Графични страници
PDF файл

At b, Fig. 114, is a representation of a flower of the Saxi. fraga, a very extensive genus; one species of which, an exotic, sometimes vulgarly called beef-steak, is much cultivated as a green house plant; it is very hardy; its leaves are roundish and hairy : it sends forth creeping shoots.

In shady woods, where the soil is loose and rich, we find in June and July, the winter-green (Gaultheria), a perennial plant which grows to the height of eight or ten inches; the pleasant taste of the leaves of this plant, and the still finer flavour of its fruit, are well known; the drooping blossom is also very delicate and beautiful, consisting of a bell-form corolla, (not unlike the lily of the valley,) the colour of which is white, tinged with pink. Though you may have often enjoyed eating the fruit and leaves of the winter-green, you will experience a delight which this mere pleasure of sense could not have afforded, when in your botanical rambles in the woods, you chance to meet with this plant in blossom, with its little flowers just peeping out from a bed of dry leaves : you may then enjoy the pleasure of a beautiful object of sight, with the higher en. joyment of intellectual gratification, by tracing in it, not only intrinsic beauty, but those characters which give it a definite place in scientific arrangement.

In the same natural family with the winter-green are two genera, Pyrola and Chimaphila, which by some botanists have been included under one ; but they appear to be sufficiently distinct from each other to constitute a separate genus. These plants belong to the natural order Bicornes, or two horns ; alluding to the two protuberances like straight horns, which appear on their anthers. The heath in the 8th class is of the same natural family, as also the whortleberry (Vaccinium), which contains a great many species ; the Europeans place this genus in the class Octandria, but an American botanist* says, “that of twenty-five species in our country, not one is found with eight stamens, and in Europe only three species are known with that number.” He very properly inquires, whether all our American species ought to be misplaced on account of those few European species. The cranberry (Oxy. coccus), which was formerly considered a species of the same genus as the whortleberry, as it has but eight stamens, is removed into the eighth class. Among the different species of the whortleberry is one with blue berries, another with very black berries, and the bilberry, which is a large shrub from five to eight feet high.

* Eaton.

Winter-green and other plants of the family Bicornes—Genus Vaccinium.

A great proportion of the plants in the first order of the tenth class are to be found in shady woods in June and July. We can here enumerate but few of them ; in the description of the genera of plants which we have provided, you will be able to find the most common ones.

We will not, however, omit to mention the Monotropa, a most curious little plant ; several stems of few inches in height, usually grow up in a cluster, each stem supporting a single flower, which, in form, resembles a tobacco pipe. The. stems have scales upon them but no leaves; the whole plant is perfectly white and looks as if made of wax; it is sometimes called Indian pipe. You must look for this in shady woods near the roots of old trees, in June or July.

Rhododendron, or as it is sometimes called, mountain laurel or rose bay, an evergreen with large and beautiful oval leaves, is found growing on the sides of mountains, or in wet swamps of cedar ; it flourishes beneath the shade of the trees; the pink and white flowers appear in large showy clusters and continue in bloom for a long period ; they have a 5 toothed calyx, a 5 cleft funnel-form, somewhat irregular corolla, stamens 10, sometimes half the number, capsule 5 celled, 5 valved.

At Fig. 114, c, is a flower of the genus Ledum, which is found in the same family as the Rhododendron; it has a very small calyx, and a flat, five-parted corolla.

Connected by natural relations to the two genera above men. tioned, is the American laurel (Kalmia), a splendid shrub, some. times found ten or thirteen feet high.' On the Catskill moun. tains, it is said to have been seen twenty feet in height; the flowers grow

in that kind of cluster called a corymb; they are either white or red; but this fair and beautiful shrub is of a poisonous nature, particularly fatal to sheep who are attracted towards it; one species of the Kalmta is on this account called sheep laurel.

Among the plants which have a place in this part of the artificial system, is the DIONÆA muscipula, or Venus' fly-trap. This is a native of North Carolina ; the leaves spring from the roots, each leaf has at its extremity a kind of appendage, like a small leaf doubled ; this is bordered on its edges by glands, resembling little hairs, containing a liquid that attracts insects; but no sooner does the unfortunate insect alight upon the leaf, than with a sudden spring, it closes itself, and the little prisoner is crushed to death in the midst of the sweets it had impru. dently attempted to seize ; after the insect, overcome by the

Monotropa or Indian pipe-Mountain laurel–Kalmia or sheep laurel Dionæa.

closeness of the grasp, has expired, the leaf again unfolds itself. These movements are accounted for, by attributing to the plant a power of irritability, which is excited by the touch of any object. Although we account for the phenomenon by attributing it to the irritability of the plant, we have only re. moved the difficulty by adducing a cause which itself remains to be explained. We shall in a future lecture make some remarks upon the irritability, or as it is sometimes called, sen. sibility of plants; many curious and interesting facts, respect. ing this singular property of vegetables, may be collected; many plausible theories to account for it have been given; but the efficient cause is too deep for man to penetrate ; his feeble faculties cannot comprehened the designs and opera. tions of Almighty Power.

The Second Order of the tenth class contains the Hydran. geu, an elegant East Indian exotic; a species of this plant, a shrub with white flowers, is said to have been found on the banks of the Schuylkill river.

