by Aristotle
2 · Let us now investigate what we have already mentioned, namely, desire in plants, their movement, and their soul and its function. A plant has not [25] respiration, although Anaxagoras declared that it has; and we even find many animals which have not respiration. We can see by ocular demonstration that plants do not sleep and wake, for waking is due to an effect of sensation, and sleeping is an [30] enfeebled condition of sensation, and nothing of this kind is found in that which vegetates at all times in the same condition, and is itself naturally without sensation. When an animal takes food, a vapour rises from the food into its head and it falls asleep, and, when the vapour which rises to its head is consumed, it wakes up. In [35] some animals this vapour is plentiful and yet they sleep but little. Sleep is the suppression of motion and this involves the quiescence of the thing moved.
The most important and appropriate subject of inquiry which arises in this [817a1] science is that proposed by Empedocles, namely, whether female and male sex is found in plants, or whether there is a combination of the two sexes. Now we assert4 that when the male generates it generates in another, and when the female generates it generates from another, and both are mutually separate. This is not [5] found to be the case in plants; for in a particular species the produce of the male plant will be rougher, harder, and stiffer, while the female will be weaker but more productive. We ought also to inquire whether the two kinds are found in combination [10] in plants as Empedocles states that they are. But my opinion is that this is not the case, for things which mingle together ought first to be simple and separate, and so the male will be separate and the female separate; they afterwards mingle, and [15] the mingling will only take place when it is produced by generation. A plant, therefore, would have been discovered before the mingling had taken place, and it ought therefore to be at the same time an active and a passive agent. The two sexes cannot be found combined in any plant; if this were so, a plant would be more [20] perfect than an animal, because it would not require anything outside itself in order to generate; whereas the plant does require the right season of the year and sunshine and its natural temperature more than anything. Thus it requires them at the time when the tree sprouts, and while the nutritive principle in plants is derived from the [25] earth, the principle which generates seeds is derived from the sun. Hence Anaxagoras said that the seeds of plants derive from the air, and others call5 the earth the mother and the sun the father of plants. But we must suppose that the mingling of the male and the female in plants takes place in some other way, because the seed of a plant resembles the embryo in animals, being a mixture of the male and female [30] elements. And just as in a single egg there exists the force to generate the chicken and the material of its nutriment up to the time when it reaches perfection and emerges from the egg, and the female lays the egg in a short space of time; so too [35] with the plant. And Empedocles is right when he said the tall trees do not bear their young; for that which is born can only be born from a portion of the seed, and the rest of the seed becomes at first the nutriment of the root; and the plant begins to move as soon as it is born. This, then, is the opinion which we ought to hold about [817b1] the mingling of the male and female in plants, similar to that which we hold about animals. This process is the cause of plants under a certain disposition of circumstances; for in the case of an animal when the sexes mingle the powers of the [5] sexes mingle after they have separated, and a single offspring is produced from them both. But this is not the case with plants. And if nature has mingled the male and the female together, she has followed the right course; and in plants the only [10] operation which we find is the generation of fruits; and an animal is only separated at the times when it is not having sexual intercourse, and this separation is due to its multifarious activities and intellectual pursuits.
But there are some who hold that the plant is complete and perfect because of [15] its possession of these two powers, and because of the food which is adapted to feeding it, and the length of its existence and duration. When it bears leaves and fruit its life will continue and its youth return to it. No excrement will be produced [20] from plants. A plant does not require sleep for many reasons, for it is placed and planted in the earth and attached to it and has no movement of itself; nor has it any definite bounds to its parts, nor does it possess sensation or voluntary motion, or a [25] perfect soul; indeed it has only part of a soul. Plants are only created for the sake of animals, and animals are not created for the sake of plants. Someone will urge that a plant requires food which is easily obtained and poor, yet it needs it very regularly and continuously, and without interruption. If it were agreed that a plant has an [30] advantage over an animal, it would follow that things which are inanimate were better and nobler than those which are animate; yet we see that the function of the animal is nobler and better than all those of the plant, and we find in the animal all the virtues which are present in the plant and many others. Empedocles said that [35] plants had their birth when the world was yet small and its perfection not attained, while animals were born after it was completed. But this account does not suit the facts, for the world is a whole, perpetual and eternal, and has never ceased to produce animals and plants and all their species. In every kind of plant there is [818a1] natural heat and moisture, and, when these are consumed, the plant will become weak and grow old and decay and dry up. Some people call this corruption, others do not.
3 · Some trees contain a gummy substance, such as resin and almond-gum [5] and myrrh, and frankincense, and gumarabic. Some trees have knots and veins and core and wood and bark and marrow within them; some trees consist almost wholly of bark. In some the fruit is underneath the bark, that is, between the bark and the wood. Some parts of the tree are simple, such as the moisture found in it and the [10] knots and veins; other parts are compounded from these, such as the branches and twigs and the like. These are not all found in all plants; for some have composite and some simple parts, while others do not have them. Plants possess various other parts as well—roots, twigs, leaves, branches, flowers, catkins, tendrils, and bark [15] surrounding the fruit.
