Search results
Results From The WOW.Com Content Network
A primary vein, also known as the midrib, is the main vascular structure running through the center of a leaf. [1] The primary vein is crucial for the leaf’s efficiency in photosynthesis and overall health, as it ensures the proper flow of materials and structural integrity.
A space between the threads of a net, e.g. that part of a leaf surface defined by each of the elements of a vein network; as with cacti, the area between the veinlets of a leaf. 2. A structure on the stem node of a cactus , morphologically a specialised branch; the region of a cactus upon which spine s, glochid s, and flowers are borne.
Acrodromous – the veins run parallel to the leaf edge and fuse at the leaf tip. Actinodromous – the main veins of a leaf radiate from the tip of the petiole. Brochidodromous – the veins turn away from the leaf edge to join the next higher vein. Campylodromous – secondary veins diverge at the base of the lamina and rejoin at the tip.
Leaves of most plants include a flat structure called the blade or lamina supported by a network of veins, a petiole and a leaf base; [1] but not all leaves are flat, some are cylindrical. [citation needed] Leaves may be simple, with a single leaf blade, or compound, with several leaflets.
In contrast, leaves with reticulate venation have a single (sometimes more) primary vein in the centre of the leaf, referred to as the midrib or costa, which is continuous with the vasculature of the petiole. The secondary veins, also known as second order veins or lateral veins, branch off from the midrib and extend toward the leaf margins.
In a frond which is pinnate (feather-shaped), each leafy segment of the blade is called a pinna (plural pinnae), the stalk bearing the pinna is termed a petiolule, and the main vein or mid-rib of the pinna is referred to as a costa (plural costae). [6] If a frond is divided once into pinnae, the frond is called once pinnate.
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!
Cross section of celery stalk, showing vascular bundles, which include both phloem and xylem Detail of the vasculature of a bramble leaf Translocation in vascular plants. 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 ...