538. =Varietal Names=, when any are required, are made on the plan of specific names, and follow these, with the prefix _var_. Ranunculus Flammula, var. _reptans_, the creeping variety: R. abortivus, var.

_micranthus_, the small-flowered variety of the species.

539. In recording the name of a plant it is usual to append the name, or an abbreviation of the name, of the botanist who first published it; and in a flora or other systematic work, this reference to the source of the name is completed by a further citation of the name of the book, the volume and page where it was first published. So "_Ranunculus acris_, L.," means that this b.u.t.tercup was first so named and described by Linnaeus; "_R. multifidus_, Pursh," that this species was so named and published by Pursh. The suffix is no part of the name, but is an abbreviated reference, to be added or omitted as convenience or definiteness may require. The authority for a generic name is similarly recorded. Thus, "_Ranunculus_, L.," means that the genus was so named by Linnaeus; "_Myosurus_, Dill.," that the Mouse-tail was established as a genus under this name by Dillenius; _Caulophyllum_, Michx., that the Blue Cohosh was published under this name by Michaux. The full reference in the last-named instance would be, "in Flora Boreali-Americana, first volume, 205th page,"--in the customary abbreviation, "Michx. Fl. i.

205."

540. =Names of Orders= are given in the plural number, and are commonly formed by prolonging the name of a genus of the group taken as a representative of it. For example, the order of which the b.u.t.tercup or Crowfoot genus, _Ranunculus_, is the representative, takes from it the name of _Ranunculaceae_; meaning _Plantae Ranunculaceae_ when written out in full, that is, Ranunculaceous Plants. Some old descriptive names of orders are kept up, such as _Cruciferae_ for the order to which Cress and Mustard belong, from the cruciform appearance of their expanded corolla, and _Umbelliferae_, from the flowers being in umbels.

541. =Names of Tribes=, also of suborders, subtribes, and the like, are plurals of the name of the typical genus, less prolonged, usually in _eae_, _ineae_, _ideae_, etc. Thus the proper b.u.t.tercup tribe is _Ranunculeae_, of the Clematis tribe, _Clematideae_. While the Rose family is _Rosaceae_, the special Rose tribe is _Roseae_.

542. =Names of Cla.s.ses, etc.= For these see the following synopsis of the actual cla.s.sification adopted, p. 183.

543. So a plant is named in two words, the generic and the specific names, to which may be added a third, that of the variety, upon occasion. The generic name is peculiar: obviously it must not be used twice over in botany. The specific name must not be used twice over in the same genus, but is free for any other genus. A _Quercus alba_, or White Oak, is no hindrance to _Betula alba_, or White Birch; and so of other names.

544. =Characters and Descriptions.= Plants are _characterized_ by a terse statement, in botanical terms, of their peculiarities or distinguishing marks. The character of the order should include nothing which is common to the whole cla.s.s it belongs to; that of the genus, nothing which is common to the order; that of the species nothing which is shared with all other species of the genus; and so of other divisions. _Descriptions_ may enter into complete details of the whole structure.

545. =Terminology=, also called _Glossology_, is nomenclature applied to organs or parts, and their forms or modifications. Each organ or special part has a substantive name of its own: shapes and other modifications of an organ or part are designated by adjective terms, or, when the forms are peculiar, substantive names are given to them. By the correct use of such botanical terms, and by proper subordination of the characters under the order, genus, species, etc., plants may be described and determined with much precision. The cla.s.sical language of botany is Latin. While modern languages have their own names and terms, these usually lack the precision of the Latin or Latinized botanical terminology. Fortunately, this Latinized terminology has been largely adopted and incorporated into the English technical language of botany, thus securing precision. And these terms are largely the basis of specific names of plants.

546. A glossary or vocabulary of the princ.i.p.al botanical terms used in phanerogamous and vascular cryptogamous botany is appended to this volume, to which the student may refer, as occasion arises.

-- 3. SYSTEM.

547. Two systems of cla.s.sification used to be recognized in botany,--the artificial and the natural; but only the latter is now thought to deserve the name of a system.

548. Artificial cla.s.sifications have for object merely the ascertaining of the name and place of a plant. They do not attempt to express relationships, but serve as a kind of dictionary. They distribute the genera and species according to some one peculiarity or set of peculiarities (just as a dictionary distributes words according to their first letters), disregarding all other considerations. At present an artificial cla.s.sification in botany is needed only as a key to the natural orders,--as an aid in referring an unknown plant to its proper family; and such keys are still very needful, at least for the beginner.

