Taxonomic name: Solanum mauritianum (Scopoli, 1788)
Synonyms: Solanum auriculatum Aiton 1789, Solanum carterianum Rock 1913, Solanum tabaccifolium Vell. 1829, Solanum verbascifolium L. forma typicum Hassl. 1918, Solanum verbascifolium L. ssp. auriculatum (Aiton) Hassl. 1918, Solanum verbascifolium L. var. auriculatum (Aiton) Kuntze 1891
Common names: bois de tabac marron (French-Reunion (La Réunion)), bringellier marron (French-Reunion (La Réunion)), bugweed (English), flannel weed (English-New Zealand), groot bitterappel (Afrikaans), igayintombi (Zulu), isigwayana (Zulu), kerosene plant (English-New Zealand), luisboom (Afrikaans), morelle de Maurice (French), pua nana honua (Hawaii), pula (Tonga), rau 'ava'ava (Cook Islands), tabac marron (French-Reunion (La Réunion)), tobacco weed (English-New Zealand), tree tobacco (English), umbanga banga (Zulu), wild tobacco (English), woolly nightshade (English-New Zealand)
Organism type: tree, shrub
Solanum mauritianum is a widespread invasive weed belonging to the nightshade family. It has the ability to crowd out native plants if growing densely, but, if occurring sparsely, it may act as a nursery crop. All parts of Solanum mauritianum plant are poisonous to humans, especially the berries. This plant is dispersed by birds, with the fruit being especially favoured by some species. Biological control of this species has been undertaken in South Africa.
"Shrubs or small trees 2-10m tall, branched above to form a rounded canopy, unarmed, all parts densely pubescent with
sessile to long-stalked stellate hairs, loose and floccose on young growth. Leaves paler on lower surface, simple, alternate, elliptic, up to0 cm long and 12cm wide on young vigorous growth, usually ca 8 cm long and ca 7cm wide, on mature stems. When crushed they give off a smell of diesel fuel. Margins entire, apex acuminate, base cuneate, often oblique, petioles 3-9cm long, each with 1-2 smaller auriculate leaves in axils, these sessile, rounded, sometime absent from weak or distal shoots. Flowers perfect, actinomorphic, numerous in branched corymbs, peduncles up to 15cm long to first fork, pedicels 2-3mm long; calyx tube short, 2-3mm long, the lobes narrowly triangular, 2-3mm long; corolla lilac blue with a pale star-shaped area at base, stellate, 1.5-2.5cm in diameter; stamens 5, inserted low on corolla tube; filaments ca 1mm long; anthers oblong, 2-3.5mm long, opening by terminal pores; ovary densely pubescent; style pubescent in lower part, 5-7mm long; stigma green, terminal. Berries green, ripening to dull yellow, succulent, globose, 1-1.5cm in diameter, pubescent at least in early stages. Seeds numerous, flattened, 1.5-2mm long, testa minutely reticulate. Self-compatible ."" (Wagner et al., 1999, in PIER, 2002)"
Solanum densevestitum, Solanum stelligerum
agricultural areas, coastland, natural forests, planted forests, riparian zones, ruderal/disturbed, urban areas
In Hawai‘i, naturalized on slopes and ridges in disturbed wet forest (Wagner et. al. 1999 in PIER, 2002). A coloniser of disturbed sites (KZN Wildlife). Tolerates various soil types and is shade-tolerant to a certain degree (Haley, 1997). In South Africa, the plant invades riparian zones, forestry plantations, natural forest, agricultural lands, urban open space and any other disturbed areas (e.g. along roadsides, powerlines etc.), particularly in the eastern, higher rainfall regions of the country (Henderson, 2001).
Can invade urban areas, native forest margins and pastoral land. May form dense stands that inhibit the growth of other species through overcrowding and shading (Haley, 1997). Can retard the growth of young pine trees (Pinus spp.) (Wildy, 2002). All parts of the plant are poisonous to humans, especially the green berries (ESC, 2003). These berries also provide winter food for the Mediterranean and KwaZulu-Natal fruit flies, which are horticultural pests. The fine hairs on the leaves can be an irritant, especially when they are dislodged during removal operations (Wildy, 2002).
Can be used as a nursery crop in countries where it is less invasive than elsewhere (e.g. Australia). This is because it can provide a protective environment for native vegetation to germinate and grow underneath. This is dependent on the situation though, as it will not be effective if S. mauritianum is so thick that it shades out plants growing beneath it. The fruit may be a valuable food source for native bird species, although these tend to facilitate long-distance dispersal and further invasion (CGC, 2003; T. Olckers, pers. comm.).
Native range: Northern Argentina, Uruguay, Paraguay and Southern Brazil.
Known introduced range: Cook Islands, Fiji, French Polynesia (debatable), Hawai‘i, New Caledonia, Norfolk Island, Solomon Islands, Tonga, La Réunion Island, Mauritius, Madagascar, Australia, India and several southern African countries.
Invasive in:New Zealand, South Africa, Australia.
Introduction pathways to new locations
Agriculture: Invaded rangelands (T. Olckers, pers. comm.)
For ornamental purposes: Introduced to New Zealand as a garden plant. (Mather, 1998). Introduced for flowers and to attract fruit-feeding birds (T. Olckers, pers. comm.)
Forestry: Invaded plantations (T. Olckers, pers. comm.)
Local dispersal methods
Agriculture (local): Local source of invasion (T. Olckers, pers. comm.)
Consumption/excretion: Seed spread by birds and other animals. (Eurobodalla Shire Council, 2003). Dispersal is mainly through birds, which eat the fruit and deposit the seeds long distances from the host plant (Haley, 1997).
Forestry (local): Local source of invasion (T. Olckers, pers. comm.)
Garden escape/garden waste: Spread by seed in dumped garden waste. (Eurobodalla Shire Council, 2003)
Chemical: Easily killed with herbicides. In South Africa, several chemicals (e.g. glyphosate, triclopyr, imazapyr) are registered as foliar, basal stem or cut stump applications. Manual control involves ring-barking trees or removing seedlings by hand (Wildy, 2002).
Biological: Biological control has been instituted in South Africa, with the release of a sap-sucking lace bug (Gargaphia decoris) in 1999 (Olckers, 1999, 2000). However, this insect has proved ineffective to date. Permission for the release of the flowerbud weevil (Anthonomus santacruzi) that prevents fruiting is currently being sought in South Africa (T. Olckers, pers. comm.).
Seed. Some 20-80 berries are borne on each inflorescence, each of which contains about 150 seeds (T. Olckers, pers. comm.).
Flowers and fruits all year round (Wildy, 2002). Germination of seeds stored in soil is stimulated by fire (ESC, 2003). Seedlings that become established in summer can flower by autumn. Plants can grow to a height of several metres within 2-3 years. Mature plants begin to die after 15 years (Haley, 1997).
Reviewed by: Dr. Terry Olckers, ARC - Plant Protection Research Institute, South Africa.
Compiled by: IUCN/SSC Invasive Species Specialist Group (ISSG)
Last Modified: Wednesday, 22 February 2006