Слике страница
PDF
ePub
[graphic]

7. Heptandria, seven stamens.
8. Octandria, eight stamens.

9. Enneandria, uine stamens.

10. Decandria, ten stamens, filaments separate.

11. Dedceandria, twelve stamens to nineteen, inserted on the receptacle.

12. Icosandria, twenty or more stamens, inserted upon the calyx or corolla.

13. Polyandria, many stamens.

14. Didynamia, four stamens, two long, two short.

15. Tetradynamia, six stamens, four long, two short.

16. Monadelphia, filaments united at bottom, but separate at top.

17. Diadelphia, filaments united in two

sets.

18. Polyadelphia, filaments united in three

or more sets.

19. Syngenesia, filaments united, and five

stamens.

20. Gynandria, stamens inserted on the pis til, or on a pillar elevating the pistil.

21. Monecia, stamens and pistils in separate corollas, upon the same plant.

22. Diccia, stamens and pistils in distinct corollas, upon different plants.

23. Polygamia, various situations; stamens only, or pistils only.

24. Cryptogamia, stamens and pistils inconspicuous.

Obs. I have introduced beneath, a representation of the pistils and stamens of a few of the first classes; and the pupil will, doubtless, be led to observe them within any flowers which fall in his way in his walks or other ise.

[blocks in formation]

411. The Triandria contains chiefly the natural tribe of grasses; the hexandria, the lilies. The Icosandria contains the edible fruits; the polyandria, has many poisonous plants.

The Tetradynamià contains the natural tribe of flowers, which are antiscorbutic.

The Monadelphia is composed chiefly of the mallow tribe.

Diadelphia consists of the pea tribe, which produces edible seeds.

Syngenesia possesses the compound flowers And the cryptogamia contains the natural tribes of ferns, mosses, sea-weeds, and mush

rooms.

Obs-The first order of the fourteenth clay, denominated "didynamia gymnospermia," are all innocent or wholesome: those of the other order, are fetid, narcotie, and dangerous; being allied to a large part of the pratan Iria monogynia, known to be poisonous, as containing henbane, night-shade, and tobacco. The whole class tetradynamia is wholesome, Whenever the stamens are found to grow out of the calyx, they indicate the pulpy fruits of such plants to be wholesome. The papi

Honaceous plants are wholesome, except the seeds of the laburnum ; which, if eaten unripe, are violently emetic and dangerous, Milky plants are generally to be suspected. Umbelliferous plants, which grow in dry or elevated situations, are aromatic, safe, and often whole some; while those that inhabit low and watery places, are among the most deadly poisons.

442. Other distinctions in each class produce a division of the classes, called Orders. A further division of the orders, founded on distinctions in the nectarium, lead to the Genera. Other divisions of the genera,, in regard to the root, trunk, leaves, &c. lead to Species; and casual_differences in species are called Varieties.!

443. The natural substances found in all vegetables are, sugar in the sugar-cane, beet, carrots, &c.; gum, or mucilage, which oozes from many trees; jelly, procured from many fruits; turpentine and tar from the pine; bitters, from hops and quassia; and the narcotic principle from the milk of poppies, lettuce, &c.

444. The vegetables of the greatest value to man, are those which produce gluten or starch; as wheat, potatoes, barley, beans, &c. Oils are produced by pressing the seeds or kernels o. vegetables; as olives, almonds, linseed, &c. Volatile oils are distilled from peppermint, lavender, &c. Wax is collected from all flowers by bees.

445. Resins exude like gum from firs and other trees; and are known as balsams, varnishes, turpentine, tar, pitch, &c. Of this class,

[ocr errors][merged small]

too, is Indian rubber; which is a gum that exudes from a certain tree in South America.

Iron also mixes with the substance of most vegetables; and is the cause of the beautiful colours of flowers. Pot-ash is obtained from the ashes of burnt vegetables; as kelp, vine, fern, &c..

Obs. The classes monœcia and dioecia, which have the pistil and stamens in different flowers, and on different plants, have the pistil fructified by the bees and other insects, which enter the corolla to extract the honey from the nectarium. The pollen in those flowers which have stamens only, falls on their bodies, and is carried by them to the flowers which have pistils only. And it deserves to be noticed, as a proof of the contrivance of the Divine Architect of Nature, that when the pistil is shorter than the stamens, the flowers grow upright, that the pollen may fall from the anthers of the stamens or the stigma of the pistils; but when the pistil is longer than the stamen, the flower hangs downward, that the pollen, in falling, may be caught by the stigma of the pistil.

Who can paint

Like Nature? Can imagination boast,
Amidst his gay creation, hues like hers?
And can he mix them with that matchless ekin,
And lay them on so delicately fine,

And lose them in each other as appears
in every hud that blows? If fancy, then,
Unequal fails beneath the pleasing task,
Ah! What shall language do?

THOMSON.

[ocr errors]
« ПретходнаНастави »