Part 5

The literature of Botany can be traced back to a quite respectable antiquity, to the period of Aristotle (B.C. 384-322) who seems to have been the first to write of plants from the truly botanical point of view. Unfortunately, his special treatise on plants--θεωρία περὶ φυτῶν [Greek: theôria peri phytôn]--is lost; and although there are many botanical passages scattered throughout his other writings (which have been collected by Wimmer, Phytologiae Aristotelicae Fragmenta, 1836), yet none of them gives any indication of what his ideas of classification may have been. An echo of them is perhaps to be found in the works of his favourite pupil, Theophrastus Eresius (B.C. 371-286), who among all his fellows was the most successful in pursuing the botanical studies that they had begun under the guidance of the master. Theophrastus left behind him two important, though incomplete, treatises on plants, the oldest that have survived: the more familiar Latin titles of which are De Historia Plantarum and De Causis Plantarum. The latter is essentially physiological, touching upon agriculture to a certain extent: the former is mainly morphological, structural, descriptive, and it is here that the first attempt at a classification of plants is to be found. In writing the Historia, Theophrastus was endeavouring, as a Greek philosopher rather than as a botanist, to "give account of" plants; and in order to do so he found it necessary to arrange them in some kind of order. Seizing upon obvious external features, he distinguished (Lib. I. cap. 5) and defined Tree, Shrub, Undershrub and Herb, giving examples; adding, however, that the definitions are to be accepted and understood as typical and general, "for some may seem perhaps to deviate" from them. Simple as was this mode of arrangement, Theophrastus further simplified it in the course of his work, by treating trees and shrubs as one group, and undershrubs and herbs as the other.

_Quæ Morisone viro potuit contingere major Gloria, Pæonium quam superasse genus?

Ipse tibi palmam Phœbus concedit Apollo, Laureaque est capiti quælibit herba tuo._

Archibaldi Pitcairne M.D.]

It may seem, at first sight, singular that a lecture purporting to discuss the state of systematic botany in England during the 17th century should begin with a reference to the botany of the Greeks. The explanation is that the elementary classification introduced by Theophrastus persisted throughout the 17th century; the use of the groups Trees, Shrubs, and Herbs came to an end only in the 18th century, with the advent of Linnaeus. It seems almost incredible, but it is a fact, that the lapse of the nearly 2000 years that separated Theophrastus from Morison marked no material advance in the science of classification. Botanical works, when they were something more than commentaries on Theophrastus or Dioscorides, took cognizance of little else than the properties, medicinal or otherwise, of plants, and their economic uses.

A growing perception of the essential resemblances observable among plants can be traced, however, in the later Herbals, as they became less medical and economic and more definitely botanical. Thus, in the well-known work of Leonhard Fuchs (Fuchsius), De Historia Stirpium Commentarii, 1542, the plants are described in alphabetical order, without any reference to their mutual relation. But in Kyber's edition of Jerome Bock's (Tragus) De Stirpium Nomenclatura, etc., Commentariorum Libri Tres, published in 1552 (with a preface by Conrad Gesner), there is an attempt at a grouping of plants, though no principles are enunciated and no names are given to the groups, which resulted in the bringing together of labiate, leguminous, gramineous and umbelliferous herbs. The Cruydtboeck of Rembert Dodoens (Dodonaeus), 1554, marks much the same stage of progress, whereas the Nova Stirpium Adversaria of Pierre Pena and Matthias de l'Obel (Lobelius), issued in 1570, is a distinct step in advance. Here some idea is incidentally given of the principles that have been followed in the arrangement of the plants, but still no name is attached, as a rule, to the resulting groups. The work begins with an account of the herbaceous plants which, in modern terminology, are monocotyledonous: and at the end of the section (p. 65) de l'Obel thus explains what he has done:--"Hactenus comparendo quot potuimus plantarum genera, quarum effigies et naturae ordinis consequutione ita sibi mutuo haererent, ut et facillime noscerentur et memoriae mandarentur, a Gramineis, Segetibus, Harundinibus, ad Acoros, Irides, Cyperos, hincque Asphodelos bulborum tuniceorum Caepaceorumve naturam praetervecti sumus." Cruciferous, caryophyllaceous, labiate and umbelliferous herbs are also segregated to some extent in the course of the work: and the leguminous herbs are brought together into a definite group, "Alterum Frugum genus nempe graminis Trifolii et Leguminum," which is really the origin of the modern N. O. Leguminosae: though a few altogether foreign species, such as species of Oxalis, Anemone Hepatica, Jasminum fruticans L., and species of Thalictrum, are included among the trifoliate forms, and Dictamnus Fraxinella among the "Leguminosa." The Stirpium Historiae Pemptades Sex sive Libri XXX of Dodoens, published in 1583, shows considerable progress in classification as compared with his Cruydtboeck of 1554, more particularly in the recognition, apparently for the first time, of umbelliferous plants as a distinct group in a chapter headed De Umbelliferis Herbis.

