Galinsoga quadriradiata
(shaggy soldier)

Preferred Common Name

• shaggy soldier

Other Scientific Names

• Adventina ciliata Raf.
• Ageratum perplexans M.F. Johnson
• Baziasa urticifolia (Kunth) Steud
• Galinsoga aristulata E. P. Bicknell
• Galinsoga bicolorata St. John & D. White
• Galinsoga brachystephana Regel
• Galinsoga caracasana (DC.) Sch.Bip.
• Galinsoga ciliata (Raf.) S.F. Blake
• Galinsoga eligulata Cuatrec.
• Galinsoga hispida Benth.
• Galinsoga humboldtii Hieron.
• Galinsoga urticifolia (Kunth) Benth.
• Jaegeria urticifolia (Kunth) Spreng.
• Sabazia urticifolia (Kunth) DC.
• Stemmatella urticifolia (Kunth) O.Hoffm. ex Hieron.
• Vargasia caracasana DC.
• Wilborgia urticifolia Kunth

International Common Names

• English: hairy galinsoga
• Spanish: aceitilla; cominillo; hoja nueva; manzanilla
• French: galinsoga cilié
• Chinese: cu mao niu xi ju

Local Common Names

• Brazil: fazendeiro; picão-branco
• Denmark: almindelig timian; malbladet timian
• Ecuador: hierba de cuy
• Estonia: karvane võõrkakar
• Finland: kangasajuruoho; kirjopikarililja
• Germany: Behaartes Franzosenkraut
• Guatemala: San Nicolas
• Honduras: cominillo rosado
• Hungary: borzas gombvirág
• Lithuania: blakstienotoji galinsoga
• Mexico: aceitilla chica; chía real; estrellita
• Netherlands: harig knopkruid
• Norway: kryddertimian; rutelilje; smaltimian
• Sweden: backtimjan; kryddtimjan; kungsängslilja
• USA: quickweed

• Domain: Eukaryota
•     Kingdom: Plantae
•         Phylum: Spermatophyta
•             Subphylum: Angiospermae
•                 Class: Dicotyledonae
•                     Order: Asterales
•                         Family: Asteraceae
•                             Genus: Galinsoga
•                                 Species: Galinsoga quadriradiata

The family Asteraceae is one of the most diverse groups among flowering plants, including 1620 genera and about 23,600 species (Stevens, 2012). Species in the Asteraceae are very variable vegetatively, but may be recognized by their “capitulate” and involucrate inflorescences in which numerous small flowers open first on the outside and are infrequently subtended by bracts. The anthers in this family are usually fused and form a tube through which the style extends before the two stigmatic lobes separate and become recurved. The rather small, single-seeded fruits usually have a plumose “pappus” and are frequently dispersed by wind (Stevens, 2012).

The genus Galinsoga includes approximately 14 species native to the New World (Pruski, 2014). This genus is closely related to genera Sabazia (Mexico and South America) and Alloispermum (South America), and some botanists believe that all these genera might best be treated as a single large Galinsoga genus (Canne, 1977, 1978). G. quadriradiata (native to Mexico) is a common weed in most temperate and subtropical regions of the world and is morphologically the most variable species within this genus (Canne, 1977).

G. quadriradiata is an annual herb, 8–62 cm tall. Leaf blades 20–60 × 15–45 mm. Peduncles 5–20 mm. Involucres hemispheric to campanulate, 3–6 mm diameter. Phyllaries deciduous, outer paleae deciduous, broadly elliptic to obovate, 2–3 mm; inner deciduous, linear to lanceolate, 2–3 mm, entire or 2- or 3-lobed, lobes to 1/3 total lengths, blunt. Ray florets (4 or) 5 (to 8); corollas usually white, sometimes pink, laminae 0.9–2.5 × 0.9–2 mm. Disk florets 15–35. Ray achenes 1.5–2 mm; pappus of 6–15 fimbriate scales 0.5–1 mm; pappus absent or of usually 14–20, rarely 1–5, white, lanceolate to oblanceolate, fimbriate, sometimes aristate, scales 0.2–1.7 mm (Flora of North America Editorial Committee, 2014).

