Class Monocotyledons

Systematic signs of monocots:

The presence of one cotyledon in the embryo

Root system fibrous

Leaves are mostly simple, whole-edged with parallel or arcuate venation.

Three-membered flowers

Liliaceae family - 2 800 species.

Liliaceae are perennial, herbaceous, bulbous or rhizomatous plants.

Flowers are correct, bisexual, single or collected in an inflorescence brush, spike, umbrella, panicle

The perianth is simple, consists of six loose (tulip) or accrete (lily of the valley) leaves. There are usually six stamens, three in a circle, one pistil with a solid or three-lobed stigma.

The fruit is a box or berry. When ripe, the capsules crack into sashes.

Economic value:

Food: onions, garlic, leeks, asparagus, etc.

Decorative: lily, tulip, hyacinth, asparagus, etc.

Medicinal: lily of the valley may, bought medicinal, aloe tree, hellebore.

Cereals family (Bluegrass) - 12,000 species

There are many annuals among cereals, but perennial rhizome plants prevail. The stalk of almost all cereals is solo mine- segmented at the nodes and hollow at the internodes. Corn and sugarcane have a pith in their stems.

The leaves are alternate, with a leaf sheath, with parallel venation. Leafy sheaths serve as protection for internodes, which retain the ability for interstitial growth for a long time. Branching of the stalks of cereals occurs near the base, in the so-called tillering zone, consisting of closely spaced nodes. In the axils of leaves extending from these nodes, buds are laid, giving rise to lateral shoots. Depending on the direction of growth, a turf, a loose bush or a long rhizome with single aerial shoots is formed.

Cereals are wind-pollinated plants; therefore, the flower has a number of adaptations for wind-pollination.

The perianth is simple, inconspicuous, stamens with flexible long filaments and swinging pollen, attached to it by their middle, light dry pollen and feathery stigmas. Some cereals undergo self-pollination. The flower usually has one pistil, three stamens, two flower films and two flower scales. O (2) +2 T 3 P 1

Simple inflorescences - spikelets - are collected in complex inflorescences of the type

Complex ear (rye, wheat, barley),

Ear (corn)

Panicle (oats),

Sultan or false ear (timo-fey)

The fruit of cereals - weevil. The largest part of the caryopsis is endosperm, which contains starch, as well as proteins, fats, vitamins, which explains the enormous practical value of cereals.

Economic value:

Bread, technical: wheat, rye, barley, oats, corn, rice, sorghum, sugarcane

Fodder: fescue, bluegrass, timothy, hedgehog.

Construction: bamboo, reed.

Weeds: creeping wheatgrass, wild oat, bristle grass, barnyard.

Families of the Department of Angiosperms

How are dicotyledonous plants different from monocotyledonous plants? Give at least 4 signs. 1) in dicotyledons there are two cotyledons in the seed embryo, in monocotyledons - one; 2) the root system of dicotyledons is, as a rule, pivotal, and monocots are fibrous; 3) in dicotyledons the leaves are simple and complex, the venation is reticulate, in monocotyledons the leaves are always simple, the venation is parallel and arched; 4) as a rule, in dicotyledonous flowers with a double perianth, four- or five-membered, in monocots - flowers with a simple perianth, three-membered.

On what grounds are plants of the Liliaceae and Cereals families classified as Monocots? Indicate at least 4 signs. 1) a seed with one cotyledon; 2) fibrous root system; 3) simple leaves with parallel or arcuate venation; 4) a three-membered flower with a simple perianth.

Determine the family from the picture flowering plant... Name the type of inflorescence shown. What kind of fruit is typical for this family? 1) the Bluegrass family (Grain); 2) a complex inflorescence - a complex ear; 3) a fruit - a weevil.

Determine the class and family of the angiosperm shown in the picture. What are the types of inflorescences and fruits characteristic of this family? ... 1) class Monocotyledonous plants, Liliaceae family; 2) single flowers or inflorescence - brush; 3) the fruit is a berry or a box.

It is known that in practice agriculture before sowing seeds, check their germination. Explain how and why they do it

1) to determine the germination of seeds, a certain number of them (100) are placed in optimal conditions for germination and the percentage of germinated seeds is calculated;

2) germination is determined to establish the quality of the seed, on which the plant yield depends

Many members of the Rosaceae family have a drupe. What structural features of the fruit ensure the spread of the seeds of these plants? 1) the drupe has a juicy pulp, which attracts animals; 2) the fruits are eaten by birds or mammals, while the seeds are not digested in the digestive canal of the animal and are removed with droppings, which contributes to their spread.

