Crotalaria cobalticola is an erect annual plant with a slender stem that is much-branched from the base; it can grow 30 - 60cm tall[
The plant is found especially on soils rich in cobalt and copper. It is seen as an indicator of potential deposits of these metals in the soil[
Crotalaria cobalticola has a very restricted natural range and is strictly endemic to copper-rich soil (i.e., it is an absolute metallophyte). However, even if its natural habitat is being destroyed by mining activities, this species is able to colonize secondary metalliferous habitats, such as substrate disturbed and reworked by the mining industry (often mine debris). The plant is classified as 'Least Concern' in the IUCN Red List of Threatened Species(2013)[
No specific mention of toxicity has been seen for this species, but many members of this genus are known to contain pyrrolizidine alkaloids, the most potent of which in this genus are monocrotaline, retrorsine and retronecine[
]. These alkaloids have a cumulative effect upon the body and, unless concentrations in a plant are high, occasional consumption is generally completely safe. Pyrrolizidine alkaloids are derived from amino acids including ornithine. Many of these alkaloids have pronounced hepatic toxicity, but the lungs and other organs may be affected as well. Mutagenic and carcinogenic activities of pyrrolizidine alkaloids have also been reported[
Tropical Africa - southern DR Congo
In grassy places with Eragrostis boehmii on highly metalliferous soils, often in a disturbed zone at the base of hills; contents of cobalt in the soil 400 - 1,900 ppm[
|Conservation Status||Least Concern
|Other Uses Rating||
Annual and short-lived perennial plants in this genus generally gow best in a sunny position, succeeding in most dry to moist, well-drained soils[
We have no specific report for this species, but most species in this genus have a symbiotic relationship with certain soil bacteria; these bacteria form nodules on the roots and fix atmospheric nitrogen. Some of this nitrogen is utilized by the growing plant but some can also be used by other plants growing nearby[
The plant is restricted to soils rich in copper and cobalt. As such, it is seen as an indicator of copper and cobalt deposits. In addition, because it grows vigorously and also concentrates these metals in its above ground parts, it is an effective hyperaccumulator and can be used in phytoremediation projects[
Ashes of the plant (2% of dry weight) growing in a soil containing 1,900 ppm cobalt were found to contain 17,700 ppm cobalt and 530 ppm copper[
]. The species seems not to be restricted to metalliferous soils but is tolerant to them[
Seed - sow in situ. Pre-soaking the seed for 12 hours in warm water can help to reduce germination time.
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