However, radical bud for vegetative reproduction is found in sweet potato ( Ipomoea batatas ), wood apple ( Aegle marmelos ), pointed gourd (Trichosanthes dioica), Indian redwood tree ( Dalbergia sissoo ), etc. Root does not bear buds, leaves, flower, fruits, etc.Root is not differentiated into nodes and internodes.In screwpine (Pandanus racemosus), there is multiple root caps. But in aquatic plants, there are root pockets for balancing. Root is protected at its tip by a protective structure called root cap.Roots are positively geotropic, positively hydrotropic and negatively phototropic.It bears lateral roots of several orders that are refered to as secondary and tertiary roots. It is direct elongation of the radicle, it develops and forms primary root. Some examples are sundew ( Drosera), venus fly-trap (Dionea), bladderwort ( Utricularia), butterwort ( Pinguicula), Aldrovanda, Nepenthes (The Asiatic pitcher plant) Sarracenia (The north-American pitcher plant). They are green in colour and prepare their own carbonaceous food, while they partially depend on insects and other animals for nitrogenous food. They often grow in nitrogen deficient soils. Carnivorous plants: These are predator plants, which capture insects.♦ Partial root parasites e.g., sandalwood tree (Santalum album), Striga lutea. ♦ Total root parasites, e.g., broomrape ( Orobanche indica ), Aeginetia indica, etc. ♦ Partial stem parasites, e.g., Viscum, Loranthus, etc. ♦ Total stem parasites, e.g., dodder ( Cuscuta reflexa ), Arceuthobium, etc. Common examples of different types of phanerogamic parasites are as follows: Parasites: These are the plants, which obtain their nourishment partially or wholly from other living organisms called hosts by their sucking roots.Angiospermic saprophytes are also called humus plants, e.g., Indian pipe ( Monotropa), bird’s nest orchid ( Neottia), chain orchid (Pholidota), coral root ( Corallorhiza), etc. Saprophytes: They obtain their nourishment from dead organic matters.There are, however, many plants, which draw their organic food from different sources and are called heterotrophic plants. Majority of angiospermic plants are autotrophs.Tree having largest crown: Banyan tree (Ficus benghalensis). Tallest plant (angiosperm): Eucalyptus regnans (114 metres or 375 feet height).Arceuthobium is another small angiosperm plant which is parasitic over Pinus and other trees. Smallest angiosperm: Wolffia (0.1mm diameter).These plants usually bear flowers and fruits every year and do not die after producing flowers. Perennials – Survives for several years.They die off after producing flowers and fruits, e.g., Radish, turnip, carrot are biennial in colder areas. Biennials – Complete their life cycle in two years-growing, vegetative and storing food in the first year flowering and fruiting in the second year.They pass the unfavourable period in the form of seeds, eg., Mustard, Pea. Annuals – Complete their life cycle in one year or single growing season or few weeks to a few months.Depending upon their life span, plants are classified as –.It deals with the study of forms and features of different plant organs like roots, stems, leaves, flowers, seeds, fruits etc. Morphology – (Morphe = form + logos = study).
0 kommentar(er)
