This document provides an overview of plant taxonomy including its objectives, main references, and course syllabus. It discusses key concepts in plant taxonomy such as identification, classification, and nomenclature. It also summarizes several important plant families including Asteraceae, Fabaceae, Poaceae, Brassicaceae, Apiaceae, Lamiaceae, and Rosaceae. Methods of plant taxonomy are outlined including morphology, floristics, herbaria, and botanical gardens. The importance of field observation and a region's flora are also noted.

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Practical Plant Taxonomy
Overview: It is very important as complementing and giving support to
the theoretical course. Students need to have some practice both in lab
activities about the topic and field observation.
Objectives: Learning some methods of plant taxonomy & getting
familiar with plant morphology, classification, identification,
nomenclature, flora, herbaria, botanical gardens, phylogeny &
phytogeography.
Main References:
Simpson, M. G., 2006, Plant systematics. Elsevier Academic Press.
Canada.
Lawrence, G. H., 1951, Taxonomy of vascular plants. Oxford & IBH /
Macmillan, New Delhi, India.
Lawrence, G. H., 1955, An introduction to plant taxonomy. Central
Book Depot / Macmillan, India.
‫ا لموسوى، علي حسين، ٧٨٩١ ، علم تصنيف النبات. جامعة بغداد‬
Pandey, B. P., 2005, Modern practical botany, S. Chand, India.
Pandey, B. P., 2000, Taxonomy of angiosperms. S. Chand, New Delhi.
Hickey, M., & C. King, 1997, Common families of flowering plants,
Cambridge U. P.
Tounsend, C. C., E. Guest, et al. 1966-85, Flora of Iraq, 6 volumes,
Iraqi Min. of Agr., printed at Glasgow, U. K.
Kumar, S.. A textbook of plant taxonomy, Campus Books International
India.
Plant Taxonomy Course Syllabus
1. Introduction. 2. Plant morphology. 3. Selected common Eudicot
families. 4. Selected common Monocot families. 5. Field and herbarium
techniques. 6. Selected economic plants. 7. Taxonomic literature & flora.
8. Plant distribution, ecology and geography. 9. Other taxonomic criteria.
10. Evolution, phylogeny, genetics, and plant breeding. 11. Paleobotany.
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Introduction
Plant taxonomy (systematics): is the science of plant identification,
classification and nomenclature.
Identification: is the decision on the identity of a plant by putting it in a
known described species.
Classification: is putting the plant categories in a systematic order of
classes (taxa, sing. taxon).
Nomenclature: is the giving of scientific names to plant populations
and taxa of different levels.
A species (plural also species): is a distinct plant population of the same
genetic origin and is a basic unit of taxonomy.
The Plants Classification
Domain Eukaryota = Eukarya
Kingdom Plantae
Phyla of: I Nonvascular plants (e.g. Bryophyta, .. etc.).
II Vasculars without seeds (e.g. Polypodiaceae, .. etc.).
III Gymnosperm vascular seed plants (e.g. Pinaceae, ..etc.).
IV Phylum Anthophyta = Magnoliophyta = Angiospermae
(The Flowering, vascular seed plants)
Dozens of Orders of:
1 Eudicots = (formerly, Dicots).
2 Monocots.
3 Some small primitive orders.
Hundreds of Families.
Thousands of Genera.
Hundreds of thousands of Species.
Some Infra-specific ranks.
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Some Selected Eudicot and Monocot Families
Order I. Asterales
Family 1. Asteraceae = Compositae
Ref.: Simpson, p. 326.
Special Characters
1. Predominantly herbs.
2. Flowers are arranged in a head called a capitulum (a mass of small
florets on a disk surrounded by special bracts called (involucre).
3. Flowers are typically bisexual, some are unisexual.
4. Two kinds of flower are present: (a) Disk flowers, actinomorphic
symmetry, united petals (gamopetalous) without ligules. (b) Ray
flowers, zygomorphic, gamopetalous with ligules.
5. Calyx (sepals) is modified to pappus.
6. Corolla (petals) is pentamerous (5 parts).
7. Flower parts are epigynous (inferior ovary).
8. Ovary of 2 carpels, 1 chamber, & one seed
9. Placentation is basal.
10. Stamen number 5.
11. The fruit is a kind of achene called cypsela, and is distributed by the
pappus with the wind.
