,
Cape Town.
Natural distribution The species is rare and declining in its native
South Africa. It is naturally restricted to lowland, winter-rainfall areas in
Cape Town and also up to
Malmesbury, just to the north. It is therefore entirely
endemic to the
Western Cape Province. It is still declining, because of competition from invasive alien plants, but mainly due to the destruction of many of the remaining parts of its habitat.
Seed dispersal Reaching approximately 10 cm (4") when in flower, this species spreads through two main methods, both of which lend to its common name. The first of these two methods is simply dropping the seeds of the plant up to 20 cm (8") away from the base of the original plant.
Control methods The reason this weed is so hard to control is its ability to reproduce in such great numbers, and the damage it does when removed. Seeds of the yellow soldier are next to impossible to see in the soil or on the shoes of removalists, and germinate easily, negating the effect of the removal program. Removal by hand is labour-intensive, with only 4m² (42 square feet) being removed in a 6-hour period (Weed Management Guide). The ability to grow back from its root system means that the entire plant must be removed from the ground, allowing other weeds to germinate. Controlled burning is also ineffective; it actually increases the number of yellow soldiers in the area. In studies conducted, it has been found that fire increases the germination rate of yellow soldier seeds, and does not kill off any of the plants, due to its ability to grow back from its root system. The yellow soldier also germinates faster after a fire than native plants, allowing it complete dominance over a larger area than before the fire. The only effective way to remove yellow soldier is through spot-spraying of
herbicides. Once again, however, the ability to quickly germinate from seed means that multiple courses of spraying must be done in order to eliminate yellow soldier, and allow native species the chance to reclaim the soil. The herbicide developed to kill only yellow soldier is expensive and therefore can usually only be done through government funding. This prevents most environment and bush care groups from eliminating the species, and thus allowing it the chance to spread further. ==References==