Rhododendron ponticum can grow up to ten meters in height and can have a substantial amount of growth laterally. The lateral growth essentially allows the plant to 'jump' over obstacles where the roots cannot grow. For example, the roots will become established on one side of a stream, lateral growth will take place over the stream, and roots will then establish on the other side.
     These adaptations increase the plants surface area enabling it to reach more sunlight and simultaneously blocking sunlight from other organisms.

©Franz Xaver 2008

    Forming a mutualistic relationship with mycorrhiza is a great adaptation. The mycorrhiza is increasing the surface area of Rhododendron ponticum's roots; therefore, allowing it to gain more nutrients. This gives Rhododendron ponticum a competitive edge over plants without mycorrhiza in its roots.

     Potentially toxic chemicals are present in substantial amounts in Rhododendron ponticum. Due to these toxic chemicals, the plant is unpalatable to predators such as herbivores, omnivores, and some insects. To learn more about the toxins present in Rhododendron ponticum, click here.

    When Rhododendron ponticum seeds are dispersed into an area that is not suitable for growth, they can be dormant for several years. If the conditions become favorable for growth within those several years, the viable seed can become a plant.

    When Rhododendron ponticum is mature, the leaves become physically tough. This is an added defense against herbivores and other organisms that may try to feed on the leaves of Rhododendron ponticum. They also have a waxy coating to prevent desertification.

©Design for unity

Leaf buds                                                                                                        
    When leaf buds are forming, small invertebrates may try to feed on them. To deter this, there is a sticky exudate which will trap any of these invertebrates.

     Rhododendron ponticum is also a successful invasive plant for other reasons. It can withstand somewhat harsh habitats and it is a good competitor. Rhododendron ponticum can form very thick bushes, depleting sunlight and water from other organisms around them.
    Much of Europe is experiencing a problem with the invasion of Rhododendron ponticum. Rhododendron ponticum is typically the better competitor in comparison to native species in the same ecological niche. To learn more about the invasion, click here.

©National Trust Images/David Levenson

Andromedo-toxin in Rhododendron ponticum