Croton argenteus
(silver July croton)

Preferred Scientific Name

• Croton argenteus L.

Preferred Common Name

• silver July croton

Other Scientific Names

• Cicca argentea (L.) Kuntze
• Cicca montevidensis (Klotzsch ex Baill.) Kuntze
• Cieca argentea (L.) Kuntze
• Cieca montevidensis (Klotzsch ex Baill.) Kuntze
• Croton atwoodianus F.Seym.
• Croton integer (Chodat) Radcl.-Sm. and Govaerts
• Heterochlamys quinquenervia Turcz.
• Heterochlamys quinquinervis Turcz.
• Julocroton argenteus (L.) Didr.
• Julocroton argenteus var. managuensis Ram.Goyena
• Julocroton camporum Chodat and Hassl.
• Julocroton elaeagnoides S.Moore
• Julocroton integer Chodat
• Julocroton integer f. parvifolia Chodat and Hassl.
• Julocroton linearifolius (Chodat and Hassl.) Croizat
• Julocroton montevidensis Klotzsch ex Baill.
• Julocroton montevidensis var. elata Chodat and Hassl.
• Julocroton montevidensis var. glabra Herter
• Julocroton montevidensis var. guatemalensis Müll.Arg.
• Julocroton montevidensis var. lanceolatus Müll.Arg.
• Julocroton montevidensis var. linearifolius Chodat and Hassl.
• Julocroton montevidensis var. pilosus Müll.Arg
• Julocroton montevidensis var. virgatus Chodat and Hassl.
• Julocroton pilosus (Müll.Arg.) Herter
• Julocroton quinquenervius Baill.

International Common Names

• Spanish: croto; croton
• Portuguese: velame-da-lagoa

Local Common Names

• Cuba: yulocroton

• Domain: Eukaryota
•     Kingdom: Plantae
•         Phylum: Spermatophyta
•             Subphylum: Angiospermae
•                 Class: Dicotyledonae
•                     Order: Euphorbiales
•                         Family: Euphorbiaceae
•                             Genus: Croton
•                                 Species: Croton argenteus

The family Euphorbiaceae includes around 218 genera and 6,745 species with Pantropical distribution. Euphorbiaceae species can be recognized by the following traits: the leaves on one branch are often variable in size and/or shape, the secondary veins are often palmate, the margins are toothed, and there are sometimes glands of various kinds. Species are monoecious or dioecious, the flowers are small, the perianth is usually inconspicuous, there are usually three carpels with prominent stigmas, and the fruits have a distinctive and persistent columella, large and often carunculate seeds and explosive dehiscence. Euphorbiaceae species are quite often poisonous (Stevens, 2012). With about 1300 species, Croton is the second largest genus within the family Euphorbiaceae. Croton species are trees, shrubs, and herbs distributed in warm-temperate regions. South America, the West Indies and Mexico are important centres of species diversity for this genus (Webster, 1993; Burger and Huft, 1995).

The following description comes from Burger and Huft (1995):

Annual herbs 0.2-1 m tall, bisexual, leafy stems 0.8-7.5 mm thick, stellate-pubescent with appressed hairs 0.3-0.5 mm diameter or with long rays to 0.9 mm; stipules 4-11 mm long, linear-subulate, simple or divided distally, with hairs to 1.4 mm long. Leaves often closely congested beneath the inflorescences, petioles 3-105 mm long, 0.7-2 mm thick, appressed stellate-pubescent, glands absent at apex; leaf blades 1.8-10(-15) cm long, 1.2-6(-8) cm wide, ovate to ovate-oblong, apex bluntly obtuse to rounded, margin minutely or obscurely denticulate, base obtuse or cuneate to subtruncate, drying chartaceous and pale grayish green beneath, stellate-pubescent with appressed hairs 0.1-0.4 mm diameter, venation palmate with usually 5 major veins from the base. Inflorescences terminal, bisexual, 1-4 cm long, often subtended by small (15 ×12 mm) leaves, congested and resembling a capitulum, bracteoles approximately 3 mm long, subtending solitary flowers, female flowers proximal, pedicels to 5 mm long in fruit, male flowers with pedicels 2 mm long. Male flowers with calyx 1.5-2 mm long, sepal lobes approximately 1 mm long, petals 2-3 mm long, 0.3-0.4 mm wide, glabrous except on the margin; stamens 11, anthers 0.6-0.8 mm long. Female flowers with 5 unequal sepals, 6-8 mm long in fruit, petals absent, disk with 5 unequal lobes, styles distally 4 times bifid. Fruits 5 mm long, borne on pedicels 3-5 mm long, sepals 6-8 mm long and 3.5-6 mm wide, columella 3-4.5 mm long; seeds 3.2-3.8 mm long, 2.4-3 mm wide, 2.2 mm thick, rounded-oblong, caruncle approximately 1.8 mm wide).

Soil drainage

• seasonally waterlogged

Soil reaction

• acid
• neutral

Soil texture

• light
• medium

C. argenteus spreads by seeds. Seeds are often dispersed as a contaminant in dried and wet mud (Standley and Steyermark, 1946).

Currently, C. argenteus is listed as invasive only in Cuba (Oviedo Prieto et al., 2012). However, within and outside its native distribution range, this species grows as a weed impacting agriculture (i.e., rice and sugarcane plantations), pastures, and wet and dry thickets (Standley and Steyermark, 1946; Burger and Huft, 1995). In Cuba, this species occurs extensively across the island principally in the western region, where it is a common weed in ruderal areas, pastures, agricultural lands, and along roadsides (Morón Rodríguez et al., 2006).

• 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
• Fast growing

• Negatively impacts agriculture
• Reduced native biodiversity

• Competition - monopolizing resources
• Competition - smothering
• Rapid growth

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

C. argenteus is used in traditional medicine to treat health problems, such as diarrhoea, wounds, gastroduodenal ulcers, inflammations, pain, insect bites, and viral infections (Morón Rodríguez et al., 2006).