The Pink (Dianthus) belongs to an extensive naturalorder, Caryophyllea, which is distinguished by having five petals in serted with claws. One native species of the

One native species of the genus Dianthus, , called armeria, or Wild Pink, has been found in New Jersey and New England.

The Third Order, or Trigynia, contains some plants which belong to the same natural order as the pink.

The Fourth Order, Tetragynia, is not important.

The Fifth Order, Pentagynia, produces a plant, Agrostemma, known by the name of Cockle; this is very common in fields; although troublesome, and regarded but as a weed, it is a handsome pink-like plant, bearing a deep red or purple blos. som; in its genuine character it differs little from the

genus which contains the pink, except in having five pistils instead of two, on which account it is placed in the fifth order.

Here is also found the Sorrel (Oxalis), which produces the oxalic acid, similar in its properties to the juice of lemons ; though poisonous, this acid is useful in taking the stains from linen.

In the Tenth Order is the Poke-weed (Phytolacca), a very common plant; the fruit of which consists of large, dark ber. ries, often used by children for the purpose of colouring purple. The young shoots are tender, and are sometimes eaten as a substitute for asparagus. The flower of this plant presents us with 10 stamens, 10 styles, a calyx with 5 white leaves resem. bling petals, a berry superior (above the germ), with 10 cells and 10 seeds.

Hydrangea-Pink-Cockle-Sorrel - Poke-weed.

We have now finished a review of the first ten classes, or the first group of classes, those which depend upon the single circumstance of the number of separate stamens ; in our next lecture we shall consider the two classes which depend on the number and insertion of the stamens.




Fig. 115.

In the class now before us, the num. ber of stamens is not the characteristic mark of distinction; this consists in the manner of the insertion of these or.

gans. In the analysis of the rose, b you have already become acquainted

with the leading features of this class, and will, therefore, the less need a minute detail of these elementary distinctions.

Had we followed the classification, which has, until recently, been admitted

by writers on botany,we should have had another class to examine before we came to Icosandria; this was called Dodecandria, from Dodeka, 12, and andria, stamen; it was not, as you might infer from the name, confined to 12 sta. mens, but contained from 10 to 20, without any regard to their insertion, as standing either upon the calyx or receptacle. This class produced confusion in the science of botany, for it is found that plants having more than ten stamens, frequently vary as to their number ; and there being no difficulty in dis. tributing all plants of this class into the two next, it has been by consent of most botanists left out of the classification; and the plants which it contained, arranged under Icosandria, if the stamens were on the calyx, and Polyandria, if the stamens were inserted upon the receptacle. The manner of insertion is always the same, and therefore there can be no confusion with respect to determining the classes upon this principle.

You will observe that this omission of one class changes the numbers of the remaining classes ; as Icosandria, which was formerly the twelfth, is now the eleventh, and so on with the other classes. It is on account of these changes that we wish

Class Icosandria-Omitted class-Names of classes expressive of their character.

you to learn the classes by their appropriate names, as Monandria, Diandria, rather than to confine yourselves merely to the numbers, as 1st, 2nd, &c. Besides, the name of each class is generally expressive of its character; and will, when you understand its derivation, convey to you the idea of this character, which, by the number alone, could not be done ; for example, the term eleventh class, conveys no distinction but that of mere number; but the classical name Icosandria (from Eikosi, 20, and andria, stamen), means 20 stamens ; this then reminds you of the circumstance on which the class is founded.

The name Icosandria, seems not, however, exactly well chosen to represent the eleventh class, which is not confined to twenty stamens, having sometimes as few as ten, and in some cases nearly a hundred stamens. An American botanist* has proposed to call the class Calycandria, from calyxt and an. dria, as the insertion of the stamens on the calyx is the essen. tial circumstance on which the class depends ; this change has been approved, but the old name is still used. Thus with respect to the name given to the great American Continent, all allow it should have been Columbia, after Columbus, its discoverer; but when once custom has sanctioned a name, it becomes very difficult to overcome this authority by arguments drawn from reason. We shall, therefore, in compliance with the use of botanists, call the class Icosandria.

Monogynia. The first genus which we meet with in this class is CACTUS; it contains many species ; a very splendid one is the Night. blooming Cereus (Cactus grandiflorus), having flowers nearly a foot in diameter, with the calyx yellow, and the petals white; they begin to open soon after the setting of the sun, and close before its rising, never again to blossom. Another species (speciossissimus), with flowers of the colour of crimson-velvet; it is said to be still more superb than the grandiflorus ; this genus belongs to a natural order, Succulentæ, or juicy plants ; they are in general destitute of leaves, but the stems often appear like a series of thick, fleshy leaves, one growing from the top of another. The different pecies of this genus are distinguished by a diversity of common names; when they are of a round form, they are called Melon thistles; when more cylindrical and erect, Torch thistles; when creeping with lateral roots, Cereuses ; and when composed of a stem resembling flattened leaves, Prickly pears.

* Darlington.

Calyz, genitive in Latin Calycis.

Calycandria-Genus Cactus-Different species distinguished by a diversity of common names.

« ПредишнаНапред »