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The basal eudicots are a group of 13 related families of flowering plants in four orders: Buxales, Proteales, Ranunculales and Trochodendrales. [1] [a] Like the core eudicots (the rest of the eudicots), they have pollen grains with three colpi (grooves) or other derived structures, [4] and usually have flowers with four or five petals (sometimes multiples of four or five, sometimes reduced or ...
Basal eudicot is an informal name for a paraphyletic group. The core eudicots are a monophyletic group. [11] A 2010 study suggested the core eudicots can be divided into two clades, Gunnerales and a clade called Pentapetalae, comprising all the remaining core eudicots. [12] The Pentapetalae can be then divided into three clades: [citation needed]
Helianthus stem in section. The cells of the vascular cambium (F) divide to form phloem on the outside, located beneath the bundle cap (E), and xylem (D) on the inside. Most of the vascular cambium is here in vascular bundles (ovals of phloem and xylem together) but it is starting to join these up as at point F between the bundles.
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.
The age of some herbaceous perennial plants can be determined by herbchronology, the analysis of annual growth rings in the secondary root xylem. [18] Herbaceous plants do not produce perennializing above-ground structures using lignin, which is a complex phenolic polymer deposited in the secondary cell wall of all vascular plants. The ...
In the stems of some Asterales dicots, there may be phloem located inwardly from the xylem as well. Between the xylem and phloem is a meristem called the vascular cambium. This tissue divides off cells that will become additional xylem and phloem.
The cork cambium is a lateral meristem and is responsible for secondary growth that replaces the epidermis in roots and stems. It is found in woody and many herbaceous dicots, gymnosperms and some monocots (monocots usually lack secondary growth). It is one of the plant's meristems – the series of tissues consisting of embryonic disk ...
In botany, a cortex is an outer layer of a stem or root in a vascular plant, lying below the epidermis but outside of the vascular bundles. [1] The cortex is composed mostly of large thin-walled parenchyma cells of the ground tissue system and shows little to no structural differentiation. [ 2 ]