Cosmos sulphureus
(sulphur cosmos)

Preferred Scientific Name

• Cosmos sulphureus Cav.

Preferred Common Name

• sulphur cosmos

Other Scientific Names

• Bidens artemisiifolia (Jacq.) Kuntze
• Bidens artemisiifolia var. sulphurea (Cav.) Kuntze
• Bidens sulphurea (Cav.) Sch.Bip.
• Coreopsis artemisiifolia Jacq.
• Cosmos artemisiifolius (Jacq.) M.R.Almeida
• Cosmos aurantiacus Klatt

International Common Names

• English: cosmos; orange cosmos; yellow cosmos
• Spanish: cempual; chochopali; girasol amarillo; mirasol amarillo; San Miguel; sochipal; suchipate
• French: cosmos soufré
• Chinese: liu huang ju

Local Common Names

• Brazil: beijo de moça; cosmo amarelo; klondike cosmos; picão de flor grande; picão grande
• Costa Rica: cambray
• Cuba: estrella del norte
• Dominican Republic: cyemita
• El Salvador: botón de oro; flor de muerto
• Germany: gelbes Schmuckkorbchen
• Honduras: clavel de muerto
• Japan: kibana-kosumosu
• Mexico: axal-xóchitl; ecaxtli; ehcaxtli; mirasol yellow; shinul; xinula; xochipal; xochipali
• Micronesia, Federated states of: barung; purang; purang palap
• Myanmar: paw-me-tar; sein-chai-kadipa
• Nicaragua: chambray
• Portugal: cosmos-amarelo
• Puerto Rico: panchita
• Russian Federation: kosmos zelyj
• Sweden: gullskara

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

Asteraceae is one of the largest families of flowering plants, containing approximately 1620 genera and more than 23,600 species (Stevens, 2012). In their vegetative state, the members of this family are extremely variable, but they are easily recognized by their flowers (florets) in heads (capitula) surrounded by an involucre of bracts. The small, single-seeded fruit (cypsela), often with a plumose pappus, aids wind dispersal (Stevens, 2012). However, Cosmos belongs to a group of genera that have awns instead of a feathery pappus.

Members of the genus Cosmos originated in the tropical and subtropical regions of the new world, especially in Mexico. About 40 species have their centre of diversity in Mexico. Several species have been introduced around the world, becoming naturalized, and occasionally invasive. These species are closely allied to the beggarticks genera, Coreopsis and Bidens, whose generic boundaries are currently in a state of flux.

C. sulphureus was first described by Cavanilles (1791) from plants cultivated in the Real Jardín Botánico de Madrid from Mexican seed, but the date of its introduction is unknown. It was again described by Jacquin (1793) from plants cultivated in Vienna, Austria (Burkill, 1930). Melchert (1976) described the species as a pantropical weed “doubtlessly native to hot, subtropical regions of central and southern Mexico”.

The genus name Cosmos derives from the Greek word kosmos, literally translated as ‘beauty’ (Smith, 1972) with a “root idea of orderliness; hence an ornament or beautiful thing” (Bailey, 1924). The species name sulphureus is in reference to the orange-yellow colours of the plant’s flower (Smith, 1972).

C. sulphureus is an annual herb 0.3-2 m tall, taprooted. Stems erect, branched, glabrous or sparsely pilose to hispid. Leaves cauline, alternate, deeply lobed; petioles 10-70 mm long; blades 50-250 mm long; ultimate lobes 2-5 mm wide; margins sparsely spinulose-ciliate; apices apiculate. Synflorescences 100-200 mm long, spreading-ascending; bractlets linear-subulate 5-10 mm long with acute apices. Capitula 6-10 mm diameter; involucral bracts erect, oblong-lanceolate, 9-18 mm long with acute to rounded-obtuse apices; ray florets 8(+ in some cultivars) golden yellow to red-orange; laminae obovate, 18-30 mm long with truncate, denticulate apices; disc florets 6-7 mm long. Cypselae light brown, flattened, 1.5-3 mm long, hispidulous, rarely glabrous; pappus absent, or with two or three widely divergent awns, 1-7 mm long (description compiled from Beentje and Hind, 2005; Kiger, 2006; Chen and Hind, 2011; C Puttock, Smithsonian Institution, USA, personal observation).