Just as in the animal, so also in the plant there are homogeneous parts, and all the composite parts of a plant are like the members of an animal: the bark of a plant resembles the skin of an animal, while the root of a plant is like the mouth of an [20] animal, and its fibres are like an animal’s sinews, and so with its other parts. Any of these parts can be divided on one principle into similar parts, or a division can be made by dissimilar parts (just as mud can be divided in one way into earth only and in another into water; similarly the lungs and flesh can be divided up on one principle so that they are pieces of flesh, while on the other principle they can be [25] divided into their elements or radical parts). But a hand cannot be divided up into another hand, nor a root into another root, nor leaves into other leaves; but these roots and leaves are themselves the result of composition. Some fruits are composed [30] of few parts, some of many—olives, for example, which are made up of bark and flesh and a shell and a seed. Some fruits6 have as many as three coverings. All seeds have two barks. We have now mentioned the parts of which individual plants [35] consist. The aim of our discussion is to determine the parts of the plant and its coverings and its variations—this is very difficult—and in particular, to define its essential nature and its colour, and the period of its duration, and the effects which are produced upon it. Plants have not fixed habits of mind and the power of action [818b1] like that possessed by animals; and if we compare the parts of an animal with those of a plant, our discussion will be a long one, and we shall hardly avoid considerable differences of opinion in naming the parts of plants. For a part of a thing is of its [5] own kind and of its own particular substance, and, when it is once produced, each kind will remain in its original condition, unless it departs from it owing to some long continued infirmity. Flowers, fruits, and leaves will, in some cases, be produced [10] annually, in others they are not, nor do they remain as th
e bark does . . .7 This does not happen in plants; for various undetermined parts of plants are often shed (like [15] hair in the case of man and claws in the case of animals), and in their stead other parts grow either where the lost parts were, or elsewhere in some other place. It is clear from this that it is not determined whether the parts of a plant are really parts or not. It is wrong for us to say that those things with which an animal grows and by [20] which it reaches completion are not parts of it; but the leaves and everything that is found in a plant8 are parts of that plant, although they are not determined and are [25] gradually shed; for the antlers of a stag and the hair of certain animals, and the fur of certain of those which hibernate in hollows underground, fall off, and this process resembles the shedding of leaves.
We ought, therefore, to treat of the subjects which we mentioned first, and [30] begin to name the parts which are peculiar to certain plants and those which are common to all, and their differences. Let us say, therefore, that there is a great diversity in the parts of plants in respect of number and fewness, largeness and smallness, and in respect of strength and weakness. The reason of this is that the [35] moisture which is found in large trees, is in some trees, the fig, for example, like milk, in others it is like pitch, as in the pine, in others it is watery, like the liquid found in the vine, in others it is acrid, like that found in marjoram and in the herb called opigaidum. There are also plants which have their parts dry. Some plants have their parts well defined, and neither alike nor equal in size; others have parts which are similar to one another but not equal, in others they are equal but not [819a1] similar, and their position is not fixed. The differences of plants are recognized in their parts—differences in form and colour and sparseness and density and roughness and smoothness, and all their incidental differences in equality of size, [5] numerical increase and decrease, largeness and smallness. Some plants, too, will not be uniform, but will show great variation, as we have already said.
4 · Some plants produce their fruit above their leaves, others beneath; in [10] some plants the fruit is suspended from the stock of the tree, in others it grows from the root, as in the Egyptian trees which are called vargariaton; in some cases it grows in the middle of the plant. In some plants the leaves and knots are not separated; in others the leaves are equal in size and similar to one another, and some [15] of those which have branches have branches equal in size. The following parts, which we will name, are found in all plants, and admit of growth and addition— namely, the root, the shoots, the stem, and the branches; these resemble the limbs of animals which include all the other limbs. The root acts as an intermediary between [20] the plants and its food, and for that reason the Greeks call it the root and cause of life in plants, for it supplies the plant with the cause of life. The stem is the only part which grows out of the ground and forms and is like the stature of a tree. The [25] suckers are the parts which sprout from the root of a tree, while the branches are above the suckers. They are not found in all plants; and in some plants which have branches these are not permanent, but only last from year to year. There are plants which do not have branches or leaves, fungi, for example, and mushrooms. [30] Branches are only found on trees. Bark and wood and the pith of a tree are produced from moisture; some call this pith the womb of the tree, others the viscera, others the heart. The knots and veins and flesh of the whole plant are made up from the [35] four elements. Parts are often found which are adapted to reproduction, leaves, for example, and flowers and small twigs (which are flowers outside the plant); similarly with the fruit and leaves of a plant, and what is produced from the seed [40] and the shell which surrounds it.
