Botany

pericarp

(or wall) of the fruit may be divided into three layers: an external exocarp, a middle mesocarp, and an internal endocarp

Ecological species concept (The Species Concept)

A species is a group of related individuals that occupy a unique ecological niche.

Interbreeding species concept (The Species Concept)

A species is a population capable of interbreeding and is reproductively isolated from other groups.

Morphological species concept (The Species Concept)

A species is defined by morphology.

Cladistic species (The Species Concept)

A species is determined by phylogenetic history. Individuals with common evolutionary background considered to be a species.

species name

All living organisms given two-word Latin scientific name Only one correct scientific name for a species.

Hogg and Haeckel proposed a third kingdom in 1860's

All organisms that did not develop complex tissues were placed in Kingdom Protoctista

schizocarp (indehiscent)

At maturity, this kind of fruit breaks into single carpel segments called mericarps. Each mericarp can contain one to a few seeds, and the seeds remain completely surrounded by the pericarp. Members of the carrot family (Apiaceae) are characterized by this type of fruit. Another example is hollyhock. These fruits may be winged as in maples.

3 domains

Bacteria, Archaea, Eukarya

The International Code of Botanical Nomenclature

Book that standardizes rules governing the naming and classification of plants

What is a Fruit

Botanically, a fruit is a mature ovary together with any floral or vegetative structures that are attached to, become enlarged, and ripen with it.

Superior Ovary

Calyx and corolla attached to receptacle at base of ovary.

Cell Biology (Botanical Disciplines)

Cell structure and function

Pepos

Characteristic of this fruit type is the thick rind. Why is this fruit considered a special kind of berry? This type of fruit is restricted to the melon family (Cucurbitaceae).

Plant Taxonomy (Botanical Disciplines)

Describing, naming and classifying plants Plant Systematics Developing methods for classifying and naming plants

Beginning of 18th century

Details of fruit and flower structure, in addition to form and habit, used in classification schemes. Latin phrase name given to plants and animals. First word of phrase indicated genus (plural: genera).

13th century

Distinction made between monocots and dicots

Plumule

Embryo shoot

Carolus Linnaeus (1707-1778

Established Binomial System of Nomenclature Published Species Plantarum , 1753 Changed the Latin phrases to reflect relationships and placed one to many species in each genus Abbreviated names to two parts (binomials

Cladistic methods used

Examines natural relationships among organisms, based on shared features. Relationships portrayed on cladograms. The value or form of a feature referred to as a character state. Hypotheses made about which state is ancestral.

Theophrastus

First attempt to organize and classify plants in 4th century B.C. Classified nearly 500 plants by leaf characteristics

Cotyledons

Food storage organs that function as "seed leaves"

Plant Morphology (Botanical Disciplines)

Form and structure of plants

Group order

Genera grouped into families. Families grouped into orders. Orders grouped into classes. Classes grouped into phyla (divisions). Phyla grouped into kingdoms

Inflorescence

Group of flowers

Theory (fifth step)

Grouping of related principles

Epigeous germination

Hypocotyl lengthens, bends and becomes hook-shaped. Top of hook emerges from ground, pulling cotyledons above ground

Hypogeous germination

Hypocotyl remains short and cotyledons do not emerge above surface.

Copeland

In 1938 assigned single-celled, prokaryotic organisms to Kingdom Monera, leaving algae, fungi and single-celled eukaryotic organisms in Protoctista.

Whittaker

In 1969 developed five-kingdom system. Split Fungi from Kingdom Protista

Woese

In 1980s argued Monera should be split into Archaea and Bacteria, resulting in six kingdoms: Archaea, Bacteria, Protista, Fungi, Plantae, Animalia

samara (indehiscent)

In this type of fruit the pericarp around the seed extends out into a wing or membrane. What function does this serve? These fruits are produced in pairs in maples, while in ashes, elms, and birches they are produced singly. This kind of fruit can be considered a winged achene. Note: Fruits breaking into one-carpellate segments are called schizocarps (see above) and each of these segments is called a mericarp. In maples, a more precise term for the fruit is a samaroid schizocarp (and not, as I've seen written, a samurai schizocarp!)

grain

In this type of fruit, the seed coat and the pericarp are completely fused. Think of a corn kernel and how difficult it would be to separate the outer part of the kernel from the inner. This type of fruit is restricted to the grass family (Poaceae).