Let's read the information .

Class monocotyledonous plants - plants, in the embryo of the seed of which there is one cotyledon.

Common signsinherent in all angiosperms, including monocotyledonous plants:

• reproduction to form seeds

• always internal fertilization - double

• life phases always successively replace each other (the sporophyte always prevails, and the gametophyte undergoes a strong reduction and develops within the spore)

• all seed plants are heterogeneous

• there is a stage in the breeding process - pollination

The monocotyledonous plant class consists of approximately 65 families.

Consider large families monocotyledonous plants.

Consider the morphological structure of the species Sowing rye .

Adaptation - the ability to adapt to environmental conditions.

Examples of adaptation sowing rye :

1. Rye has a fibrous root system that penetrates to a depth of 2 m. This allows it to grow even on sandy soils and quickly assimilate nutrients from the soil.

2. The rye leaf blade is covered with hairs on the upper side, which indicates a comparative resistance to lack of moisture and adaptability to light sandy soils.

Scientific classification

Kingdom - plants

Department - Angiosperms

Class - Monocots

Order - Mallow

Family - cereals (cereals) or bluegrass

Genus - Rye

View - Sowing rye

Consider comparative characteristics classes .

Used Books:

1. Biology: a complete guide to prepare for the exam. / G.I. Lerner. - M .: AST: Astrel; Vladimir; VKT, 2009

2. Biology: Plants, bacteria, fungi, lichens: textbook. for 6-7 cl. general education. Institutions / T. I. Serebryakova, A. G. Elenevsky, M. A. Gulenkov et al. - 5th ed. - M .: Education, 1999.

3. Biology for university applicants. Intensive course / G.L.Bilich, V.A.Kryzhanovsky. - M .: Onyx Publishing House, 2006.

4. Biology: textbook-reference guide / A.G. Lebedev. M .: AST: Astrel. 2009.

5. Biology. Complete general education course high school: tutorial for schoolchildren and applicants / M.A. Valovaya, N.A. Sokolova, A.A. Kamensky. - M .: Exam, 2002.

Flora is usually divided into monocotyledonous and dicotyledonous plants, differing mainly in the structure of the embryo. Nevertheless, these classes of plants also have other differences in the structure of vegetative and generative organs.

Class Dicotyledons, or Magnoliopsids: the structure of plants and their brief characteristics

Today this class is considered to be quite large, as it includes about 200 thousand species. Its representatives have a number of very characteristic distinctive features.

Dicotyledonous plants presented in different forms - these are trees, and bushes, and herbs. In woody species, inside the stem there is a rather thick layer of cambium - a special tissue that ensures its growth in width. The leaves of plants can be both simple and complex, but in almost all species they are cuttings - sessile leaf blades are not characteristic of this class. The venation of the lamina is in most cases reticular. predominantly pivotal - it has a main, main root, from which lateral ones grow, small size.

Another feature is the structure. Most species have large flowers with bright colors. They have a double perianth (sepals and petals), flowers are predominantly five- or four-membered. Dicotyledonous plants are most commonly pollinated by insects.

And, of course, the structure of the embryo, which has two lateral cotyledons, is very characteristic. By the way, the name of the class is connected with this feature.

Dicotyledonous plants: the most common species

This class includes great amount species that are included in several thousand genera and three hundred families. The most famous of them are the following.

Family Cruciferous - its representatives are distributed mainly in the planets. Most of its species are herbaceous forms or small shrubs. Everyone knows such representatives of crucifers as cabbage, radish, horseradish, turnip, mustard and radish.

The Pink family unites trees, shrubs, and which are mainly found in temperate or subtropical climates. For example, the well-known rose hips and decorative roses belong to this group. This also includes most of the including apple, pear, cherry, mountain ash, raspberry, bird cherry, blackberry.

The legume family - its woody forms and shrubs are distributed mainly in tropical and subtropical countries, and herbaceous ones prefer a more moderate and even colder climate. All members of the group are characterized by a specific "moth" type corolla. This group includes the following famous plants: peas, beans, alfalfa, beans, soybeans. By the way, some species are actively involved in the nitrogen cycle.