Of plants some are trees, some are midway between trees and herbs and are called bushes, some are herbs, and some are vegetables. Almost every plant falls [819b1] under one of these names. A tree is a plant which has a stem growing from its root, from which stem numerous branches grow, olive-trees, for example, and fig-trees. A [5] plant which is something between a tree and a small herb, and is called a bush, has many branches growing out of its roots, like the thorntree and bramble. Vegetables are plants which have a number of stems growing out of one root and a number of [10] branches, rue, for example, and cabbage. Herbs are plants which have no stem, but their leaves grow out of their roots. Some plants are produced and dry up every year, wheat, for example, and vegetables. We can only indicate these various classes of plants by general inferences, and by giving examples and descriptions. Some plants [15] verge towards two extremes, mallow, for example (since it is both a herb and a vegetable), and likewise beet. Some plants grow at first in the form of low bushes and afterwards become trees, as, for instance, the nut-tree, the chaste-tree, and the [20] plant called ‘goatberry’. Perhaps myrtles, apple-trees, and pear-trees fall also under this class, for all of them have a number of superfluous stems growing from their roots. It is worth while to specify these that they may serve for purposes of example [25] and inference, but we must not investigate the definitions of every kind of plant.
Some plants are indoor plants, others garden plants, and others wild, in the same way as animals. I think, too, that all species of plants which are not cultivated become wild. Some plants produce fruit, others do not; some produce oil, others do [30] not; some have leaves and not others; some plants shed their leaves, others do not; some have branches, others do not. Plants differ greatly in their large or small size, [35] in beauty and ugliness, and in the excellence, or the contrary, of their fruits. Trees in a wild state bear more fruit than garden trees, but the fruit of the garden tree is better than that of the wild. Some plants grow in dry places, some in the sea, others [40] in rivers. Plants which grow in the Red Sea will there reach a great size, whereas they are only small in other places. Some plants grow on the banks of rivers, others in standing water. Of plants which grow in dry places, some grow on mountains, [820a1] others in the plain; some plants grow and flourish in the most arid districts, as, for example, in the land of the Ethiopians which is called Zara, and increase there better than anywhere else. Some plants live at high altitudes, some on moist ground, [5] others in dry, others equally well in either, as, for instance, willow and tamarisk. A plant changes very much with a difference of locality, and such variations must be taken into consideration. [10]
5 · A plant which is fixed in the ground does not like to be separated from it. Some places are better for certain plants than others; similarly some fruits are [15] better in one place than in another. In some plants the leaves are rough, in others smooth; in some they are small, in others they are cleft as in the vine. Some trees have a single bark, as the fig, others have several layers of bark, as in the case of the pine; some are bark throughout, as, for example, the mediannus. Some plants have [20] joints, reeds, for example; some have thorns, like the bramble. Some have no branches, others have a great number, like the sycamore. Other plants show various differences; for instance, suckers grow from some and not from others; this can only [25] be due to a difference in the root. Some plants have a single root only, the squill for example; for it grows in a single shoot and spreads by expansion underground, and will increase as it grows more and more and approaches the sunlight, because the sun draws out its shoots.
[30] Of the juices which are found in fruits, some are drinkable, as, for instance, the juice of grapes, pomegranates, mulberries, and myrtles. Some juices are oily, as in the olive and pine-nut; others are sweet like honey, as in the date and fig; others are [35] hot and pungent, as in marjoram and mustard; others bitter, as in wormwood and centaury. Some fruits are made up of a fleshy and a bony substance and a seed, plums for example; others, cucumbers for instance, are made up of a fleshy substance and seeds, others of moisture and seeds like the pomegranate. Some have rind outside and flesh inside, others flesh outside and seed inside; in others one [820b1] comes immediately upon the seed with the envelope which encloses it, as in dates and almonds; in others this is not so. Fruits are edible or inedible accidentally, and some people can
eat certain fruits while others cannot, and certain animals can eat [5] certain fruits while others cannot. Some fruits, again, are in pods, like seeds; others in sheaths, like9 weapons, wheat for example; others are enclosed in a fleshy [10] substance, dates for instance; others in husks, acorns for example, and some in several husks, a cuticle and a shell, nuts for example. Some fruits mature quickly, like mulberries and cherries, others slowly, as do all or most wild fruits. Some plants [15] produce their leaves and fruits quickly, others slowly—and of these some wait for the winter before coming to maturity. The colours of fruits and flowers vary very [20] much. One plant is green throughout, another has a tendency to blackness, another to whiteness, another to redness. Also the conformation of the fruit, if it be wild, varies considerably; for all fruits are not angular, nor do they take the form of [25] straight lines.