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The vascular cambium is the main growth tissue in the stems and roots of many plants, specifically in dicots such as buttercups and oak trees, gymnosperms such as pine trees, as well as in certain other vascular plants. It produces secondary xylem inwards, towards the pith, and secondary phloem outwards, towards the bark.
Replacement of a tap root system by a fibrous root is seen in onions, tuberose (Polyanthes tuberosa), grasses, etc. Fibrous roots from normal-stem nodes are seen in grasses like maize, sugarcane, bamboo, etc. Fibrous roots from nodes help in the survival of the plant and thus in vegetative reproduction, when the plant's base is damaged or cut ...
Stems of two Roystonea regia palms showing characteristic bulge, leaf scars and fibrous roots, Kolkata, India. Vascular bundles are present throughout the monocot stem, although concentrated towards the outside. This differs from the dicot stem that has a ring of vascular bundles and often none in the center.
Parenchyma is a versatile ground tissue that generally constitutes the "filler" tissue in soft parts of plants. It forms, among other things, the cortex (outer region) and pith (central region) of stems, the cortex of roots, the mesophyll of leaves, the pulp of fruits, and the endosperm of seeds.
Adventitious roots arise out-of-sequence from the more usual root formation of branches of a primary root, and instead originate from the stem, branches, leaves, or old woody roots. They commonly occur in monocots and pteridophytes, but also in many dicots , such as clover ( Trifolium ), ivy ( Hedera ), strawberry ( Fragaria ) and willow ( Salix ).
Aside from cotyledon number, other broad differences have been noted between monocots and dicots, although these have proven to be differences primarily between monocots and eudicots. Many early-diverging dicot groups have monocot characteristics such as scattered vascular bundles, trimerous flowers, and non-tricolpate pollen. [5]
Monocots have a single cotyledon and long and narrow leaves with parallel veins. Their vascular bundles are scattered. Their petals or flower parts are in multiples of three. Dicots have two cotyledons and broad leaves with network of veins. Their vascular bundles are in a ring. Their petals or flower parts are in multiples of four or five.
In dicot root, the vascular cambium is completely secondary in origin, and it originates from a portion of pericycle tissue. [citation needed] The pericycle regulates the formation of lateral roots by rapidly dividing near the xylem elements of the root. [2] It has been known to often be confused with other parts of the plant.