LECTURE IV.

LATIN AND GREEK NUMERALS.-ARTIFICIAL CLASSES AND ORDERS.

We shall now present you with a list of Latin and Greek num als; these it is necessary to commit to memory, in order that y may understand the names given to the classes and orders. It is in Botany alone that a knowledge of these numerals will be usefu you; many words in our common language are compounded w them; as, uniform, from unus, one, and forma, form;-octagon, fr octo, eight, and gonia, an angle, hexagon, pentagon, &c.

In the first place, all plants are arranged in two grand division Phenogamous, when the stamens and pistils are visible, and Crypt gamous, when the stamens and pistils are too small to be visible, t the naked eye. The former division includes 20 classes, the latt

only the 21st.

The classes are founded upon distinctions observed in the ST MENS. All known plants are divided into twenty-one classes.

The first twelve classes are named by prefixing Greek numera to ANDRIA, which signifies stamen.

Words compounded with Latin and Greek numerals-Latin numerals-Greek nu merals Two grand divisions of plants-Classes, on what founded?—how many ?first twelve, how named?

The two following classes are named by prefixing Greek numerals to DYNAMIA, which signifies power or length.

The two following classes are named by prefixing Greek numerals to the word ADELPHIA, which signifies brotherhood.

Connexion of Stamens either by filaments or anthers.

15. MON-ADELPHIA,

16. DIA-DELPHIA,

{ Stamens united by their filaments

one or
Two brotherhoods.

The next class is named by prefixing SYN, signifying together, to GENESIA, which signifies growing up. Five united anthers, flowers compound.

17. SYN-GENESIA,

The next class is named by an abbreviation of the word GYNIA, which signifies pistil, prefixed to ANDRIA, showing that the stamens and pistils are united.

The two following classes are named by prefixPosition of Stamens ing numerals to ŒCIA, which signifies a house.

relative to the Pistil.

19. MON-ŒCIA,

Stamens and Pistils on separate corollas upon the same plant, or in one house.

20. DI-CCIA, Stamens and Pistils in separate corollas upon different plants, or in two houses.

* The name of this class does not now designate its character, since the number of stamens is often more or less than twenty.

Classes which depend on the number of stamens-those which depend on number and position-number and relative length-What classes depend on the connexion of the stamens?-Explain the signification of their names-What classes depend on the position of the stamens ?-What does Gynandria signify ?-Monoecia ?-Diccia?

The name of the 21st class is a compound of two Greek wor CRYPTO and GAMIA, signifying a concealed union.

Natural Families. {21. CRYPTO-GAMIA,

Stamens and Pistils invisible, or small to be seen with the naked ey

Fig. 11.

Lichens.

The number of classes as arranged by Linnæus, was twenty-fo (Two of them, Poly-adelphia, (many brotherhoods,) which was t eighteenth class; and Poly-gamia, (many unions,) the twenty-thi class, are now, by many botanists,* rejected as unnecessary. T eleventh class, Dodecandria, which included plants whose flowe contain from twelve to twenty stamens, has been more recen omitted. The plants which were included in these three classes ha been distributed among the other classes.

The Orders of Linnæus.

The orders of the first twelve classes are founded upon the nu ber of PISTILS.

The orders are named by prefixing Greek numerals to the wo GYNIA, signifying pistil.

Names.

ORDERS.

1. MONO-GYNIA,

No. of pistils.

1.

2. DI-GYNIA,

2.

3. TRI-GYNIA,

3.

4. TETRA-GYNIA,

4.

5.

Orders found in
the first twelve
classes.

5. PENTA-GYNIA,

6. HEXA-GYNIA,

7. HEPTA-GYNIA,

6. this order seldom found. 7. this still more unusual.

8. OCTO-GYNIA,

9. ENNEA-GYNIA,

10. DECA-GYNIA,

13. POLY-GYNIA, over ten pistils.

The classes vary as to the number of orders which they contain The orders of the 13th class, Didynamia, are but two.

1. GYMNOSPERMIA. From GYMNOs, signifying naked, and SPERMI Sends usually four, lying in signifying seed, implying that the seeds are n covered by a seed vessel.

the calyx.

2. ANGIOSPERMIA. Seeds numerous in a capsule.

From ANGIO, signifying bag or sack, added
SPERMIA, implying that the seeds are covered.

A few writers still retain the 24 classes of Linnæus ;-but in the works of Eato Torrey, Beck, and Nuttall, only 21 are adopted.

What does Cryptogamia signify?-Classes omitted-Orders of the first twel classes, on what founded?-How are the orders named ?-Orders of the class Did namia.

The orders of the 14th class, Tetrádynamia, are two, both distinguished by the form of the fruit.

1. SILICULOSA. Fruit, a silicula, or roundish pod.

2. SILIQUOSA. Fruit, a siliqua, or long pod.

The orders of the 15th class, Monadelphia, and of the 16th class, Diadelphia, are founded on the number of stamens, that is, on the characters of the first twelve classes, and they have the same names, as Monandria, &c.

