A network that helps people worldwide obtain rapid advice and information on crop protection, including the identification and management of plant pests.
PestNet is a network that helps people worldwide obtain rapid advice and information on crop protection, including the identification and management of plant pests. It started in 1999. Anyone with an interest in plant protection is welcome to join. PestNet is free and is moderated, ensuring that messages are confined to plant protection.
November 2002. A weed from Palau that was allowed to develop flowers so that it could be identified. It is about 0.5 m tall. It was thought to be velvetleaf, Abutilon theophrasti. Each time the plant has appeared it has been associated with chicken manure. It seems that the seeds survive passage through the digestive system of chickens. The seeds enter Palau in chicken feed imported from California. Velvetleaf is not recorded as being present in the country. It is reported to be a serious weed of many crops in the USA.
In Israel, it arrived most probably with cheap freshwater fish food from the USA. It is extremely common everywhere there are fishponds. From those places it reached cattle farms. Viable seeds are present in cow manure. In cotton fields fertilized with cow manure velvetleaf may reach a height of 2.5 m under ideal irrigation conditions. In the same way fields became infected with Anoda cristata another serious weed species in the Malvaceae.
Animal feed importers need to be made aware of the need to import only ‘clean’ products. Unprocessed grain imports are likely to have more unwanted weed contaminants than processed feed pellets. The Pacific needs to put in place mechanisms to safeguard against such unwanted introductions.
It is thought that the weed occurs in Papua New Guinea, although no surveys have yet confirmed its presence. Certainly, A grandiflorum does occur there as well as in some other Pacific islands. According to the CABI Crop Protection Compendium, A theophrasti occurs in China, the USA, South Eastern Europe, India and Australia.
Certainly, this is a weed that threatens Pacific Island countries. There is a need to assess the pathways of introduction and make necessary regulatory steps to prevent further introductions. The species is reported to have a seed viability of 45 years and that is not good news if there are suitable habitats where this plant can thrive in the region.
Previously, flowers of this weed were found in a supermarket in Pohnpei, Federated States of Micronesia (photo, lower right). Large amounts of dried flowers are displayed for sale and the manager has been asked to remove the product for sale until a risk assessment has been made. The exporting company has been contacted. In the Iconographia Cormophytorum Sinicorum, there are nine species of Abutilon in China. They are A. crispum, A. roseum, A. sinense, A. gebauerianum, A. striatum, A. paniculatum, A. hirtum, A. theophrasti, A. indicum. But this book only provides pictures of two species: A. theophrasti and A. indicum. The dried flowers were similar to A. theophrasti. This plant is distrubuted all over the world for its medicinal properties.
The stem is used in the manufacture of textiles. Oil from the seed is used to make paint and soap. Its seed can be used as a medicine, instead of Malva crispa, as a diuretic. The root and the whole plant can be used for other medicines – it can relieve internal heat or fever as well as rheumatic pains.
In The Grower’s Weed Identification Handbook” from the University of California is says:
The fruit is disklike, 4/5 to 1 1/5 inches (20 to 30 mm) broad and 3/4 inch (19 mm) high. It consists of a circle of 9 to 15 individual seed cases, each with a beak tapering to a point. Each seed case eventually splits to release the seed.
… and the seeds …
The seed are kidney shaped or unevenly heart shaped and dark grayish brown with very small, scattered, star-shaped (stellate) hairs on the surface. Buried in the soil, they may remain viable for 50 years or more.
Later, in August 2003, a member from China provided more information about the weed. He wrote: “these days I know that Abutilon theophrasti is a weed in China. It seems that it is very common in our country. Other popular medicinal plants are Morinda citrifolia and Calophyllum inophyllum.
There are five species of plants in the genus Morinda in China. They are M. citrifolia, M. cochinchinensis, M. officinalis, M. parvifolia and M. umbellata. Every one of them can be used as medicine, but M officinalis seems the most important plant in this genus because there are many articles about it in China. It seems that it has the function of antidepressant and some other function.
At the same time, there are three species plants in the genus Calophyllum in China.They are C. inophyllum, C. thorelii and C. membranaceum. All can be used as medicine. However, it seems that less research has been done on these species.