As a rangeland manager, you will need to know range plants by their names and have an understanding of plant communities and community succession. Plants tell you what kind of range you have. Each plant helps to tell the story. The presence or absence of certain plants in the range tells how the range has been used and what should be done for improvement or maintenance.

Range plants include trees, shrubs, grasses, grass-like plants, forbs and vines. Some have thorns, others sting when touched and still others have no immediately noticeable form of self-defense. Some plants grow in dry places; others live in wet places such as wetlands.

Certain rangeland plants, particularly grasses, grass-like plants and shrubs, are the most efficient plants for catching and holding moisture where it falls on rangeland. Vigorous, deep-rooted grasses are one of the most effective for this purpose. Grasses have many fibrous roots; some are shallow, some are deep. Some of the roots die and are replaced each year when plants are vigorous. The dead root furnishes food for soil organisms. When a root dies, it leaves a small channel, which water can move through into the soil.

All rangelands, however, are not best adapted to grass production. For example, we have ponderosa pine-grass sites where the tree-grass combination makes best use of the site. Also, there are shrub-grass sites and grass-forb sites, where different combinations of plants represent best use of a given site. It is a responsibility of the rangeland manager to recognize the site differences and to apply appropriate management methods.

Parts of Plants

Plants, like people, have bodies and parts. Each plant has some parts that are different from all other plants. Because grasses are the most important group of range plants, we will learn the parts of grass and compare grass with other plants.

Plants usually have roots, crowns, stems, leaves and seedheads. To tell one plant from another, you must know the names of the main parts and their differences. Roots, unlike stems, have no joints, leaves or flowers. The root’s growing part is at the tip. The main functions of the roots are to take water and minerals from the soil to the stems, to store food over winter for spring growth and to anchor the plant to the soil.

Rhizomes are actually creeping underground stems with joints and leaf-like scales. You may have seen quack-grass or western wheatgrass rhizomes producing a new plant. Rhizomes store food and reproduce new plants. Stolons are like rhizomes, except they grow above the ground. They do the same job as rhizomes (food storage and reproduction).

Above ground, a plant may be divided into vegetative and flowering parts. Vegetative plant parts include the stems and leaves. The grass stem is made up of nodes (joints) and internodes (between the joints); it is usually hollow but sometimes has pith in the center, similar to corn. The main functions of the stem are to transport water, minerals, and food between the roots and the leaves and to support the leaves.

At each node on the stem, there is a bud that may reproduce a branch or remain dormant. The leaf also arises from a node on the stem. It is made up of two parts: the sheath, which fits closely around the stem, and the broad, expanded portion known as the blade. These two parts are jointed together at the collar, which has two parts. On the inside of the collar, next to the stem, is a small leaf-like projection known as the ligule. On the outside of the collar, on some grasses, are two ear-shaped tips that clasp the stem. These tips are called auricles.

The growing point of the grass leaf is at the base of the leaf and sheath rather than at the tip. That explains why grass leaves can be grazed and continue to grow and produce forage. The growing point of herb stems is at the tip. When the tip is grazed or clipped off, the stem quits growing.

The ‘flower’ or head of a grass plant is made up of many smaller units known as spikelets. At the base of each spikelet there are two leaf-like bracts known as glumes. When there is more than one floret (single grass flower) in each spikelet, each floret is supported on a short stem known as a rachilla. Each of these florets at maturity produces a seed. The seed is enclosed by two more leaf-like bracts known as the lemma and palea. In many grasses, such as bluebunch wheatgrass, the lemma and palea remain with the seeds after they ripen and fall.

If you do not have an identification key and need to know the name and importance of a plant, take the plant to your county extension (agricultural) agent or to some other range technician. If they cannot identify it for you, keep one specimen and send another one to your extension range specialist or to the herbarium of your state university. When collecting for identification, you must collect the entire plant. It will also aid in identification if you press each specimen. (See the section on collecting rangeland plants) Number each plant. Numbers are used by herbarium workers in giving you the requested information.

How Plants Live and Produce

Range plants are living organisms that require nutrients, minerals, air, water and light in order to live and produce tops, roots and seeds. If any one of these elements is cut off, the plant will die.

A green plant is nature’s food-manufacturing machine. For power, it uses energy from the sun. Water, air and minerals are the raw materials used in this manufacturing process. Some finished products are sugar (an energy source) and protein (needed for growth). Waste products are oxygen, carbon dioxide and water.

Water
Water makes up about 70% to 90% of the weight of green grass and from 8% to 25% of dry grass. Evaporation of water from the plant leaves helps the plant to keep cool. Water also serves as a food and mineral carrier within the plant’s body.

Water is absorbed into plants through the roots. The young, tender leaves contain more water and nutrients than any other part of the plant. Grasses, like of the plants, need large amounts of water to produce a pound of dry forage. In the semiarid areas, range grasses need from 300 to 1,000 pounds of water to produce one pound of dry forage, while shrubs and trees need 1,700 to 2,400 pounds to produce a pound of twigs, bark and leaves.

Air
Carbon dioxide taken from the air is another material required for manufacture of plant food that is needed for grass growth. The plant takes in the carbon dioxide through stomata (very small holes) on the underside of the leaves. Inside the plant cells, the carbon dioxide, together with other raw materials, is made into starches, sugars, fats and protein. Green plants give off oxygen while they are in the process of making food. This process helps replenish the atmosphere with breathable oxygen for the earth’s animals.