G. quadriradiata was reported in North America in the 1830s. It was recorded as “naturalized” in 1836 in Philadelphia, where it was growing in the Bartram Botanical Garden (Kagima 2000; Madsen and Wersal, 2014). In Europe, G. quadriradiata was first recorded at the end of the nineteenth century, and it is now established in many European countries (Kabuce and Priede, 2010). In Germany, G. quadriradiata was first found in Hamburg in 1892, and it was first reported in 1925 in the Netherlands (Reinhardt et al., 2003). In the Baltic countries, G. quadriradiata was first found in Estonia in 1921 and in Lithuania in 1924 (Kuusk et al., 2003). In the Nordic countries the first reports of G. quadriradiata are from Norway in 1900, Sweden in 1926, Denmark in 1927, and Finland in 1928 (Kabuce and Priede, 2010). In Russia, G. quadriradiata was found in 1842 as escaped from the St-Petersburg Botanical Garden and occasionally it has been found in the European part of Russia since the 1920s.

After 1945, this species has expanded to Ukraine, Belarus and to the north-western and central districts of Russia where it was registered in the 1970s. In 1991 it was recorded in Siberia (Schultz, 1984; Kabuce and Priede, 2010). For most of the European countries where G. quadriradiata is now naturalized, it has been hypothesized that this species was introduced unintentionally, probably transported as a contaminant in imported seeds and seedlings of ornamental plants, soil, grains, crop seeds, or other agricultural products (Reinhardt et al., 2003; Kabuce and Priede, 2010). In the Caribbean, G. quadriradiata was first collected in Jamaica in 1903, in Bermuda in 1908, and in Puerto Rico in 1915 (US National Herbarium).

Soil reaction

• alkaline
• neutral

Soil texture

• heavy
• medium

G. quadriradiata spreads by seeds. Seeds are enclosed in an achene and are small (1.5 mm long) and adapted to wind-dispersal. Seeds may also be secondarily dispersed as a contaminant in imported seeds and seedlings of ornamental plants, soil, grains, crop seeds, agricultural machinery or adhered to cattle, animal fur and human clothes (Reinhardt et al., 2003; Kabuce and Priede, 2010). Seeds are viable for only a few years under field conditions (Huffman, 2004).

G. quadriradiata is one of the most common weeds in North America and Europe where it causes important economic damage to agriculture and the nursery trade. The species is a strong competitor in weedy plant communities and it is a permanent problem for many farmers including commercial greenhouses. G. quadriradiata may reduce yields by up to 10-50% in fields planted with vegetables and crops (Kabuce and Priede, 2010; Madsen and Wersal, 2014). It has the potential to outcompete other plants in taking up nutrients and it may also shade out cultivated and native plants (Reinhardt et al., 2003).

• Proved invasive outside its native range
• Abundant in its native range
• Highly adaptable to different environments
• Is a habitat generalist
• Tolerates, or benefits from, cultivation, browsing pressure, mutilation, fire etc
• Pioneering in disturbed areas
• Highly mobile locally
• Benefits from human association (i.e. it is a human commensal)
• Fast growing
• Has high reproductive potential

• Ecosystem change/ habitat alteration
• Modification of successional patterns
• Negatively impacts agriculture
• Reduced amenity values
• Reduced native biodiversity
• Threat to/ loss of native species

• Competition - monopolizing resources
• Rapid growth

• Highly likely to be transported internationally accidentally
• Difficult to identify/detect as a commodity contaminant
• Difficult to identify/detect in the field

In Africa and Southeast Asia, the young stems and leaves of G. quadriradiata are cooked and eaten as a vegetable. In America, dried leaves are used as an essential flavouring for certain dishes (Kagima 2000; Kabuce and Priede, 2010). In Mexico, it is used as animal forage (Vibrans, 2009).