Some plants, including dodders, broomrapes, and pinedrops, have no chlorophyll (necessary for photosynthesis) and have become dependent on chlorophyll-bearing plants for their nutrition. They parasitize their host plants via peglike projections called haustoria (singular: haustorium), which develop along the stem in contact with the host.
The haustoria penetrate the outer tissues and establish connections with the xylem and phloem. Some green plants, including Indian warrior and the mistletoes, also form haustoria. These haustoria, however, apparently aid primarily in obtaining water and dissolved minerals from the host plants, since the partially parasitic plants are capable of manufacturing at least some of their own food through photosynthesis.
Other plants lacking chlorophyll (e.g., Indian pipes) are not parasitic at all. Instead, these plants are saprophytic, obtaining all the nutrients they require from organic materials in the soil.
0 comments:
Post a Comment