Formerly, when the orders themselves were not clearly made out, an artificial cla.s.sification was required to lead the student down to the genus. Two such cla.s.sifications were long in vogue: First, that of Tournefort, founded mainly on the leaves of the flower, the calyx and corolla: this was the prevalent system throughout the first half of the eighteenth century; but it has long since gone by. It was succeeded by the well-known

549. =Artificial System of Linnaeus=, which was founded on the stamens and pistils. It consists of twenty-four cla.s.ses, and of a variable number of orders; the cla.s.ses founded mainly on the number and disposition of the stamens; the orders partly upon the number of styles or stigmas, partly upon other considerations. Useful and popular as this system was down to a time within the memory of still surviving botanists, it is now completely obsolete. But the tradition of it survives in the names of its cla.s.ses, Monandria, Diandria, Triandria, etc., which are familiar in terminology in the adjective terms monandrous, diandrous, triandrous, etc. (284); also of the orders, Monogynia, Digynia, Trigynia, etc., preserved in the form of monogynous, digynous, trigynous, etc. (301); and in the name Cryptogamia, that of the 24th cla.s.s, which is continued for the lower series in the natural cla.s.sification.

550. =Natural System.= A genuine system of botany consists of the orders or families, duly arranged under their cla.s.ses, and having the tribes, the genera, and the species arranged in them according to their relationships. This, when properly carried out, is the _Natural System_; because it is intended to express, as well as possible, the various degrees of relationship among plants, as presented in nature; that is, to rank those species and those genera, etc., next to each other in the cla.s.sification which are really most alike in all respects, or, in other words, which are constructed most nearly on the same particular plan.

551. There can be only _one_ natural system of botany, if by this term is meant the plan according to which the vegetable creation was called into being, with all its grades and diversities among the species, as well of past as of the present time. But there may be many natural systems, if we mean the attempts of men to interpret and express that plan,--systems which will vary with advancing knowledge, and with the judgment and skill of different botanists. These must all be very imperfect, bear the impress of individual minds, and be shaped by the current philosophy of the age. But the endeavor always is to make the cla.s.sification answer to Nature, as far as any system can which has to be expressed in a definite and serial arrangement.

552. So, although the cla.s.ses, orders, genera, etc., are natural, or as natural as the systematist can make them, their grouping or order of arrangement in a book, must necessarily be in great measure artificial.

Indeed, it is quite impossible to arrange the orders, or even the few cla.s.ses, in a single series, and yet have each group stand next to its nearest relatives on both sides.

553. Especially it should be understood that, although phanerogamous plants are of higher grade than cryptogamous, and angiospermous or ordinary phanerogamous higher than the gymnospermous, yet there is no culmination in the vegetable kingdom, nor any highest or lowest order of phanerogamous plants.

554. The particular system most largely used at present in the cla.s.sification of the orders is essentially the following:--

SERIES I. PHANEROGAMIA: PHANEROGAMOUS OR FLOWERING PLANTS.

CLa.s.s I. DICOTYLEDONES ANGIOSPERMEae, called for shortness in English, DICOTYLEDONS or DICOTYLS. Ovules in a closed ovary.

Embryo dicotyledonous. Stem with exogenous plan of growth. Leaves reticulate-veined,

_Artificial Division I._ POLYPETALae, with petals mostly present and distinct. Orders about 80 in number, _Ranunculaceae_ to _Cornaceae_.

_Artificial Division II._ GAMOPETALae, with gamopetalous corolla.

Orders about 45, _Caprifoliaceae_ to _Plantaginaceae_.

_Artificial Division III._ APETALae or INCOMPLETae, with perianth, when present, of calyx only. Orders about 35 in number, from _Nyctaginaceae_ to _Salicaceae_.

CLa.s.s II. DICOTYLEDONES GYMNOSPERMEae, in English GYMNOSPERMS. No ovary or pericarp, but ovules and seeds naked, and no proper calyx nor corolla. Embryo dicotyledonous or polycotyledonous. Stem with exogenous plan of growth. Leaves mostly parallel-veined. Consists of order _Gnetaceae_, which strictly connects with Angiospermous Dicotyls, of _Coniferae_, and of _Cycadaceae_.

CLa.s.s III. MONOCOTYLEDONES, in English MONOCOTYLEDONS or MONOCOTYLS. Angiospermous. Embryo monocotyledonous. Stem with endogenous plan of growth. Leaves mostly parallel-veined.

_Division I._ PETALOIDEae. Perianth complete, having the equivalent of both calyx and corolla, and all the inner series corolline. About 18 orders.

