Search results
Results from the WOW.Com Content Network
Botanists define vascular plants by three primary characteristics: Vascular plants have vascular tissues which distribute resources through the plant. Two kinds of vascular tissue occur in plants: xylem and phloem. Phloem and xylem are closely associated with one another and are typically located immediately adjacent to each other in the plant.
Vascular tissue is a complex conducting tissue, formed of more than one cell type, found in vascular plants. The primary components of vascular tissue are the xylem and phloem. These two tissues transport fluid and nutrients internally. There are also two meristems associated with vascular tissue: the vascular cambium and the cork cambium. All ...
Among living plants, this type of stele is found only in the stems of ferns. Most seed plant stems possess a vascular arrangement which has been interpreted as a derived siphonostele, and is called a eustele – in this arrangement, the primary vascular tissue consists of vascular bundles, usually in one or two rings around the pith. [12]
Plant structures, including, roots, buds, and shoots, that develop in unusual locations are called adventitious. Such structures are common in vascular plants. [citation needed] Adventitious roots and buds usually develop near the existing vascular tissues so that they can connect to the xylem and phloem. However, the exact location varies greatly.
This proposed mechanism is a form of plant memory storage. Another potential mechanism involves electrical signals and calcium. When Ca2+ floods the cytoplasm it allows the plant to store a memory, the duration and amplitude of this Ca2+ wave is determined by the type of stimulus that was perceived and how the plant will store the memory. [6]
Cork cambium (pl.: cambia or cambiums) is a tissue found in many vascular plants as a part of the epidermis. It is one of the many layers of bark , between the cork and primary phloem . The cork cambium is a lateral meristem and is responsible for secondary growth that replaces the epidermis in roots and stems .
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.
They are one of the oldest lineages of extant (living) vascular plants; the group contains extinct plants that have been dated from the Silurian (ca. 425 million years ago). [ 2 ] [ 3 ] Lycophytes were some of the dominating plant species of the Carboniferous period, and included the tree-like Lepidodendrales , some of which grew over 40 metres ...