Class a brief description of

This group is represented mainly by herbaceous plants - trees and shrubs are extremely rare in it. Their stems, as a rule, do not contain cambium and, therefore, are not capable of growing in thickness. The leaves are simple, with solid edges. They do not have a petiole and are attached to the stem by the edge of the leaf blade, which is why they are called sessile leaves. Venation in most cases is parallel or arched.

Another feature is the fibrous root system, which lacks a main root. There is only one cotyledon in the embryo, as evidenced by the name of the class.

Most of monocotyledonous plants are pollinated by the wind. Therefore, their flowers are small, dim, with a single perianth, mainly three-membered.

Typical representatives of this group are cereals: wheat, oats, corn, rice and others.

In which the embryo of the seed has two lateral cotyledons. Dicotyledons are an ancient large group of plants, many of which have great importance In human life. Among them there are food and fodder crops - potatoes, beets, buckwheat, oil crops - sunflowers, fruit and berry crops -, grapes, as well as medicinal, spicy, fibrous plants and many others.

In addition to two symmetrical cotyledons, Magnoliopsids have other characteristic features... Most often, among them there are plants with a root system, in which the main root is clearly expressed and there are practically no lateral and adventitious ones. In the stems of representatives of this class of Angiosperms, there is a cambium, due to which plants can increase in thickness. Dicotyledonous leaves can be simple or complex, with jagged edges and cuttings. The flowers of Magnoliopsids, four- or five-membered, most often have a double perianth. Among Dicotyledons, it is distributed by insects.

Monocots

Scientists are inclined to believe that Monocots, or Lileopsids, are a younger class of plants descended from Dicotyledons. This class is less numerous than the previous one, but it also has many representatives. Monocots include Liliaceae, Asparagus, Orchid, Sedge, Palm, Cereals. The main difference between this class is that the seed embryo in Lileopsids has only one cotyledon.

There are other features of this group that are easier to see with the naked eye. The root system of most Monocots. The main root rather quickly ceases to develop, but numerous adventitious and lateral roots... As a rule, there is no cambium in the stems of Lileopsids, so they are thin and unable to grow in thickness. While among the Dicotyledons there are herbaceous plants, trees, representatives of the Lileopsida class are herbaceous plants and very few trees. The leaves of these plants are simple, without. As a rule, they are long, as they grow for some time due to the educational tissue located at their base. In Monocots, three-membered flowers with a simple perianth are most often found, because few representatives of this class have to attract insects for. Usually Monocotyledonous pollen resorts to the wind.

Characteristics of the Buttercup family

Department. Magnoliophyta - angiosperms

Class. Magnoliopsida - dicotyledonous

Subclass. Ranunculidae - ranunculids

Order. Ranunculales - buttercup

Family. Ranunculaceae - buttercup

Kinds :

Trollius europeus - european swimsuit

Pulsatilla patens - open backache

Anemone silvestris - forest anemone

Delphinium elatum - high larkspur

Aconite napellus - real aconite

Adonis vernalis - spring adonis

Ranunculus acris - caustic buttercup

Life form: annual and perennial herbaceous plants, less often shrubs.

Root system: fibrous, some species have rhizomes and tubers.

Leaves: simple, without stipules, finger- or pinnately dissected or separate, some species form a rosette of basal leaves.

Leaf location: next.

Inflorescences: cymoid in the form of monohasia and botryoid brushes and panicles.

Flowers: actinomorphic, less often zygomorphic, acyclic or hemicyclic, with a simple or double perianth, androecium always consists of an indefinite number of free stamens, gynoecium apocarpous, consists of a large number of carpels, less often of 5, 3, 1. Ovary top.

Flower formulas:

european leotard * R ∞ A ∞ G ∞

open backache * P 6 A ∞ G ∞

forest anemone * P 5 A ∞ G ∞

larkspur high  Сa 5 Co 3 + 2 A ∞ G 3

aconite real  Ca 5 Co 6 + 2 A ∞ G 3-7

spring adonis * Ca 5 Co ∞ A ∞ G ∞

caustic buttercup * Ca 5 Co 5 A ∞ G ∞

Fetus: apocarp: multileaf or manynuts.

BAS: cardiac glycosides, alkaloids, flavonoids, etc.

Distribution and habitat: in temperate regions of the northern hemisphere, mainly in meadows and forests.

Features: a lot of poisonous plants... It is possible to trace the evolution of buttercup flowers, which went in the direction of adaptation to pollination by various pollinators: from acyclic flowers with a simple perianth and an indefinite number of flower parts to heicyclic flowers with a double perianth and with a strictly defined number of perianth parts.