Minerals
Many mineral elements are found in plants. It is not known if all minerals found in plants are required for growth, but many of them are certainly essential. The three major elements required by plants are nitrogen, phosphorus and potassium. Other minerals needed in varying amounts are calcium iron, sulfur, magnesium, cobalt, manganese, zinc, boron, molybdenum and chlorine.

Each mineral element has a definite place in the life of a grass plant. A plant uses nitrogen in the manufacture of protein, which is vital to plant growth and reproduction. Nitrogen is in a free state in the air, but as such, cannot be used by plants. Soil organisms take nitrogen from the air, combine it with other elements and deposit it in the soil. Plants then get their nitrogen supply from the soil.

Calcium acts as a cement or glue to hold the cell walls of plants together. It forms a protection around each cell, allowing plant nutrients to enter but keeping out injurious particles.

Phosphorus is needed for rapid cell division, food making, seed development and production of a strong, healthy plant. Phosphorus seems to be especially important in helping plants develop a strong root system.

Potassium is a mystery mineral. However, it is apparently needed to assist sunlight in forming other compounds necessary for plant life. Each of the other minerals also serves a purpose.

Remember, ‘it takes grass to make grass’. It is the plant tops or shoots where the food is manufactured and the building materials for the roots and tops are made.

Common Rangeland Plants

Rangeland Plant Guides: Idaho Native Plant Society

Since plants have different life spans, they can be grouped according to how long they live and how they grow.

Annual plants live only one season. They must reproduce each year form seeds. They do not grow a second year from roots or crown.

Biennial plants live two years and reproduce by seeds the second year.

Perennial plants live over form year to year, producing leaves and stems for more than two years from the same crown. These plants reproduce by seeds, stems, bulbs and underground rootstocks. There are both short-lived and long-lived perennials.

Not all plants are native to our locality, state or country. Some have been brought in accidentally or purposefully from other areas or foreign countries.
Plants are native to a region if they had their evolutionary beginnings in that region. Introduced plants are those that have been brought in from outside the region relatively recently.

Plants grow in different seasons of the year. Cool-season plants make their principal growth during the cool weather in the spring or late fall. Warm-season plants generally make their principal growth during the frost-free period and develop seed in the summer or early fall (since they wait for warm weather).

Plants are also grouped according to their growth form, that is, their shape or how they look as they grow. Because range plants are so numerous and so different in their forms and growth habits, they should be grouped for convenience in range management. There are six main kinds of plants: grasses, grass-like plants, forbs, shrubs, half-shrubs and riparian/wetland plants. Following is a description of the kinds of common upland range plants:

Grasses. Plants with jointed stems; stems are generally hollow; leaves are in two rows on the stem; veins on the leaves are parallel. These are ‘true grasses’ and are among the most important kinds of range plants. Examples are:
Bluebunch wheatgrass (perennial bunchgrass)
Quackgrass and western wheatgrass (perennial with creeping underground stems or rhizomes)
Cheatgrass (annual grass)

Grass-like plants. These plants look like grass, but have solid (not hollow) stems that are often triangular and have no joints. Veins are parallel in the leaves. These are sedges and rushes. Examples are:
Elksedge (triangular in cross section)
Baltic rush (round in cross section)

Forbs. A forb is a non-grass-like plant with annual stems 9tops). There are netlike veins in the leaves. Examples are weeds and range flowers. We use the term ‘forb’ instead of ‘weed’ because weeds are best thought of as undesirable plants. Many of this group of range plants are not pests, for they are valuable as forage, especially for sheep and wildlife. Examples are:
Yarrow (perennial creeping rhizomes)
Tapertip hawksbeard (perennial roots)
Bull thistle (biennial roots)
Tumble mustard (annual forb)

Shrubs. A shrub is a woody plant; its stems and buds live over the winter above the ground and branch from near the base (a tree resembles the shrub in growth form, but the tree has a definite trunk with branches well above the ground). Examples of shrubs are:
Big sagebrush
Rabbitbrush
Bitterbrush

Half-shrubs. A half-shrub is a perennial plant that dies back each winter, not to the ground line, but to a perennial woody base or a bare ground stem. Examples are:
Matchweed
Winterfat

Riparian/wetland plants. These plants can be in the form of any of the five types listed above, or may be trees, but are specially suited to, and are most commonly found in, riparian areas.
Cottonwood (tree)
Willow (tree/shrub)
Saltgrass
Nebraska sedge (grass-like)
Western Aster (forb)

By knowing the groups of plants and plant parts, you can use an identification key. A key is an organized listing of plant characteristics according to structure (generally, flower parts). Plant keys are helpful in determining the correct names of plants. See your county Extension agent or rangeland technician for a key to range plants in your county or state.

Forage Value

Forage value for each species can be determined on the basis of preference (how well it is liked by livestock and/or wildlife), nutritive content and dependability as a forage supply. This is a relative factor that may vary, depending upon the kind of livestock or wildlife using the plants, the soil fertility and the season. Forages may be classed desirable or undesirable.

Cattle especially like to graze grass that is high enough so they can wrap their tongues around it and get a big bite. Early in the spring the taller grasses are soft and the livestock prefer them. Cattle can fill up quickly if they have taller growing grasses to graze. If they are forced to eat short grasses, they get less to eat and gain less. Cattle also eat some forbs and shrubs, especially in late summer.

Sheep and goats are browsers. They like fine grasses, forbs and shrubs. Sheep like forbs and shrubs better than cattle do; this is even truer of goats. Knowledge of the kind of plants growing on your range will help you decide what kind of livestock to select.

See Also: Rangeland Noxious Weeds and Invasive Species