The 17th class, Syngenesia, has its five orders distinguished by different circumstances of the florets, as:

1. EQUALIS. Stamens and pistils equal, or in proportion; that is, each floret has a stamen, a pistil, and one seed. Such florets are called perfect.

2. SUPERFLUA. Florets of the disk perfect, of the ray containing only pistils, which without stamens are superfluous.

3. FRUSTRANEA. Florets of the disk perfect, of the ray neutral, or without the stamen or pistil; therefore frustrated, or useless.

4. NECESSARIA. Florets of the disk staminate, of the ray pistillate ; latter being necessary to the perfection of the fruit.

the

5. SEGREGATA. Florets separated from each other by partial calyxes, or each floret having a perianth.

The orders of the 18th class, Gynandria, of the 19th class, Monocia, and the 20th class, Diœcia, like those of the 15th and 16th classes, depend on the number of stamens.

The orders of the 21st class, Cryptogamia, constitute six natural families.

1. FILICES,—includes all Ferns, having the fruit on the leaves. 2. Musci,-Mosses.

3. HEPATICAE,-Liverworts, or succulent mosses.

4. ALGAE,-Sea-weeds, and frog spittle.

5. LICHENES,-Lichens, found growing on the bark of old trees, old wood, &c.

6. FUNGI, Mushrooms, mould, blight, &c.

Note.-No confusion is produced in taking the character of some classes, for orders in other classes; for example: if you have a flower with ten stamens, united by their filaments into one set, you know by the definition of the classes that it belongs to the class Monadelphia; you can then, because it has ten stamens, place it in the order Decandria.

LECTURE V.

METHOD OF ANALYZING PLANTS BY A SERIES OF COMPARISONS-GENERAL REMARKS UPON PLANTS-METHOD OF PRESERVING PLANTS FOR AN HERBARIUM -POISONOUS PLANTS, AND THOSE WHICH ARE NOT POISONOUS.

THE dissection of a plant is, properly, analysis; the meaning of the term being a separation but when we speak of analyzing plants, we mean something more than examining each part of the flower; this is, indeed, the first step in the process; but by analysis, we learn the Class, Order, Genus, and Species of the plant. A person engaged in ascertaining the name of a plant, may be said to be upon a Botan

Of Tetradynamia-Of the classes Monadelphia and Diadelphia-Of the class Syngenesia Of the classes Gynandria, Monoecia, and Diœcia-Of the class Cryptogamia-Meaning of the word analysis-How used in Potany.

ical Journey, and the plant being his Directory; if he can read botanical characters impressed on it by the hand of Nature, he w by following system, soon arrive at his journey's end.*

Let us suppose, then, we have before us a plant in blossom, whose name and properties we are ignorant.-The name must first ascertained, and this can only be done with certainty by 1 Linnæan system.

In the first place we have two comparisons to make.

1st. Whether the Stamens and Pistils are VISIBLE.

2d. Whether they are INVISIBLE.

If the Stamens and Pistils are not visible, we have already arriv at the class, which is CRYPTOGAMIA.

If, however, the Stamens and Pistils are visible, we have now t comparisons to make.

1st. Whether the flowers have stamens and pistils on the same rolla.

2d. Whether the Stamens and Pistils are placed on different rollas.

If the Stamens and Pistils are on different flowers, we then sh find our plant either in the class Diæcia or Monacia; according the Stamens and Pistils are on different flowers, proceeding from t same root, or from different roots.

But if our plant has the Stamens and Pistils both enclosed in t same corolla, we must next examine,

1st. Whether the Anthers are separate, or,

2d. Whether the Anthers are united.

If we find five anthers united around the pistil, we have found t class of our plant; it is SYNGENESIA.

(If the Anthers are separate, we must proceed to a fourth stage, a

see,

1st. Whether the filaments are separate, or,

2d. Whether the filaments are united with each other, or,

3d. Whether the filaments are united to the pistil.\

If the latter circumstance is ascertained, we need search farther; our plant is in the class GYNANDRIA.

If the flower has not the filaments united to the pistil, we must a certain if the filaments are united with each other; if they are s and in two parcels or sets, the flower is in the class DIADELPHIA, bu If in one parcel or set, it is in the class MONADELPHIA. But if the filaments are separate, we must next examine,

1st. Whether these are similar in length, or,

2d. Whether they are of different lengths.

(Of different lengths, those only which have four or six stamens a to be regarded.)

If we find our flower has six stamens, four long and two short, v need go no farther, this is the class TETRADYNAMIA.

If the flower has four stamens, two long, and two short, it is in th class DYDYNAMIA.

If our flower comes under none of the foregoing heads, we mu then count the number of stamens; if these amount to more than te we must then consider their insertion, as,

* Thornton.

What two comparisons to be first made in analyzing a plant-When the stame and pistils are enclosed in the same corolla, what is next to be considered ?-Wh the anthers are separate, what must be done ?-If the filaments are separate, wh must be observed ?-If the flower has not stamens of unequal length, what is to observed ?