Endocarp

Inner boundary around seed(s)

Plant Ecology (Botanical Disciplines)

Interaction between plants and their environments

Plant Anatomy (Botanical Disciplines)

Internal structure of plants

Sepals

Outermost whorl

Petals

Next whorl inside sepals

Vivipary

No period of dormancy; embryo continues to grow while fruit is still on parent.

Occam's razor

One should not make more assumptions than the minimum needed to explain anything

Multiple

Pineapple and figs are derived from many individual flowers in single inflorescence. The individual ovaries of each flower along with accessory tissue (i.e., the inflorescence axis, sepals, and receptacle) develop into the fruit. On the pineapple identify the bracts and persistent sepals. The pineapple consists of a multiple of berries whereas the figs form a multiple of achenes (= syconium). Other examples of multiple fruits are mulberries (multiples of drupelets; left) and sweet gum (multiple of loculicidal capsules; right).

Plant Geography (Botanical Disciplines)

Plant distributions

Plant Physiology (Botanical Disciplines)

Plant function

Economic Botany and Ethnobotany (Botanical Disciplines)

Practical uses of plants and plant products Still vast amounts of botanical information yet to be discovered

Inferior Ovary

Receptacle grows up and around the ovary.

Data (third step)

Results from the experiment

Genetics (Botanical Disciplines)

Science of Heredity Potential development of better agricultural, medicinal, and other useful plants

Eclectic species concept (The Species Concept)

Single criterion not sufficient to identify species.

Exocarp

Skin

Nominalistic species concept (The Species Concept)

Species do not exist.

What is a seed?

Specifically, it is a ripened (or fertilized) ovule containing an embryo within a seed coat, and often, additional storage tissues.

Epicotyl

Stem above cotyledon attachment

Hypocotyl

Stem below cotyledon attachment

Receptacle

Swollen end of peduncle or pedicel

Hypothesis (first step)

Tentative, unproven explanation of an observation

Experiment (second step)

Test to determine if a hypothesis is correct Must be repeatable Variables - Aspects of the experiment that can be changed or held constant Good experiments consist of two parts: Variable changed Variable held constant = Control

achene (indehiscent)

The single seed of this fruit is attached to its surrounding pericarp only at its base. Thus, the pericarp is relatively easily separated from the seed. The fruit is dry and indehiscent. These fruits are also extremely variable in form. They are derived from either an ovary consisting of a single carpel or one containing two to several fused carpels. Crack open a sunflower seed. Are you actually cracking open the seed or the pericarp? Is the seed fused to the ovary (i.e., fruit) wall? Other examples include buttercups and buckwheat.

head(capitulum)

a compact inflorescence composed of a very short axis and usually sessile flowers.

Pomes

a simple fleshy fruit whose flesh is derived primarily from the receptacle

nut (indehiscent)

These are one-seeded fruits similar to achenes, but they are generally larger, and the pericarp (actually, exocarp) is much harder and thicker. They are derived from an ovary consisting of fused carpels, but are one-seeded by the abortion of ovules. They also mature with a cup or cluster of bracts at their base. Other examples

siliques

These fruits split along two sides or seams, but the seeds are borne on a central partition (= replum), which is exposed when the halves of the fruit separate. These fruits are characteristic of the mustard family (Brassicaceae). Also long and tubular.

silicles

These fruits split along two sides or seams, but the seeds are borne on a central partition (= replum), which is exposed when the halves of the fruit separate. These fruits are characteristic of the mustard family (Brassicaceae). Has a somewhat cylindrical shape.

