Galinsoga parviflora

Scientific Name	Galinsoga parviflora Cav.
Common Names	English: Gallant soldier; German: Kleinblütiges Franzosenkraut, Kleinblütiges Knopfkraut; French: galinsoga à petites fleurs, galinsoge parviflore
Description	Seed-producing summer annual weed, 10 to 80 cm (3.93 - 31.49 inch) high and forms a taproot. G. parviflora originates from Peru and spread from France to Germany.

Characteristic Features

Vigorous, up to 3 generations/year.

Young Plant

Spatulate, ovate acuminate, entire, flattened tip, lightly retracted in the middle.

Stems

Usually erect with several three-pronged ramifications, 10 - 80 cm (3.93 - 31.49 inch) tall.

Leaves

Opposite, ovate acuminate, light green, margin finely dentate, lower leaves petiolate, upper leaves nearly sessile.

Flowers

Terminal and axillary cyme.
Flower heads small, numerous, button-like with yellow tube-like disk florets and 5 white lingular margin florets.

Flowering Period

Early summer - autumn.

Fruit

Achenes sparsely appressed, pubescent or glabrous, cylindric to ovoid, with pappus attached. Central achenes ovate, black, covered with short white bristles pappus as long as the fruit, with 8-20 silvery and cut-margined scales. Marginal achenes smooth, 3-blunt-angled, without pappus.

Seeds

Gallant soldier is a shallow germinator (up to 2 cm; 0.78 inch).
Germination occurs from late spring - summer.

Viability of Seeds

>10 years.

Propagation

By seeds. 5,000-10,000 seeds/plant can be dispersed.

Habitat

Arable land, waste places, pavements in towns.

Soil

Nitrogen-rich, warm and loamy or sandy loam soils.

Agricultural Importance

Galinsoga parviflora grows best under moist conditions and therefore can become a serious problem under irrigation or in areas that receive year-round rainfall. It greatly reduces yield due to strong competition for water and nutrients and high abundance often occurs in corn fields. The high reproduction rate and longevity of the seeds causes long-term infestation. Resistant biotypes against herbicides containing Atrazine have been selected by intensive use of triazines.

Useful non-chemical contribution to Integrated Weed Management

Mechanical control methods are very effective against seedlings.