C. sulphureus is likely to have been introduced to the Caribbean from the mainland at an early date, and herbarium specimen records indicate that the species had escaped cultivation by 1886 in Puerto Rico, 1927 in Haiti, 1945 in Dominican Republic and 1909 in Cuba (US National Herbarium). The species was being cultivated in flower gardens in Bermuda by 1918 (Britton, 1918), in Virgin Islands gardens by 1925 (Britton and Wilson, 1924), and in Dominica by 1985 (Nicolson et al., 1991). It is now a common roadside weed in Puerto Rico (Liogier and Martorell, 2000) and is present in various other parts of the Caribbean including Cuba, Hispaniola, and the US and British Virgin Islands (Acevedo-Rodríguez and Strong, 2012; USDA-ARS, 2016).

In Europe, C. sulphureus was transported to Spain via the galleons and grown in botanical gardens (Sherff, 1932; Staples and Herbst, 2005). According to Burkill (1930), C. sulphureus has remained in cultivation in Europe since it was first described by Cavanilles in 1791 (based on a plant cultivated in the Real Jardin Botanico de Madrid) and is widely available in the horticultural trade. Today, the species is also reported as a roadside and ruderal weed in other parts of Europe, notably in Belgium and Poland (USDA-ARS, 2016).

In Africa, the species was introduced into the high eastern plains of South Africa by way of contaminated horse feed imported from Mexico during the Boer War in 1902. It is now reportedly naturalized in parts of eastern and southern Africa, including not only South Africa but Kenya, Tanzania, Uganda, Malawi and Zimbabwe (USDA-ARS, 2016). In Swaziland it is suspected to be a minor problem species with invasive potential (Swaziland National Trust Commission, 2016).

In Asia-Pacific, the species is thought to have reached the Philippines directly from Mexico via the galleon trade during the second half of the nineteenth century, toward the end of the Spanish colonial period (Merrill, 1904). It has been suggested that C. sulphureus was brought to the Philippines at a later date than its close relative C. caudatus, as C. sulphureus was probably introduced simply for ornamental purposes whereas C. caudatus was used as a vegetable on board the galleons (Merrill, 1923; Burkill, 1930). It was present in Guam by the 1910s, as specimens were collected from the US Guam Experiment Station (US National Herbarium). Similarly, the species has been present in the Marquesas Islands since 1929 (US National Herbarium; Wagner and Lorence, 2016). In the south of mainland Asia, C. sulphureus found its way to India by 1845 (Voigt, 1845) and by 1930 had “run wild” in places “very remote from European stations” (Burkill, 1930).

Soil reaction

• alkaline
• neutral

Soil texture

• light
• medium

Special soil tolerances

• shallow

Vector transmission (biotic)

C. sulphureus seeds are carried externally by animals and dropped locally. The fruits, with a scabrid beak and pappus of two horizontally spreading awns, are adapted for attachment and animal dispersal, but are not adapted for wind dispersal (Jansen, 2005; PlantPono, 2014).

Intentional introduction

C. sulphureus has been introduced widely as an ornamental plant.

• Proved invasive outside its native range
• Has a broad native range
• Abundant in its native range
• Is a habitat generalist
• Tolerates, or benefits from, cultivation, browsing pressure, mutilation, fire etc
• Pioneering in disturbed areas
• Highly mobile locally
• Fast growing
• Has high reproductive potential
• Gregarious
• Has propagules that can remain viable for more than one year
• Has high genetic variability

• Ecosystem change/ habitat alteration
• Reduced native biodiversity
• Threat to/ loss of native species

• Highly likely to be transported internationally accidentally
• Highly likely to be transported internationally deliberately

This species has been used in its native Mexico and Central and South Americas since pre-Colombian times. The flower heads of C. sulphureus, as well as those of other Cosmos species, were used as a popular yellow dye by European settlers for domestic textile production in southern Africa, and today the practice continues as a hobby or for textile crafts, to dye wool bright yellow or orange (Jansen, 2005). C. sulphureus is also commonly cultivated in tropical and temperate regions as an ornamental (P Acevedo-Rodríguez, Smithsonian Institution, USA, personal observation, 2016). In China, the species has been used in traditional medicine for centuries due to its anti-inflammatory, antibacterial and antifungal properties as well as for the treatment of gastric ulcers, liver inflammation and arthritis (Quattrocchi, 2012). In Brazil, it has been recorded as an antimalarial medicinal plant requiring further research (Botsaris, 2007).