hesperidum

This fruit is also a type of berry with a leathery skin containing numerous oil glands. Numerous outgrowths from the inner lining of the ovary wall become saclike and swollen with water as the fruit develops. Most members of the citrus family (Rutaceae) produce this kind of fruit. Have you ever eaten a kumquat?

folicles (dehiscent)

This fruit splits along one side or seam only, exposing the seeds within. Other examples include larkspur, peonies, and columbines. This type of fruit is derived from an ovary consisting of a single carpel.

legume

This fruit splits along two sides or seams. Literally thousands of members of the pea family (Fabaceae) produce this type of fruit. Peanuts are also legumes, but they are ATYPICAL in that the fruits develop and mature underground; the seeds usually released in nature by bacterial breakdown of the pericarp instead of through an active splitting action. Observe the samples of legumes on display. Legumes differ from follicles not only in the splitting of two seams rather than one, but also by having ovaries containing two fused carpels rather than a single carpel.

aggregate

This kind of fruit is one that is derived from single flower with several to many pistils. The individual pistils each develop into tiny drupes or other fruitlets, but they mature as a clustered unit on a single receptacle.

Berries (fleshy fruit types)

This kind of fruit usually develops from an ovary consisting of two or more fused carpels and commonly contains more than one seed. The entire pericarp is fleshy and relatively soft at maturity, and is difficult to distinguish between mesocarp and endocarp. Although many of these fruits contain more than one seed, notable exceptions are dates and avocados, which have only one. These fruits are derived from either superior or inferior ovaries.

capsules (dehiscent)

This type of fruit is the most common of the dried fruits that dehisce. They are derived from an ovary containing two to many fused carpels, and are typically several- to many-seeded. Some fruit dehisce along the partitions between the carpels, while others dehisce through the cavities (locules). Still others form a cap towards one end that pops off and permits the release of seeds, or they form a row of pores through which the seeds are shaken out as the fruit rattles in the wind. Other examples are yucca (upper left), jimsonweed, witch-hazel, violets, Dutchman's pipe (upper center), poppies (upper right), corn cockle (bottom left), and purslane (bottom right

Drupe (fleshy fruit types)

This type of fruit usually develops from flowers with a superior ovary containing a single ovule. Locate the cut peach, plum, or cherry on display and identify the exocarp, mesocarp, stony endocarp ("the pit"), and seed. The mesocarp is not always obviously fleshy. In coconuts, for example, the husk (consisting of the mesocarp and exocarp), which is usually removed before the rest of the fruit is in markets, is very fibrous. What purpose do you think this fibrous husk might serve? The seed ("meat") of the coconut is hollow and contains a watery endosperm referred to as "milk". The endosperm is surrounded by the thick, hard endocarp typical of drupes.

Radicle

Tip of embryo that develops into root

Mesocarp

Tissue between exocarp and endocarp

Principal (fourth step)

Useful generalization derived from experimental data

dichasium

a three-flowered cluster composed of a peduncle bearing a terminal bearing a terminal flower and, below it, two bracts with each bract subtending a lateral flower.

catkin

an inflorescence consisting of a dense spike or raceme of apetalous, unisexual flowers, as seen in the willow, beech, and birch families (Salicaceae, Fagaceae, and Betulaceae, respectively).

determinate

an inflorescence in which the terminal or central flower opens first, resulting the cessation of the primary axis elongation.

Stamens

attached around base of pistil

Pistil

consists of stigma, style, and ovary

Embryo

cotyledons and plantlet

Angiosperms

flowering plants

umbel

several branches radiating from the same point and are terminated by single flowers or secondary umbels (i.e., simple versus compound umbels).

corymb

short, broad and relatively flat-topped.

panicle

similar to a raceme but greatly branched.

raceme

stalked flowers arranged along an elongate central axis.

indehiscent

the pericarp encloses the seed so that the entire fruit is the dispersal unit.

dehiscent

the pericarp splits open to release the seeds so that the seed is the unit of dispersal

spike

un-stalked (= sessile) flowers arranged along an elongate central axis.