mens. LECTURE XXVI. CLASS PENTANDRIA-continued. Order Digynia. In this order of the fifth class is the family Gentiana, which affords some delicate flowers, as well as medicinal plants. The fringed gentian is a beautiful plant with a blue flower. This genus sometimes presents an irregularity in the number of staThe pigweed (Chenopodium), notwithstanding the low esteem in which it is usually held, you will see, is dignified with a long and high sounding name. Shakspeare says, "A rose, by any other name, would smell as sweet;" so, notwithstanding its great name, the pigweed is a very uninteresting plant; it is grouped by natural characters with the beet and dock, flowers which are destitute of beauty. The Umbellate plants which belong to the order and class we are now considering, have already been described under the 12th class of Jussieu's arrangement. Parsley, fennel, &c. belong to this natural family. The water cow-bane (CICUTA virosa), grows in ponds and marshes, and is a deadly poison. Cows are often killed in the spring by eating it; but as the summer advances, the smell becomes stronger, and they carefully avoid it. Linnæus relates, that in a tour made into Lapland for scientific purposes, he was told of a disease among the cattle of Torneo, which killed a great many of them in the spring, when they first began to feed in the pastures. The inhabitants were unable to account for this circumstance; but the Swedish botanist, examining the pastures, discovered a marsh where the CICUTA virosa grew in abundance; he aoquainted the people with the poisonous qualities of the plant, and thus enabled them to provide against the danger, by fencing in the marsh. Among the Umbellate plants is the Poison-Hemlock (CONIUn maculatum), which has a peculiarly unpleasant, nauseous smell; its stalk is large and spotted, from whence its specific name maculatum, which signifies spotted. This plant is supposed to be the poison so fatally administered by the Athenians, to Socrates and Phocion. Before we leave the Umbellate plants, as they are not so simple of analysis as many others, we will present you with a Gentiana-Pigweed-Umbellate plants-Water Cowbane-Poison Hem lock. drawing, which may assist you in understanding their general character. We have here a sketch of the Coriander : 1. CALYX (a), this is of that kind called an involucrum; the leaves which you see at the foot of the universal umbel, form what is called the general involucrum; the leaves, which are at the foot of the partial umbel, form a partial involucrum. Both of these involucrums are pinnatifid or have the leaves divided. 2. COROLLA (6), this is represented as magnified; you can see that it has five petals, inflected or bent inwards. 3. STAMENS, five, anthers somewhat divided. 4. PISTILS, two, reflected or bent back, as may be seen on the seed (c), where the stigmas are permanent. 5. PERICARP, is wanting, as in all umbellate plants. 6. SEED (c), is round, with its two styles at the summit. 7. STEM (d), is herbaceous, branched. 8. LEAVES (e), narrow, pinnatifid. 9. FLOWERS, terminal, umbelled.* The umbellate plants, although in some cases poisonous, supply us with valuable vegetables for food; as the parsnip, carrot, and celery. The roots and stalks of the Angelica, in Greenland, where they have but a scanty supply of food, are eaten and considered as a great delicacy. Dill, fennel, coriander and carraway, are used in confectionary, and are also made subservient to many valuable medicinal purposes. *The description of this plant is given on the authority of Nuttall, who calls it the American coriander, which he says is found in the neighbourhood of the Red River. The cultivated coriander has but a one leafed involucrum. Analysis of Coriander-Uses of the Umbellate plants. The milk-weed (asclepias) is by many writers placed here; but as its five stamens seem evidently situated upon the pistil, the genus is properly placed in the fifth order of the class Gynandria. Trigynia. This order contains the elder (Sambucus), a shrub, which, with its clusters of delicate white flowers, ornaments the fields during the summer. From the appearance of the blossom you might suppose it to be umbelliferous; the stalks do at first radiate from one common centre, but afterwards they are unequally subdivided; this arrangement of flowers is called a cyme. dark rich purple berries of the elder, and the peculiarity of its pithy stem, are among its distinguishing natural charac ters. The snow-ball (Viburnum); has a natural affinity with the elder: the flowers in its cymes are more thickly clustered together. Both are distinguished by their flat corollas; which are somewhat like a flat, round piece of paper, with five divisions notched on the border. The only generic difference between the snow-ball and the elder is, that the former has a berry, or pericarp, with one seed, the latter with three. Tetragynia. Here we find the grass of Parnassus (Parnassia). This is an interesting flower in its appearance; its leaves are white, and beautifully veined with yellow; the stem produces but one flower; the nectaries are remarkable for their beauty and singular appearance; they are five in number, heart-form, and hollow, surrounded with thirteen little threads, each one terminated with a