To quickly find a word in the glossary, click on the first letter of the word in this list; this will take you to the appropriate spot in the glossary. Then scroll down until you reach the word and definition you seek. If a printer is connected to your computer, you may want to print the glossary by using the print function of your browser.

A ||  B ||  C ||  D ||  E ||  F ||  G ||  H ||  I ||  J ||  K ||  L ||  M ||  N ||  O ||  P ||  Q ||  R ||  S ||  T ||  U ||  V ||  W ||  X ||  Y ||  Z || 


Adventitious. A plant organ (such as a bud, shoot, or root) produced in an abnormal position or at an unusual time of development.
Apical dominance. The influence exerted by a terminal bud to suppress growth of lateral buds.
Apical meristem. Meristematic cells at the apex of a root or shoot.
Asexual propagation. Propagation by using some portion of the plant. Does not involve union of sexual gametes. Equivalent term is vegetative propagation.
Axil. The angle on the upper side of the union of the stem and a leaf, petiole, or branch.
Axillary bud. A bud found in an axil.


Basal plate. The compressed stem axis within a bulb.
Blanch. To bleach or whiten a vegetable as it is growing by throwing soil around the portion to be whitened.
Bud scale. A modified leaf or other structure that encloses and protects a bud.
Bud scale scar. The mark remaining after a bud scale is shed from a stem.
Bulb. A specialized underground organ produced by a monocot that consists of a short, fleshy, usually vertical stem axis with a growing point at its apex or a flower primordium enclosed by thick, fleshy scales.
Bulbil. Miniature aerial bulbs formed in leaf axils.
Bulblet. A miniature bulb formed underground in a leaf axis.


Cold treatment. Exposing a plant to a period of cold of specific temperature and duration.
Contractile root. A root that appears to "pull" bulbs or corms to a given level in the ground.
Corm. Swollen base of a stem enclosed in dry, scale-like leaves.
Cormel. A miniature corm that develops between new and old corms.
Crown. Generally that part of a plant at the surface of the ground from which new shoots are produced. The general transition zone between stem and root.
Crown division. A method of vegetative propagation of perennial plants in which the crown is cut to form more than one plant.
Cultivar. A term used to describe a cultivated variety; but distinguished from the botanical term "variety."
Cure. For sweet potatoes, treatment of the tuberous roots with high temperatures to break apical dominance. The result is increased slip production.
Cutting. Any part that can be severed from a plant and be capable of vegetative propagation.


Differentiate. The process by which cells, tissues, and organs become modified and specialized in the course of development.
Distal. Away from the center or point of origin.
Division. See crown division.
Dormancy. A period of inactivity in bulbs, seeds, buds, and other plant organs.


Eye. An axillary bud on an underground plant part such as a tuber. Eye is also used to describe axillary buds on dahlias in the region where the stem joins the tuberous root.



Growth inhibitor. An organic chemical that circulates in minute quantities in plants and is a primary suppressor of growth.


Hormone. An organic chemical manufactured in minute quantities by plants that is a primary regulator of plant growth and development.


Internode. The region of stem between any two nodes.




Leaf cutting. A leaf that has been severed from a plant and is capable of vegetatively regenerating the plant.
Leptomorph. A slender rhizome with long internodes.



Node. A joint on a stem. May be represented by the point of origin of a leaf or bud, a swollen or constricted ring, or by a distinct leaf scar.
Nontunicate. Refers to a bulb without a naturally occurring tunic.


Offset. A lateral shoot or branch which develops from the base of the main stem in certain plants. Many bulbs produce offsets from their bases.
Offshoot. An alternative term generally equivalent to offset. Applies to lateral branches on stems of monocots. Date palm, pineapple, banana, and orchids produce offshoots.


Pachymorph. A thick, fleshy rhizome that is short in relation to its diameter.
Peg root. Short vigorous roots produced by plantlets that form on stolons.
Perennial. A plant living for many years.
Petiole. Leaf stalk.
Photoperiodism. The reaction of plants to periods of daily exposure to light.
Polarity. A term that refers to orientation of a plant part during its development. For instance, the part of a potato tuber that developed closest to the main stem of the potato plant is termed proximal and the end that developed farthest from the plant is termed distal.
Proximal. Toward the point of origin or attachment.



Rhizome. An underground stem, usually horizontal; distinguished from a root by the presence of nodes and internodes.
Root. The lower portion of a plant that usually develops underground and anchors the plant in the soil; bears the root hairs, which absorb water and nutrients.
Runner. A specialized stem which develops from the axil of a leaf at the crown of a plant, grows horizontally along the ground, and forms a new plant at one of the nodes.


Scaly bulb. A bulb that does not naturally possess dry, membranous outer scales and is composed of fleshy, nonconcentric scales attached to a basal plate; a scaly bulb has perennial roots.
Scooping out. A method of basal cuttage in which the entire basal plate of a bulb is scooped out.
Seed piece. A term used to refer to a section of tuber that has been divided by cutting.
Separation. A vegetative propagation procedure which utilizes the production of naturally detachable structures.
Sexual propagation. Propagation utilizing the fusion of male and female gametes to form a zygote, which forms a new individual.
Slip. An herbaceous cutting from a plant, as in a slip from a sweet potato.
Spur. A short, stubby branch with many nodes.
Stem. The axis of a plant with nodes and internodes; may be above or below ground.
Stolon. Horizontally growing stem that produces adventitious roots, generally when in contact with the soil.
Sugar. A type of carbohydrate manufactured by plants; sucrose is an example.


Translocation. The movement of a substance, such as water or sugars, from one part of a plant to another.
Tuber. A modified stem that develops below ground; develops as a swelling of the subapical portion of a stolon.
Tunic. The dry, membranous outer scales on a bulb, composed of persistent leaf bases (petioles).
Tunicate bulb. A bulb with outer bulb scales which are dry and membranous; scales are in continuous, concentric layers; a tunicate bulb has annual roots.



Vegetative. Concerned with growth and development, not sexual reproduction.
Vernalization. The act or process of causing a plant to blossom early by subjecting it to low temperatures.





  Return to Horticulture 100 home page


McPheeters and Skirvin
University of Illinois
Permission required for duplication