Possibly these attempts to introduce some sort of system into Botany may have been inspired by the teachings of Conrad Gesner, that universal genius, who lived about this time (1516-1565). Though but fragments of his botanical writings have survived, it is clear from the much-quoted passage in a letter of his dated Nov. 26, 1565 (Epistolae Medicae, 1577, p. 113) that he too was seeking for the basis of a natural system of classification and that he thought he had found it in the flower and the fruit:--"Ex his enim notis (a fructu, semine and flore) potius quam foliis, stirpium naturae et cognationes apparent."

Evidently at this period classification was in the air, and at length it began to precipitate and to crystallise in the work of Andrea Cesalpino (Caesalpinus: 1519-1603), Professor in the University of Pisa, whose De Plantis Libri XVI, published in 1583, is one of the most important landmarks in the history of systematic Botany. Here for the first time a system is propounded which is based definitely upon morphological observation. Cesalpino turns to the "fructification," that is the flower and the fruit, for his distinguishing characters. "Enitamur igitur," he says (Lib. I. cap. xiv.), "ex propriis quae fructificationis gratia data sunt, plantarum genera investigare"; and he goes on to point out that the observable differences here depend on number, position and form of the parts:--"ad organorum constitutionem tria maxime faciant, scilicet, partium numerus, situs et figura." These principles he illustrates as follows:--the flower being the outermost covering of the fruit, a single flower may cover a single seed, as in the Almond: or a single seed-receptacle as in the Rose: or two seeds, as in the Umbelliferae: or two seed-receptacles, as in the Cress: or three seeds, as in the genus Tithymalus (Euphorbia); or three receptacles, as in the Bulbaceous plants (petaloid Monocotyledons): or four seeds, as in Marrubium: or four receptacles, as in Euonymus: or many seeds, as in the Cichoriaceae: or many receptacles, as in the Coniferae. The feature of the relative position of the parts which he especially emphasizes is whether the flower is inserted upon the top of the fruit (i.e. is epigynous): or is inserted lower around the fruit (hypogynous or perigynous). Moreover, the form of the seed, of the seed-receptacle, and of the flower, is to be taken into account.

The practical application of these principles led to a classification of plants which, though of course imperfect, was at least a good beginning. Following Theophrastus, Cesalpino divided plants into two main groups, (1) Trees and Shrubs, (2) Undershrubs and Herbs: each of these groups was then subdivided according to the nature of the fruit and of the flower. It will be observed that Cesalpino, as was customary at that time, designated as "seeds" all indehiscent one-seeded fruits, such as nuts and the varieties of achene. The following abstract will suffice to give an adequate idea of the results obtained. The author's own words are given as nearly as possible.

ARBOREAE: =Seminibus saepius solitariis=:

Glandiferae: e.g. Quercus. Vasculiferae: Fagus, Castanea. Nuciferae: Juglans, Carpinus, Corylus, Ulmus, Tilia, Acer, &c. Pericarpio tectae; flore in sede fructus: Prunus, &c. flore in apice fructus: Viburnum, Aesculus, &c.

=Seminibus pluribus=:

Flore carentes: Ficus. Flos in summo fructus: Morus, Sambucus, Hedera, Rosa, &c. Flos in sede fructus: Vitis, Arbutus, Cornus, &c. Sedes seminis multiplex tecta communi corpore: Pyrus, Citrus. " " in siliquam producta: leguminous plants. " " bipartita: Nerium, Syringa, Populus, Betula, Salix, &c. " " tripartita: Buxus, Myrtus. " " quadripartita: Vitex, Euonymus. " " tecta proprio corpore: coniferous plants.

HERBACEAE: =Solitariis Seminibus=:

Semina nuda, papposa: Valeriana. Semina pericarpio obducta: Daphne, Jasminum. Flos in summo fructus: Osyris, Valerianella. Flos in sede fructus, semen calyce exceptum: Urtica, Chenopodiaceae, Polygonaceae, Gramineae, Cyperaceae, Typhaceae.

=Solitariis Pericarpiis=:

Flos exterius situs (Pomum): Cucurbitaceae. Flos inferius situs (Bacca): Solanaceae, Ruscus, Arum, Actaea, &c.

=Solitariis Vasculis=:

Legumina: leguminous herbs. Capsulae: Caryophyllaceae, Primulaceae, Gentianaceae, &c.

=Binis Seminibus=: (Genus Ferulaceum) Umbelliferae.

=Binis Conceptaculis=:

Semina solitaria in singulis alveolis: Rubiaceae. " plura, flore continuo: Scrophulariaceae, &c. " " flore in foliola quaterna diviso: Cruciferae.

=Triplici Principio, non-Bulbosae=:

Semina nuda: Thalictrum. " solitaria in tribus alveolis: Euphorbiaceae. " plura in tribus alveolis: Convolvulaceae, Campanulaceae, &c.

=Triplici Principio, Bulbosae=:

Flos inferius sedet: bulbous Liliaceae. Flos in summo fructus: Amaryllidaceae. Bulbaceis ascribi desiderant: other Liliaceae, Iridaceae, Orchidaceae.

=Quaternis Seminibus=: Boraginaceae, Labiatae.

=Pluribus Seminibus in communi sede=: most Compositae.