Distribution
It is the largest eudicot family of the world. It has about 1000 genera, &
20,000 species, found everywhere in all habitats.
Economlc importance
Helianthus annuus , sunflower, a food oil crop.
Lactuca sativa, lettuce.
Carthamus tinctorias, oil and dye yielding.
Gundelia tourneforte, thistle.
Some ornamentals are Calendula, Dahlia, & Aster.
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Asteraceae
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Ateraceae
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Asteraceae
.Asa
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Asteraceae
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Order 2. FABALES (Leguminales)
Family 2 Fabaceae (Leguminosae, Papilionaceae) –
Bean/Pea family
643 genera/ 18,000 spp. They are herbs, shrubs, trees, or vines. Roots of
many members have a symbiotic association with nitrogen-fixing
bacteria (Rhizobium spp.), which induce formation of root nodules.
Leaves are usually compound (pinnate, bipinnate, trifoliolate, palmate),
or simple, arranged spirally. Inflorescence is variable. Flowers are mostly
bisexual, zygomorphic (corolla apopetalous or sympetalous, 5
papilionaceous petals). Stamens are 10 (1+9). Gynoecium has 1 carpel,
with a superior ovary, and1 locule. Style and stigma are solitary.
Placentation is marginal; ovules are 2- ∞/ carpel. Nectaries are a ring at
the base of ovary. Fruit is a legume.
The Fabaceae is a very large group with a worldwide distribution, and
ecologically important for containing nitrogen-fixing rhizobial nodules.
Economically, legumes are important plants, being the source of
numerous pulses: such as:
a. Arachis hypogaea, peanut; b. Glycine max, soybean; c. Lens
culinaris, lentil; d. Phaseolus spp., beans; e. Pisum sativum, pea. f.
Vicia faba, broad bean, .. etc.
Fodder and soil rotation plants are: a. Medicago sativa, alfalfa; b.
Trifolium spp., clovers, ..etc. Oils, timber trees, gums, dyes, and
insecticides are also important products of this family.
K 5 or (5) C 5 or (5) A 5, 10, or ∞ G 1, superior, placentation
marginal.
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• Fabaceae
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Fabaceae
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Order 3- Poales (Graminales)
Family 3- Poaceae (Gramineae)
The Cereals Family
This is the most important family of the plant kingdom to humans all
over the world and along their extreme old history. Still now our bread,
sugar, rice, oil, starch and many other food materials are inside this group
of plants.
This is a monocot family of mostly herbs called grasses, few shrubs are
also included. Roots are fibrous; leaves simple linear, parallel-veined,
sheathing hollow stems at bases. The inflorescence is a compound spike
or a compound panicle of spikelets. A spikelet is composed of 1, 2, or
more florets. Flowers are unisexual or bisexual, within some special
bracts called glumes, perianth not found, stamens are 3. Fruit is a
caryopsis, a special dry fruit of 1 seed, where fruit and seed coats are
united.
Economic importance:
Wheat, Triticum aestivum, T. durum, etc.
Barley, Hordeum spp.
Rice, Oryza sativa.
Corn, Zea mays.
Sugar cane, Saccharum officinalis.
Ecologically also this family comprises the most great amount of green
food available on land to all herbivorous animals, and a great part of the
photosynthetic plant mass of the world, by their vast numbers of species
and huge numbers of populations and individuals of the species.
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Poaceae
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Poaceae
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Order 4- Brassicales ( = Cruciales)
Family 4- Brassicaceae (Crucifera)
This eudicot group is well known from old times, they are characterized
by cross-like petals (cruciform corolla), of 4 distinct parts. Most of them
are herbs, many with storage roots. Stems and leaves are hairy and most
plants have acrid, pungent or bitter taste due to many organic products.
Flowers are bisexual, stamens 6, ovary of 2 carpels. Fruits are dry, open
lengthwise into 2 parts.
Most of crucifera grow everywhere as weeds. Some of them are
vegetables:
Brassica oleracia var. cpitata, cbbage; B.napa, turnip; Raphanus sativus,
Rdish.
