The laboratory component of General Botany provides you the opportunity to view interrelationships between and among structures, to handle live or preserved material, to become familiar with the many terms we use throughout the course, and to learn how to use a microscope properly. Each of you will have your own microscope every week, no exceptions. This laboratory is fundamental, yet integral to your understanding of General Botany. The images in your manual are intended to serve as a guide while you view permanent or prepared slides. These must be viewed by each of you independently. At no time will questions be answered re where is a particular structure, etc. unless the slide is on the stage of your microscope and in focus. The content of the laboratory is rich, as is the terminology. You must come to lab prepared. You must come to lab knowing what the various terms you are about to deal with mean. There is no such thing as finishing early that simply isn't possible. In some laboratory exercises you will be asked to identify structures of an organism. For example, Examine slide 9 labeled Rhizopus sporangia w.m. and identify the mitosporangia, mitospores, columella, mitosporangiophore, and zygotes. In all likelihood you will only be able to see mitosporangia, mitospores, columella, and mitosporangiophores. If zygotes are absent in your slide you note that the population of hyphae you are examining are only reproducing asexually. These questions are written in this manner to further fortify your understanding of the organisms in question and not to trick you. Thinking about what you are viewing is not an option but a necessity! The phylogeny we have adopted in this course is a composite. No single phylogeny best reflects our collective understanding of all the organisms included in this course so we have created one that reflects modern thought and is based on both morphological and molecular data.

General Botany Laboratory Manual

By Jerry G. Chmielewski David Krayesky

AuthorHouse

Copyright © 2013 Jerry G. Chmielewski & David Krayesky
All right reserved.
ISBN: 978-1-4772-9653-0

Chapter One

Classification

We have historically classified objects because it adds order to our lives by facilitating access to these objects, by providing an understanding of them, or by allowing for the easy dissemination of information about them. Basic classification schemes we use today can be found on your hard drive, in the hardware store, the library, a lumberyard, auto wreckers, or your closet. Check out your wardrobe, socks in this drawer, underwear in another, and T-shirts in yet another. One of the major differences between the ways in which you or a respective business may classify their objects is that there is no right or wrong way to construct the groupings – whatever works best for you or the business is deemed acceptable.

Unfortunately the same does not hold true for the biologist. Faced with the daunting task of grouping and naming the world's nearly 2 million species, and in fact the real number may be 14-30 million species, the biologist must adhere to strict naming rules as defined by one of the following: International Code of Nomenclature for algae, fungi, and plants (ICN which replaced the International Code of Botanical Nomenclature – ICBN in July of 2011), the International Code of Nomenclature for Cultivated Plants (ICNCP); the International Code of Zoological Nomenclature (ICZN); International Code of Nomenclature of Bacteria (ICNB); International Committee on Taxonomy of Viruses (ICTV); and the International Code of Phyto socio logical Nomenclature (ICPN). The work must also be peer reviewed and published in a source acceptable to the scientific community before the newly created group has the potential for having scientific merit. Encompassed within these millions of organisms is a phenomenal amount of intra-group and inter-group variation.

Taxonomy (from the Greek taxis for arrangement and nomia for method) is that part of the biological sciences that deals with the identification, naming, and arrangement of organisms in a classification scheme. Written taxonomic history can be traced to Theophrastus of Eresos, the intellectual grandfather of modern botany who classified plants as herbs, shrubs, or trees as early as 300 BC. One of the defining periods in taxonomic history occurred during the 18th century and is specifically associated with the work of Carl von Linne (1707-1778), a Swedish botanist known more commonly as, Carolus Linnaeus (Latin was the language of choice among European scientists so writings and oftentimes names were Latinized) who championed the system of biological nomenclature in common use today. In truth, the binomial system of classification was first proposed by Gaspard (Casper) Bauhin (1560-1624).