round, glandular substance. The name is said, by an English Botanist,* to have arisen from the plant being a native of Mount Parnassus, in Greece, anciently considered as the dwelling of the muses. It is found in North America. Pentagynia. In the fifth order, we find the flax (Linum), so called from a Celtic word lin, a thread. The flax has a showy, blue flower, with an erect stem; a field of it in blossom presents a very beautiful appearance. The cultivated species is said to be an exotic, of Egyptian origin. It is from the liber, or inner bark of the stem of this plant, that all linen cloths, the finest lawn and cambric, are manufactured. We owe to it in one sense our literature; for the paper of which our books are made, is primarily derived from flax. The fibres of the stem * Thornton. Elder-Snow-ball-Grass of Parnassus-Flax. are not only thus important to the comfort of man, by contributing to his clothing, and to his intellectual improvement, in furnishing a method of disseminating knowledge, but the seeds are highly valuable for their oil, called lin-seed oil. This is used in medicine; and the delightful porformances of the artist are executed by means of colours, prepared with oil from the seed of the flax, laid upon the canvass made from the fibres of its stems. Polygynia. The thirteenth order occurs next to the fifth; there being no plants in the class Pentandria with six, seven, and eight pistils, &c. until we come to the yellow root (Zanthoriza), which is a native of the Southern States. It has 5 stamens, 13 pistils, no calyx, 5 petals, 5 nectaries, capsules 5 seeded; the flowers are purple, growing in panicles. It is a low shrub, with a yellow root, sometimes used by dyers. Our investigations into the class Pentandria have necessarily been somewhat tedious, on account of the number and importance of the plants which it contains. We do not, however, expect to make you practical botanists by introducing to your notice a few interesting plants; this can only be done by gathering flowers, and examining them according to those rules of analysis which we have endeavoured to explain in a simple manner. If you study flowers, you will read remarks upon them with pleasure and profit; if not, definitions or instruction will be read with little interest and little improvement. Sciences may be unfolded, every facility which books and teaching can give, may be placed before the youthful mind; but that mind must itself be active, or the seeds of knowledge will no more take root and expand, than the seeds of plants would vegetate if thrown upon the bare surface of a rock. LECTURE XXVII. CLASS VI.-HEXANDRIA, AND CLASS VII.-HEPTANDRIA. Or all the artificial classes, none presents us with so great a number of splendid genera as Hexandria; most of them are distinguished by bulbous roots, monocotyledonous seeds, and endogenous stems; the palms and some other plants of this class have fibrous roots in connection with the last two char Zanthoriza-Importance of the class Hexandria-Three important natural characters which distinguish many plants of this class. acters; these are inseparable; the nature of the stem, or the manner of its growth depending on the structure of the seed. The extensive family Liliaca, including the lily, tulip, Crown-imperial, &c. is one which presents itself first in considering this class. Fig. 110. You have already been made acquainted with the lily, as it was one of the first flowers you were taught to analyze; and, in a brief view of the liliaceous flowers, you have been presented with the most striking characters belonging to this family, which we might, following the example of great names, call "illustrious" race. an Pliny says, the "lily is next in nobility to the rose. Linnæus called the liliaceous flowers "Nobles of the vegetable kingdom;" he also called the palm trees "Princes of India.” In the class Hexandria, the symmetrical ratio between the number of stamens and the division of the other parts of the flower, is generally to be found. In the spiderswort, (Tradescantia), which has 6 stamens, we find the corolla 3 petalled, calyx 3 leaved, and capsules 3 celled. In the third class, which has 3 stamens, the divisions are often 6. In the lily, which has 6 stamens, there are 6 petals; 3 of these are exterior, 3 interior; the capsule is 3 sided, with 3 cells, and 3 valves; the seeds are arranged in 6 rows. This proportion of numbers seems to forbid the idea that this plant grew up without the agency of any designing mind. We are not always to expect the same symmetry in plants as has been here remarked. It is in the natural, as in the moral world, that, although every where around us, we see such proofs of order and system, as manifest the superintending care of one Almighty Being; yet there are irregularities which we can. not comprehend: but although we may admire the order, we are not to say that even what seems disorder is formed without a plan. *"Lilium nobilitate proximum est." A French poet, in the following lines, gives the lily a rank above the rose. "Noble fils du soleil, le lys majestueux, Il est roi des fleurs dont la rose est la reine." The white lily is here meant ; this is particularly admired by the French. Liliaceae-Symmetry of parts in the flowers of this class. |