegetative stage, but differ mainly at the fruiting stage. X. strumarium has leaves with a slightly cordate base, and a fruiting involucre 8 to 18 mm long and 6 to 12 mm in diameter (including spines) with lateral spines shorter than the diameter of the fruit and straight apical tips 2.5 to 4 mm long, whereas X. orientale var. italicum has leaves that are generally wedge-shaped at the base and a larger fruiting involucre 17 to 25 mm long and 7 to 15 mm in diameter with lateral spines as long as the diameter of the fruit and straight, divergent apical tips 5 to 12 mm long.

Xanthium strumarium is a C3 species.

Xanthium strumarium grows on the banks of rivers or in dry riverbeds, along beaches and in flood plains on damp sandy soil, is a ruderal species in villages and along roadsides and a weed in cultivated plots, wasteland and grassland on heavy, damp clay soils.  It thrives on moist or seasonally wet alkaline soils, from sea level to altitudes of 2,000 m. It is found mainly in temperate regions, but also in subtropical and Mediterranean climates. It prefers open communities and disappears if it is in the shade or in a situation of strong competition.

Algeria: Xanthium strumarium is a fairly common species in various summer annual crops (especially market gardening) and perennial crops (especially citrus groves), as well as along irrigation canals in the north of the country, as confirmed by the profusion of vernacular names. Preference for filtering, sandy to silty-sandy soils, fairly rich in nitrogen.
Brazil: Xanthium strumarium is a fairly common species in the southern and south-eastern regions of Brazil. It is a weed that can be invasive in annual crops grown in moist soil.
Camargue - France: X. strumarium is a ruderal nitrophilous species, abundant in areas frequented by cattle, wasteland and pastures.
China: X. strumarium is a common weed that develops in wet or seasonally wet, often alkaline soils. It thrives on wasteland and at the edges of agricultural plots.
Madagascar: Xanthium strumarium grows on ferralitic soils, more or less humiferous, rich, in sunny places. It is a weed of maize and semi-intensive vegetable cultivations. It is also present in the waste land around the houses, roadsides and in cultivated plots in the regions of the central highlands and the Middle East.
Morocco: Xanthium strumarium is a fairly common species. It grows in crops, fallow land and pastures on fairly damp sand.
South Africa: X. strumarium can be very abundant on the banks of watercourses, especially in the Kruger National Park.
West Indies: X. strumarium is an infrequent, very localised ruderal species found at altitudes of between 0 and 50 m.
Zimbabwe: X. strumarium grows on the banks of watercourses and in cultivated plots on heavy clay soils with high water retention.

General harmfulness
 
Xanthium strumarium is considered a major weed in 28 countries. It is one of the 300 major invasive species in tropical Australia, the Indian Ocean and Oceania.
 
Local harmfulness
 
Algeria : Xanthium strumarium is a minor "weed". Uncommon and not very abundant, it does not generally constitute a nuisance for the crop.
Madagascar: Xanthium strumarium is a recently introduced species and is naturalized in the highlands of Madagascar (above 900 m), yet infrequent but abundant when present and constantly expanding. It is a fast growing species and dispersed by animals and humans: manual weeding may be of limited effectiveness due to the germination which can vary with the rainfall. This is a locally abundant weed in the volcanic area in crop systems of Highlands (Vakinakaratra and Itasy) culture system based on corn and vegetable crops.
New Caledonia: It is common along rivers and roads and is able to invade the neighboring areas of pastures if they are prone to flooding. The soil seed bank is persistent (in Australia a 99% reduction of viable seed bank requires 6 years).
South Africa: It is found in the eastern part of the country, particularly throughout the Kruger National Park along water courses. It is considered a category 1 weed. It contaminates sheep wool and is considered a major weed of maize, very competitive and difficult to manage. It readily invades overgrazed pastures and spreads at the expense of the indigenous species.
Zimbabwe: Xanthium strumarium is an invasive species along watercourses, tracksides and heavy soil plots, especially in the Gonarezhou National Park and Malipati village area where it was first recorded in 1987. The infestation is favoured by the grazing of cattle in the dry season in the cultivated plots. Cattle going to drink at waterholes carry into the plots the fruits which cling to the fleece of the animals. This species can form very high density populations.

Herbarium pictures ReCOLNAT: https://explore.recolnat.org/search/botanique/simplequery=Xanthium%2520strumarium