Order 5- Apiales (Umbellales)
Family 5- Apiaceae (Umbeliferae)
This is the celery family (Apium) or the carrot (Daucus carota). It is
well-known all over the world. Most of them are herbs of aromatic taste
and flavor and many of them are known as spices. Leaves are compound.
Inflorescences are compound umbels. Flower is pentamerous. Fruit is a
schizocarp of 2 separated dry carpomeres.
Vegetables included are:
Celery, Apium graveolens; Parsley, Petroselinum; Dill, Anethum; and
Carrot, Daucus carota.
The spices include many genera and species like:
Carum,Cuminum, Coriandrum, etc.
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Brassicaceae
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Apiaceae
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Order 6- Lamiales
Family 6- Lamiaceae (Labiatae)
Mint Family
This family is one of the well-known plant groups from old ages. Many
members have been used as medicinal herbs, spices, food products or
ornamentals.
Most of them are herbs. Hairy vegetative parts have perfumed glandular
trichomes giving different volatile oils. Stems are recognized by quadrate
appearance (square sections). Flower is well distinguished by its labiate
(or bilabiate) corolla tube, of 5 united petals. Ovary has 4 chambers, each
with 1 seed.
Useful medicinal, spice, perfume and ornamental plants in this family
are:
Mints, Mentha spp. ;
Thyme, Thumus spp.;
Basil, Ocimum spp.;
Rosemary, Rosmarinus spp.
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Me
ntha sp.
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Lamium
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Order 7- Rosales
Family 7- Rosaceae (Rose Family)
This family is mostly herbaceous but contains some trees and shrubs.
Leaves are simple or compound. Flower is pentamerous but may have
numerous petals (5, 10, ..25 .. or more) . A structure called hypanthium
composed of receptacle parts united to some flower parts, after that
becomes a part of the fruit. This fruit is called a pome, e.g. apples. Ovary
may be 1 or more in 1 flower. Stamens are always numerous. Another
kind of fruit here is a drupe, e.g. apricots. Some have aggregate fruits
from union of many ovaries of one flower (strawberry and blackberry).
Economic important plants of this family are:
Fruit trees of :
Apples, Malus spp. ; Pears, Pyrus spp. ; Almond, Amygdalus spp.
Apricot, Prunus armeniaca; Peach, P. persica; Plums, Prunus spp.
Other plants are;
Strawberry, Fragaria sativa; Roses, Rosa spp.; etc.
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Rosaceae
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Plant Morphology
Plant morphology is the science of external study of the plant body
structure, shape and composition. It studies the plant’s habit, i.e. shape of
the plant body. Habit may be a herb, bush, shrub, tree, or vine. Plants are
herbaceous or woody, (some herbs are also woody). Herbs are annual,
biennial, or perennial. Shrubs, trees and vines are evergreen or deciduous
(shed leaves in winter).
Morphology includes the study of roots, stems, leaves, inflorescences,
flowers, fruits, and seeds. It studies the organs’ shapes, structure, kinds,
parts, and modifications. Most the attention is to flower parts, and the
high diversification in their structure, number, shape, color, and special
modifications to different reproductive function types and environments.
Morphology also deals with different adaptations to methods of
perennation (wintering), pollination, and distribution. These are related
to anatomy, physiology, genetics, evolution and ecology. Morphology is
a separate branch of botany, but is also studied in taxonomy, for its
importance to classification methods.
Laboratory activities in plant taxonomy include:
-Observation of plant specimens, fresh and dried, macroscopically and
microscopically in morphology, anatomy and some physiologic aspects.
-Practice of some methods of plant preservation, drying, and keeping.
-Practice of some classification methods using keys of local plants.
-Taking some ideas about work in a herbarium, e.g. arrangement,
keeping, and maintenance.
Field observation is very important in plant taxonomy to recognize the
actual plant populations in the natural habitat. Plant ecology, sociology,
and geography are closely related topics to taxonomy and their relations
are well understood only in the natural habitat.
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Methods of taxonomy are morphological, anatomical, physiological,
cytological, molecular, chemical, ecological, etc.
