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

Stamens united by 15. MON-ADELPHIA, their filaments in one

set or brotherhood, 16. DI-ADELPHIA, Two brotherhoods. Connexion.

The next class is named by prefixing syn, signifying together, to GENESIA, which signifies growing up.

Five united anthers, 17. SYN-GENESIA,

flowers compound. Fig. 9.

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The next class is named by an abbreviation of the word GYNIA, which signifies pistil, prefixed to ANDRIA, showing that the stamens and pistil are united. 18. GYN-ANDRIA,

Stamens growing out

of the pistil. The two following classes are named by

prefixing numerals to ECIA, which signifies a Position. house.

Stamens and Pistils 19. MON-CECIA,

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

What classes depend on the connexion of the stamens ?—Explain the signification of their names-What classes depend on the position of the stamens ?

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The name of the last class is a compound of two Greek words, CRYPTO and GAMIA, signifying a concealed union.

Stamens and Pistils Natural. 21. CRYPTO-GAMIA,

invisible, or too small to be seen with the

naked eye.

Fig. 11.

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Lichens. Mushrooms.

Ferns.

Mosses. The number of classes as arranged by Linnæus, was twenty

Two of them, Poly-delphia, (many brotherhoods,) which was the eighteenth class; and Poly-gamia, (many unions, the twenty-third class, have, by late botanists, been rejected as unnecessary

The eleventh class, Dodecandria, which included plants whose flowers contain from twelve to twenty stamens, has been more recently omitted. The plants which belong to these have been distributed among the other classes. A few botanists retain the whole twenty-four; among

Ame. rican writers who adopt but twenty-one, are Eaton, Torrey, and Nuttall.

THE ORDERS OF LINNÆUS. The orders of the first twelve classes are founded upon the number of PISTILS.

What does Gynandria signify ?-Monæcia ?-Diocia ?-Natural ClassClasses omitted--Orders of the first twelve classes, on what founded ?

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

ORDERS.
Names. No. of pistils.
1. Mono-GYNIA, 1.
2. DI-GYNIA, 2.
3. TRI-GYNIA, 3.
4. TETRA-GYNIA, 4.
5. PENTA-GYNIA,

5.
Orders found
in the first

6. HEXA-GYNIA, 6. this order seldom found. twelve classes. 7. HEPTA-GYNIA,

7. this still more unusual. 8. OCTO-GYNIA,

8. very rare. 9. ENNEA-GYNIA,

9. very rare. 10. DECA-GYNIA, 10.

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 GYMNO, signifying naked, and seeds usually four

SPERMIA, signifying seed, implying lying in the calyx.

that the seeds are not covered. 2. ANGIOSPERMIA. From ANGIO, signifying bag or sack, seeds numerous

added to SPERMIA, implying that the in a capsule.

seeds are covered. The orders of the 14th class, Tetradynamia, 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 contain

ing only pistils, which without stamens are superfluous. 3. FRUSTRANEA. Florets of the disk perfect, of the ray neu.

tral, or without the stamen or pistil ; therefore frustrated,

or useless. 4. NECESSARIA. Florets of the disk staminate, of the ray pis.

How are the orders named ?-Orders of the class Didynamia-Of Tetradynamia-Of the classes Monadelphia and Diadelphia—Of the class Syngenesia. .

tillate; the latter being necessary to the perfection of the

fruit. 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, Monæcia, and the 20th class, Diæcia, 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 barks of old

trees, old wood, &c. 6. FUNGI,—Mushrooms, mould, blight, &c.

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.

Having explained the principles on which the artificial classes and orders are founded, we will now place them before you, in a synoptical or general view. " SYNOPSIS OF THE CLASSES AND ORDERS OF LINNÆUS." CLASSES.

ORDERS. [ 1. MONANDRIA, 1 stamen. Number of styles ; if styles are 2. DIANDRIA, 2.

wanting, number of sessile stig3. TRIANDRIA, 3.

mas. Monogynia, 1 style or one 4. TETRANDRIA, 4. sessile stigma. Digynia, 2. TriNumber of 5. PENTANDRIA, 5. gynia, 3. Tetragynia, 4. PenStamens. 6. HEXANDRIA, 6. tagynia, 5. Hexagynia, 6. Hep

7. HEPTANDRIA, 7. tagynia, 7. Octogynia, 8. Enne8. OCTANDRIA, 8.

agynia, 9. Decagynia, 10. Poly-
9. ENNEANDRIA, 9. gynia, any number over 10.
10. DECANDRIA, 10.

Number and
Position.

11. ICOSANDRIA, over 10

stamens, on the calyx. 12. POLYANDRIA,many sta

mens, not on the calyx. 13. DIDYNAMIA, 4 stamens | 1. Gymnospermia, seeds naked.

2 of them longest. 2. Angiospermia, seeds in cap14. TETRADYNAMIA, 6 sta- sules. mens, 4 of them longest. / 1. Siliculosa, pod short.

2. Siliquosa, pod long.

Number and relative Length.

Of the classes Gynandria, Monæcia, and Diæcia–Of the class Cryptogamia -Synopsis of artificial classes and orders.

15. MONADELPHIA,

fila

Characters and names of prements united in 1 set. ceding classes. As, 1. Monandria, Connexion of 16. DIADELPHIA, filaments 2. Diandria, 3. Triandria, 4. Tethe Stamens united in 2 sets-papili- trandria, 5. Pentandria, 6. Hexanby filaments onaceous.

*dria. or anthers. 17. SYNGENESIA, anthers Disk and ray florets compared.

united--flowers com- 1. Æqualis, 2. Superflua, 3. Fruspound.

tranea, 4. Necessaria, 5. Segre

gata.
18. GYNANDRIA, stamens

on the pistil, distant
from corolla.

Characters and names of precePosition of 19. Monacia, stamens in ding classes, (as under the classes the Stamens flowers separate from 15 and 16,) 7. Heptandria, 8. Ocrelative to

pistils, on the same tandria, 9. Enneandria, 10. Decan. the Pistils. plant.

dria, 12. Polyandria, 16. Monadel. 20. Diecia, stamens in | phia.

flowers separate from

pistils on separate plants Invisible or 21. CRYPTOGAMIA,stamens

Natural families. 1. Filices, 2. Caducous.

invisible, wanting, or Musci, 3. Hepaticae, 4. Algæ, 5. very caducous.

Lichens, 6. Fungi.* We have now exhibited the Linnæan system; a thorough knowledge of it can be gained only by a series of inductions made by the analysis of single plants. You cannot be too much impressed with the idea, that a knowledge of nature can be acquired but by the observation of material objects.

LECTURE V.

[The beginner in Botany may omit the whole of the fifth Lecture, except the Directions for pronouncing the names of plants.”]

Condensed view of the Natural orders of Linnæus and Jussieu. After you have analyzed a number of plants, you will begin to observe a striking resemblance in many genera, and your own minds will suggest the propriety of arranging them into groups, without any reference to the

artificial class or order where they may have been placed. We thus form natural families. Among resemblances which give rise to natural families ; are,

1st, resemblance in seeds,
2d, in pericarps, or the envelopes of seeds,
3d, in stamens and pistils,
4th, in corollas and calyxes,
5th, in the modes of inflorescence, or the manner in which the

flowers grow together upon the stalks,
6th, in leaves,

7th, in roots and stems. In order to form a correct idea of the natural methods of classification, it is necessary to observe many plants, and the most constant characters of most of

* Eaton.

Synopsis of artificial classes and orders-What is necessary in order to gain a knowledge of nature ?-Arrangement of plants into natural familiesImpor. tant resemblances which give rise to natural families.

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