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Crop Identification



During the contest you will have 30 minutes to identify crops. Review the above slide show to see pictures of the different types of crops. A PDF copy is available for download.

The production of field crops, including cash crops, pastures and forage crops, is of major importance on practically all Louisiana farms. We depend on plants to convert the sun's energy into food, feed for livestock and useful fiber. The direct sale of many crops contributes a major portion of our farm income. Other crops are grown for grazing, feeding livestock and cover crops.

The ability to recognize and identify plants is of importance to most citizens regardless of their occupation. They may have frequent contact with plants at work, around the home or during leisure activities. Farmers and ranchers may have daily contact with many plants, some of which are valuable crops, some are undesirable competitors with crops and some are toxic. It is helpful to be able to recognize or identify plants that we see around us. The field crop identification phase of the 4-H Plant Science 4-H U contest will include the identification of plant specimens and a portion of the test will cover crops. Test questions will be either multiple choice or true/false. They will be taken from this article and from the publications "Enter the World of Plant Science" and "Enjoy the World of Plant Science." Sample test questions are below.

For the identification of crops, you must be familiar with the common name and the scientific name of 30 crops. You also must know if the crop is an annual, a biennial or a perennial and whether it is a warm-season crop (summer growing) or a cold-season crop (fall, winter and spring growing).

For identification purposes, flowering plants are divided into two subclasses: monocotyledoneae and dicotyledoneae. Monocots have one seed leaf or cotyledon present in the embryo of the seed, and dicots have two cotylendons.

Monocots and dicots are further divided into groups of closely related plants called families. From a field crop standpoint, the most important group of monocots is the grass family and the most important group of dicots is the legume family (Legumino retIs). Examples of grasses are wheat, corn, sorghum, oats, rice, sugarcane, tall fescue, ryegrass, Bermudagrass and pearl millet. Examples of legumes are alfalfa, red clover, soybeans, peanuts, hairy vetch, lespedeza and field beans.

This study material should help you learn to identify and recognize field crops. You should become familiar with this information before the contest.

List of field crops to be used in crop identification phase of the plant science contest

Common Name -- Scientific Name -- Life Cycle
A= Annual         P=Perennial

  1. Rice -- Oryza sativa -- A
  2. Soybeans -- Glycine max -- A
  3. Cotton -- Gossypium hirsutum -- A
  4. Corn -- Zea mays -- A
  5. Sugarcane -- Saccharum officinarum -- P
  6. Grain Sorghum -- Sorghum bicolor -- A
  7. Wheat -- Triticum aestivum -- A
  8. Oats -- Avena sativa -- A
  9. Sunflower -- Helianthus annuus -- A
  10. Sweet Sorghum -- Sorghum bicolor -- A
  11. Rapeseed -- Brassica napus -- A
  12. Peanuts -- Arachis hypogaea -- A
  13. Annual Ryegrass -- Lolium multiflorum -- A
  14. Tall Fescue -- Festuca arundinacea -- P
  15. Dallisgrass -- Paspalum dilatatum -- P
  16. Bermudagrass -- Cynodon dactylon -- P
  17. Bahia grass -- Paspalum notatum -- P
  18. Johnsongrass -- Sorghum halepense -- P
  19. Pearl Millet -- Pennisetum americanum -- A
  20. Alfalfa -- Medicago sativa -- P
  21. White Clover -- Trifolium repens -- P
  22. Red Clover -- Trifolium pratense -- P
  23. Subterranean Clover -- Trifolium subterraneum -- A
  24. Crimson Clover -- Trifolium incarnatum -- A
  25. Berseem Clover -- Trifolium alexandrinum -- A
  26. Hairy Vetch -- Vicia villosa -- A
  27. Singletary Pea -- Lathyrus hirsutus -- A
  28. Arrowleaf Clover -- Trifolium vesiculosum -- A
  29. Common Lespedeza -- Lespedeza striata -- A
  30. Alyceclover -- Alysicarpus vaginalis -- A

Click here for a study guide containing the descriptions of plants for field crop identification section.

Glossary

Alternate .. Situated single at each node, as leaves on a stem or flowers along an axis.

Auricle .. Clawlike appendages at the edges of the collar of a grass leaf (finger like projections). 

Axil .. The position or angle between a lateral organ, especially a leaf, branch or pedicel, and the axis of the stem.

Blade .. The flattened portion of the leaf that extends outward from the sheath in grasses or the petiole in roots.

Collar .. The point at which the sheath and blade of a grass leaf join.

Compound (leaf) .. Composed of two or more separate leaflets.

Cool-Season Plants .. Plants that have most rapid growth at temperatures of 77-87ºF. In Louisiana, the fall and spring seasons are periods of fastest growth for such plants.

Culm .. The stem of a grass.

Dicot (Dicotyledon) .. Plants having two cotylendons or seed leaves. They typically have veins in the leaves that are branched rather than parallel, and the root system has a taproot or main root.

Dioeclous .. Bearing staminate (male) and pistillate (female) flowers on separate plants.

Fibrous .. like fiber -- the fine roots of grass.

Glabrous .. Lacking pubescence (hairs); smooth.

Inflorescence .. A complete flower cluster, including the axis and bracts. 

Leaflet .. A single segment of a compound leaf.

Legumes .. A family of plants having a fruit that is a legume or pod with the seed arranged in one row. Members of this family of plants are capable of drawing nitrogen from the air, with the aid of certain bacteria in their roots, and using the nitrogen for their own growth.

Ligule .. A membrane or row of hairs found at the junction of the leaf sheath and the leaf blade of many grasses.

Monocot (Monocotyledon) .. Plants having a single cotyledon or seed leaf. Veins in their leaves are parallel, and the roots system is fibrous.

Node .. A stem joint.

Opposite .. Situated diametrically across from each other at the same node, as leaves, flowers, or branches along a stem.

Palmate .. A compound leaf design in which all the leaflets are attached at one point to the central stalk or pedole.

Panicle .. A compound or branched inflorescence with each branch bearing a group of flowers.

Pedicel .. The stalk of a single flower in an inflorescence.

Peduncle .. The portion of a stem which bears an inflorescence or a solitary flower.

Pinnate .. Having branches or lobes or leaflets or veins arranged on two sides of a rachis.

Pubescent .. Covered with fine soft hairs.

Raceme .. An inflorescence, with the main axis having stalked flowers, these opening from the base upward.

Rachis .. The central axis of an inflorescence.

Rhizome .. A horizontal underground stem capable of producing a new plant at its nodes and tip. .

Sheath .. The lower portion of a grass leaf that is attached to the stem at the node and usually encircles or surrounds the stem from the node to the collar.

Simple (leaf) .. A leaf which consists of a single leaf blade and is not divided into smaller separated sections.

Spike .. A type of inflorescence in which all the flowers are attached directly to the mail axis or racbis. They have no pedicels.

Spikelet .. The individual flowering unit·or duster of grasses. It typically contains two leaflike bracts or glumes at its base and one to many florets (grass' flowers).

Stolon .. A horizontal aboveground stem capable of producing new plants at its nodes and tip.

Warm-Season Plants .. Plants that have most rapid growth at temperatures of 88-99ºF. In Louisiana, the summer season is the period of fastest growth for such plants.


Last Updated: 1/16/2013 10:34:14 AM

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