The Relationship Between a Mistletoe & a Poplar Tree | Home Guides | SF Gate
Mistletoe is a common plant throughout North Carolina that can be found growing on the branches of deciduous trees. This same mistletoe is. Mistletoe is a fungus-parasite. Spruce trees (like many others) are "Mistletoe Flop -houses. Q: What is symbiosis? A: It's a close long-term relationship between different species in a community. Q: What is parasitism? A: When 1.
Trojan Horse Mechanism Mistletoe has a botanical Trojan horse relationship with its host tree. As a result, the tree continues to deliver water and nitrogen through the branch, which the mistletoe pilfers. Mistletoe also releases growth-regulator chemicals that imitate those of young tree tissue. The tree responds by sending additional nutrients to nurture the needs of its perceived new growth.
Damage As mistletoe parasitizes its host tree, it causes the greatest damage during periods of drought. Older and weak trees may suffer stunted growth, reduced vigor and branch dieback.
When mistletoe is producing flowers and berries during autumn and winter, it pulls even more nutrients from trees.
What is the relationship between spruce and mistletoe
In severe mistletoe infestations, particularly during dry periods, trees may die. Management The only permanent control for mistletoe is to remove it from its host tree, which is easier said than done. Because the haustoria grow up to 12 inches inside the branches, they must be removed also or the shrub will re-sprout. Mistletoe in winter All mistletoe species are hemiparasitesbecause they do perform at least a little photosynthesis for at least a short period of their life cycle.
However, in some species its contribution is very nearly zero. For example, some species, such as Viscum minimumthat parasitize succulentscommonly species of Cactaceae or Euphorbiaceae, grow largely within the host plant, with hardly more than the flower and fruit emerging. Once they have germinated and attached to the circulatory system of the host, their photosynthesis reduces so far that it becomes insignificant.
Some species, such as Viscum capenseare adapted to semi-arid conditions and their leaves are vestigial scales, hardly visible without detailed morphological investigation. Therefore their photosynthesis and transpiration only take place in their stems, limiting their demands on the host's supply of water, but also limiting their intake of carbon dioxide for photosynthesis. Accordingly their contribution to the host's metabolic balance becomes trivial and the idle parasite may become quite yellow as it grows, having practically given up photosynthesis.
Not only do they photosynthesize actively, but a heavy infestation of mistletoe plants may take over whole host tree branches, sometimes killing practically the entire crown and replacing it with their own growth.
In such a tree the host is relegated purely to the supply of water and mineral nutrients and the physical support of the trunk. Such a tree may survive as a Viscum community for years; it resembles a totally unknown species unless one examines it closely, because its foliage does not look like that of any tree. An example of a species that behaves in this manner is Viscum continuum.
It commonly has two or even four embryos, each producing its hypocotylthat grows towards the bark of the host under the influence of light and gravity, and potentially each forming a mistletoe plant in a clump. Possibly as an adaptation to assist in guiding the process of growing away from the light, the adhesive on the seed tends to darken the bark. On having made contact with the bark, the hypocotyl, with only a rudimentary scrap of root tissue at its tip penetrates it, a process that may take a year or more.
The Relationship Between a Mistletoe & a Poplar Tree
In the meantime the plant is dependent on its own photosynthesis. Only after it reaches the host's conductive tissue can it begin to rely on the host for its needs. Later it forms a haustorium that penetrates the host tissue and takes water and nutrients from the host plant.