These nematodes, sold under the names of Scanmask and Nemasys, are microscopic, wormlike creatures that will destroy the fungus gnats but are not harmful to people, pets, plants, or earthworms. These products can be used whenever the soil is not frozen and will keep working for many months.
Vegetative structures. There are three levels of integrated organization in the vegetative plant body: organ, tissue system, and tissue. The organs of the plantâthe roots, stems, and leavesâare composed of tissue systems (dermal tissue, ground tissue, and vascular tissue; see below Tissue systems).
Differentiate among the types of plant tissues and organs. There are two types of plant tissues: meristematic tissue found in plant regions of continuous cell division and growth, and permanent (or non-meristematic) tissue consisting of cells that are no longer actively dividing.