history of creeping indigo in the usa :
Creeping Indigo had first been imported into the United States in 1925 by the University of Florida in Gainesville, so that its supposed utility as livestock forage and ground cover could be studied. When it was found that rabbits died when they grazed the experimental plots, the project was quickly abandoned! But, they neglected to contain the weed. It has subsequently spread, all over the state.
It has now been confirmed in the following states: FLORIDA, GEORGIA, ALABAMA & HAWAII
In the 1970s, a mysterious and often fatal condition of adult horses and livestock had begun to be recognized called ”Grove Poisoning”. (the notion that toxic chemicals sprayed on trees in local fruit groves was making livestock ill) By the 1980s, however, Dr. Julia Morton had investigated many more incidents and had become convinced that the condition was actually caused by creeping indigo.
By the early 1990s even the doubters had acknowledged the obvious and, although feeding trials have thankfully not been performed in horses to formally establish cause and effect, it is now generally accepted that creeping indigo causes the neurologic syndrome previously known as Grove poisoning.
Over the last 10 years, we have seen similar small outbreaks of the disease in horses and in donkeys in central and north-central parts of the state, especially in areas north of Tampa and around Brooksville. This extension in geographic range of the syndrome appears to correspond to increasing abundance of creeping indigo in the central and north central parts of the state. The origins of this recent wave of invasion by creeping indigo are unclear. It is interesting to hypothesize possible roles for climate change or for introduction or emergence of a new more invasive strain. This is explored more fully below. In any event, creeping indigo has become a very common plant around Alachua and Seminole counties and can be found growing along the edges of many pathways, including many at the University of Florida. Even more threateningly, it has become the dominant herb in some pastures in the Ocala area.
Source of information: UF's Large Animal Veterinary Article titled "Creeping Indigo". Click the link below to read more!
It has now been confirmed in the following states: FLORIDA, GEORGIA, ALABAMA & HAWAII
In the 1970s, a mysterious and often fatal condition of adult horses and livestock had begun to be recognized called ”Grove Poisoning”. (the notion that toxic chemicals sprayed on trees in local fruit groves was making livestock ill) By the 1980s, however, Dr. Julia Morton had investigated many more incidents and had become convinced that the condition was actually caused by creeping indigo.
By the early 1990s even the doubters had acknowledged the obvious and, although feeding trials have thankfully not been performed in horses to formally establish cause and effect, it is now generally accepted that creeping indigo causes the neurologic syndrome previously known as Grove poisoning.
Over the last 10 years, we have seen similar small outbreaks of the disease in horses and in donkeys in central and north-central parts of the state, especially in areas north of Tampa and around Brooksville. This extension in geographic range of the syndrome appears to correspond to increasing abundance of creeping indigo in the central and north central parts of the state. The origins of this recent wave of invasion by creeping indigo are unclear. It is interesting to hypothesize possible roles for climate change or for introduction or emergence of a new more invasive strain. This is explored more fully below. In any event, creeping indigo has become a very common plant around Alachua and Seminole counties and can be found growing along the edges of many pathways, including many at the University of Florida. Even more threateningly, it has become the dominant herb in some pastures in the Ocala area.
Source of information: UF's Large Animal Veterinary Article titled "Creeping Indigo". Click the link below to read more!
Indigo spicata is native to Africa, Madagascar, Southern and Southeast Asia, and has naturalized across tropical regions. It was introduced into Java in 1923 as a nitrogen-fixing cover crop for coffee, tea, rubber, oil palm, and sisal plantations (Morton, 1989). According to Morton (1989) cultivation of the plant spread from Java to the Philippines in 1927, but the species was actually first recorded (as I. hendecaphylla) in the country in 1918 (Merrill, 1919). It was introduced to Hawaii prior to 1949; while the species was not included in Hoakasa and Thistle’s 1954 Noxious plants of the Hawaiian Ranges, by 1965 it was known as a good ground cover although not for fodder, and has now naturalized (Morton, 1989; Wagner et al, 1999).
I. spicata was introduced from southern India to Ceylon and was first grown at Peradeniya in 1921 (Sampson, 1928). The species was then introduced from Ceylon to Gainesville, Florida, United States in 1925 as a cover crop and forage plant, and from there was brought to the Neotropics (Morton, 1989). It was introduced into Jamaica in 1933 to smother weeds in orchards, and taken to Mayaguez, Puerto Rico, in 1937 for planting as green manure, a soil binder, and forage for cattle, but soon became considered a weed after it was found to have toxic effects on cattle and other grazing animals (Morton, 1989). In 1979, it was collected on the other side of Puerto Rico (Carite) showing a rapid colonization of the island. Nowadays, it is very common and naturalized in Puerto Rico (US National Herbarium). It was present in Guadeloupe by 1935 (US National Herbarium). The first record of the species in Dominica (as Indigofera hartwegii) is from 1989 (Nicholson, 1991), however, a reexamination of this collection showed it to refer to I. hendecaphylla. Despite its invasiveness and reported toxicity, I. spicata continues to be commonly used as a cover crop around the world today.
(reference: http://www.cabi.org/isc/datasheet/79262)
See more information regarding how it got to the United States, see: http://largeanimal.vethospitals.ufl.edu/2014/11/03/creeping-indigo-toxicity/
I. spicata was introduced from southern India to Ceylon and was first grown at Peradeniya in 1921 (Sampson, 1928). The species was then introduced from Ceylon to Gainesville, Florida, United States in 1925 as a cover crop and forage plant, and from there was brought to the Neotropics (Morton, 1989). It was introduced into Jamaica in 1933 to smother weeds in orchards, and taken to Mayaguez, Puerto Rico, in 1937 for planting as green manure, a soil binder, and forage for cattle, but soon became considered a weed after it was found to have toxic effects on cattle and other grazing animals (Morton, 1989). In 1979, it was collected on the other side of Puerto Rico (Carite) showing a rapid colonization of the island. Nowadays, it is very common and naturalized in Puerto Rico (US National Herbarium). It was present in Guadeloupe by 1935 (US National Herbarium). The first record of the species in Dominica (as Indigofera hartwegii) is from 1989 (Nicholson, 1991), however, a reexamination of this collection showed it to refer to I. hendecaphylla. Despite its invasiveness and reported toxicity, I. spicata continues to be commonly used as a cover crop around the world today.
(reference: http://www.cabi.org/isc/datasheet/79262)
See more information regarding how it got to the United States, see: http://largeanimal.vethospitals.ufl.edu/2014/11/03/creeping-indigo-toxicity/