A Flora means the sum of the plants growing together in a region in a
time. We can speak of the flora of our country as a particular group of
plants different from floras of other places. Each part of a country may
have a different flora, and may have some common plants with other
parts. A Flora also means a book that contains lists, descriptions and
details of the flora of any place. So “The Flora of Iraq” is one of the most
useful documents of this area, (see list of references). The study of flora
is called floristics.
A Herbarium is a kind of national museum of the plants of a country
dried and kept in a preserved state. There are many large and famous
herbaria in all the countries of the world. They contain dry specimens of
all known plants stored for centuries without damage. There are special
techniques of field and herbarium sampling, drying, arrangement and
maintenance. Chemicals are used against pests and international rules are
there for herbarium keeping. Seed banks and gene banks are also parts
of many herbaria which keep thousands of specimens available to world
students and botanical researchers.
Botanical gardens are other international and regional scientific
foundations of very great importance. They are artificial habitats for most
of the wild plants of the world, grown and maintained in experimental
methods for research purposes.
Phylogeny is the principle of the evolutionary relationships between
the taxonomic groups of plants revealed by DNA, fossils, and other
modern studies. Paleontology, embryology, and plant geography give
good evidence on phylogenetic relationships.
Phytogeography means the plant geography. It deals with the world-
wide distribution of plants according to ecological and environmental
factors and studies the differences between various floras.
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Some Common Monocot Orders & Families
With some economically important examples:
I. Asparagales:-
1. Alliaceae: Onion, Allium cepa ;
Garlic, A. sativum;
Leek, A. ampeloprasum.
2. Amaryllidaceae: Daffodil, Narcissus spp.
3. Iridaceae: Iris, Iris spp.;
Saffron, Crocus sativus.
4. Orchidaceae: Vanilla, Vanilla planifolia;
Orchids, Orchis spp.
5. Asparagaceae: Asparagus, Asparagus officinalis.
II. Liliales:-
6. Liliaceae: Lilies, Lilium spp.
Tulips, Tulipa spp.
III. Arecales:-
7. Arecaceae: Date palm, Phoenix dactylifera;
Coconut palm, Cocos nucifera.
IV. Zingiberales:-
8. Musaceae: Bananas, Musa spp.
9. Zingiberaceae: Gingers, Zingiber spp.
V. Poales:-
10. Bromeliaceae: Pineapple, Ananas comosus.
11. Poaceae.
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Some Eudicot Orders & Families
With some economic important examples:-
I. Caryophyllales:-
1. Amaranthaceae:- Beets, Beta vulgaris;
Spinach, Spinacea oleracea.
2. Caryophyllaceae:- Carnation, Dianthus.
II. Vitales:-
3. Vitaceae:- Grape vine, Vitis vinifera.
III. Myrtales:-
4. Lythraceae:- Pomegranate, Punica granatum.
5. Myrtaceae:- Eucalyptus, Eucalyptus spp.
Myrtle, Myrtus spp.
IV. Cucurbitales:-
6. Cucurbitaceae:- Squash, pumpkin, Cucurbita spp. ;
Melon, Cucumis melo;
Cucumber, Cucumis sativa;
Water melon, Citrullus lanatus.
V. Fabales:-
7. Fabaceae:- = Leguminosae.
VI. Fagales:-
8. Fagaceae:- Beech, Fagus;
Oak, Quercus spp.
Chestnut, Castanea.
9. Juglandaceae:- Walnut, Juglans spp.
VII. Rosales:-
10. Moraceae:- Mulberry, Morus spp.;
Fig, Ficus carica.
11. Rosaceae:-
VIII. Brassicales:-
12. Brassicaceae:- = Cruciferae.
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IX. Malvales:-
13. Malvaceae:- Mallows, Malva, Hibiscus;
Cotton, Gossypium spp.;
Cacao, Theobroma cacao;
Cola, Cola nitida;
Okra, Abelmoschus
X. Sapindales:-
14. Ancardiaceae:- Cashew, Anacardium;
Pistachio, Pistacia vera;
Terebinth, Pistacia spp.;
Sumacs, Rhus spp.
15. Rutaceae:- Oranges, Citrus spp. (lemons, grapefruit, etc.)
XI. Ericales:-
16. Theaceae:- Tea, Camellia sinensis.
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