Prior to Linnaeus' time there were no commonly accepted standards for naming. As such, organisms tended to have long, cumbersome, descriptive names. For example, botanists referred to the common wild briar rose as Rosa sylvestris alba cum rubore, folio glabro which from Latin roughly translates to pinkish white woodland rose with hairless leaves. The Linnaean system of classification brought order to a chaotic science and is founded on the use of binomial nomenclature wherein each of the basic units of classification is given two names (thus a binomial), a genus name and a species name, with the concurrent requirement that these form a pair and are stated together.

Linnaeus referred to the binomial as the nomen trivial (trivial name). Today, the binomial, or more specifically, the Latin binomial, constitutes what is referred to as the scientific or specific name. For example, Quercus alba is the white oak. Note that the scientific name is italicized and that the first part of the binomial, the genus name is capitalized, whereas the second part, referred to as the specific epithet or species is not capitalized. The genus name is a noun and singular and the species name is usually an adjective but may be a noun. Both are Latinized.

The Linnaean system of classification is viewed as being hierarchical in that each organism is placed within the lowest most group, the species, and closely related species occur in a larger group, the genus (plural genera). Related genera are grouped into a family, families into an order, orders into a class, classes into a phylum (formerly division in the botanical literature), and phyla (plural of phylum) into a Kingdom. Groups of all sizes, from species to Kingdom, are called taxa (singular taxon). The taxonomist is given the latitude to define groups how they choose and in doing so no set number of diagnostic characteristics, no special types of characters, and no special number of characters are involved in the designation of any group of organisms at a particular rank.

All classification schemes have a morphological bias out of necessity. It is possible that during the course of formulating groups that morphological, physiological, ecological, molecular, or chromosome data was used, though when it comes time to actually identify a specimen in hand in the laboratory or field only morphological data is readily available. Further, typically only those characteristics that can be identified with the naked eye or with the use of a hand lens are appropriate for inclusion in the character suite used to define the species. For this reason all classification schemes exhibit a morphological bias.

Although biologists have historically chosen to incorporate aspects of sexual reproductive biology in their definition of the species concept it is prudent not to do so because the strong majority of described species DO NOT undergo sexual reproduction. The best workable definition across all species boundaries, bacterial, viral, fungal, algal, plant, or animal is:

"a species is the smallest identifiable group of organisms that share more characteristics in common with each other than they do with any other group of organisms".

ALTERNATE LEAF ARRANGEMENT

ANDROECIUM

ANTHER SAC

CALYX

COMPOUND LEAF

COROLLA

DECUSSATE LEAF ARRANGEMENT

DICOT

DIOECIOUS

FERTILE SERIES

FILAMENT

FLORAL SERIES

GENUS

GYNOECIUM

INFLORESCENCE

LATIN BINOMIAL

LEAF BLADE

MONOCOT

MONOECIOUS

OPPOSITE LEAF ARRANGEMENT

OVARY

OVULES

PALMATE VENATION

PARALLEL VENATION

PEDICEL

PEDUNCLE

PERIANTH

PETAL

PETIOLE

PISTIL

RETICULATE VENATION

SEPAL

SIMPLE LEAF

SPECIES

SPECIFIC EPITHET

STAMEN

STERILE SERIES

STIGMA

STYLE

TEPAL

WHORLED LEAF ARRANGEMENT

Label the sepals, petals, stamens, filaments, anther sacs, pistil, stigma, style, ovary, and ovules. What type of placentation does this flower have? Is this flower actinomorphic or zygomorphic? Is this flower primitive or advanced? What about the following?

Taxonomy, What's in a Name?

Taxonomy, a term coined by the Swiss botanist Candolle (1813), initially referred to the endeavor of plant classification, that is, the use of morphological characters to order organisms into groups based on their similarities and differences. Today, taxonomy is a more generally used term applied to the act of classifying any group of organisms. Once organisms are placed into a group, that is classified, a taxonomist must apply a unique name to that group following a strict set of globally accepted rules. The...