_Division II._ CALYCINae. Perianth complete (in two series) but not corolline, mostly thickish or glumaceous. Chiefly two orders, _Juncaceae_, the true Rushes, and _Palmae_, Palms.

_Division III._ SPADICIFLORae or NUDIFLORae. Perianth none, or rudimentary and incomplete: inflorescence spadiceous. Of five orders, _Typhaceae_ and _Aroideae_ the princ.i.p.al.

_Division IV._ GLUMACEae. Perianth none, or very rudimentary: glumaceous bracts to the flowers. Orders mainly _Cyperaceae_ and _Gramineae_.

SERIES II. CRYPTOGAMIA: CRYPTOGAMOUS OR FLOWERLESS PLANTS.

CLa.s.s I. PTERIDOPHYTA, PTERIDOPHYTES (484).

CLa.s.s II. BRYOPHYTA, BRYOPHYTES (498).

CLa.s.s III. THALLOPHYTA, THALLOPHYTES (503).

SECTION XIX. BOTANICAL WORK.

555. Some hints and brief instructions for the collection, examination, and preservation of specimens are added. They are especially intended for the a.s.sistance of those who have not the advantage of a teacher.

They apply to phanerogamous plants and Ferns only, and to systematic botany.[1]

-- 1. COLLECTION, OR HERBORIZATION.

556. As much as possible, plants should be examined in the living state, or when freshly gathered. But dried specimens should be prepared for more leisurely examination and for comparison. To the working botanist good dried specimens are indispensable.

557. =Botanical Specimens=, to be complete, should have root or rootstock, stem, leaves, flowers, both open and in bud, and fruit.

Sometimes these may all be obtained at one gathering; more commonly two or three gatherings at different times are requisite, especially for trees and shrubs.

558. =In Herborizing=, a good knife and a narrow and strong trowel are needed; but a very strong knife will serve instead of a trowel or small pick for digging out bulbs, tubers, and the like. To carry the specimens, either the tin box (_vasculum_) or a portfolio, or both are required. The tin box is best for the collection of specimens to be used fresh, as in the cla.s.s-room; also for very thick or fleshy plants. The portfolio is indispensable for long expeditions, and is best for specimens which are to be preserved in the herbarium.

559. The _Vasculum_, or _Botanical Collecting-box_, is made of tin, in shape like a candle-box, only flatter, or the smaller sizes like an English sandwich-case; the lid opening for nearly the whole length of one side of the box. Any portable tin box of convenient size, and capable of holding specimens a foot or fifteen inches long, will answer the purpose. The box should shut close, so that the specimens may not wilt: then it will keep leafy branches and most flowers perfectly fresh for a day or two, especially if slightly moistened. They should not be wet.

560. _The Portfolio_ is best made of two pieces of solid binder's-board, covered with enamel cloth, which also forms the back, and fastened by straps and buckles. It may be from a foot to twenty inches long, from nine to eleven or twelve inches wide. It should contain a needful quant.i.ty of smooth but strong and pliable paper (thin so-called Manilla paper is best), either fastened at the back as in a book, or loose in folded sheets when not very many specimens are required. As soon as gathered, the specimens should be separately laid between the leaves or in the folded sheets, and kept under moderate pressure in the closed portfolio.

561. Of small herbs, especially annuals, the whole plant, root and all, should be taken for a specimen. Of larger ones branches will suffice, with some leaves from near the root. Enough of the root or subterranean part of the plant should be collected to show whether it is an annual, a biennial, or a perennial. Thick roots, bulbs, tubers, or branches of specimens intended to be pressed should be thinned with a knife, or cut into slices. Keep the specimens within the length of fifteen or sixteen inches, by folding, or when that cannot be done, by cutting into lengths.

562. =For Drying Specimens= a good supply of soft and unsized paper is wanted; and some convenient means of applying considerable pressure. To make good dried botanical specimens, dry them as rapidly as possible between many thicknesses of sun-dried paper to absorb their moisture, under as much pressure as can be given without crushing the more delicate parts. This pressure may be had by a botanical press, of which various forms have been contrived; or by weights placed upon a board,--from forty to eighty or a hundred pounds, according to the quant.i.ty of specimens drying at the time. For use while travelling, a good portable press may be made of thick binders' boards for the sides, and the pressure may be applied by strong straps with buckles. Still better, on some accounts, are portable presses made of wire network, which allow the dampness to escape by evaporation between the meshes.

For herborization in a small way, a light wire-press may be taken into the field and made to serve also as a portfolio.