Shortly after and partly coincident with Engelmann, Munson, of Texas, made valuable contributions to our knowledge of American grapes. Munson is, what none of his predecessors had been, a cultivator of grapes and a breeder of new varieties as well as a botanical student of the subject. The region in which he lived was comparatively new to botanists, and it was partly, perhaps, on this account that he raised the number of species from the thirteen given by Engelmann to twenty-five. At the present time it appears doubtful if all of these will ultimately be given specific rank. Many of them undoubtedly will, and others of them will be recognized at least as varieties. Munson is regarded to-day as the chief authority on grapes of the semi-arid and mountainous districts of the West and is one of the leading authorities on American viticulture.

The last man who has paid special attention to the grapes of North America is Bailey, of Cornell. In his latest classification he gives twenty-three species of American grapes. Bailey is the only American botanist of experience and recognized standing in general botany who has paid special attention to the grape. His monograph of the genus Vitis which, with some changes, has appeared successively in Gray’s Synoptical Flora, The Evolution of Our Native Fruits, and the Cyclopedia of American Horticulture, is the most complete work we have on this subject. With his permission we have followed his arrangement of species in The Grapes of New York.

With this brief history of the formation of the genus Vitis as it now stands we pass to a consideration of the botanical characters of Vitis.

From the time when botanists first commenced to work on the grape there has been a constant search for taxonomic characters for separating the various species clearly and distinctly. Many of the earlier descriptions, while they are correct so far as they go, do not mention enough characters to enable one to distinguish between similar species. It has been found that dependence upon the shape of the leaf, size of berry, size of plant, date of ripening, and similar characters, is very uncertain and unsatisfactory and that, while these characters are always mentioned in descriptions as indicating the intrinsic value of a species, they are of little value from a systematic standpoint. There are, however, several characters of Vitis which have great taxonomic importance.

One of the fundamental characters which determine a species is continuous or intermittent tendrils, first noticed by Professor A. Braun[120] of Berlin. Vitis labrusca, the common Fox grape, is peculiar in that there are tendrils, or an inflorescence, opposite nearly every leaf; this arrangement is known as continuous tendrils. All other species have two leaves with a tendril opposite each and a third leaf without a tendril; such species are said to have intermittent tendrils. Continuity of tendrils is a variable character and to ascertain which of the two forms is present it is necessary to have vigorous, healthy, typical canes. The lowest leaves of canes usually have no opposite tendrils. This character is shown in the color-plates of the several species.

A closely related character is that of the number of inflorescences borne by a species. All species excepting Vitis labrusca average two inflorescences to the cane but the last named species, at least in some of its subdivisions, may bear from three to six inflorescences, each of course in the place of a tendril opposite a leaf.

Professor Millardet of Bordeaux first called attention to the value of that part of the cane known as the diaphragm as a means of distinguishing species. The cane of the grape vine contains a large pith, and in most species this pith is interrupted by woody tissue at the joints; this woody tissue is the diaphragm. The presence or absence of the diaphragm and its thickness are of taxonomic value. In Rotundifolia, the southern Fox grape, the diaphragm is absent; in Riparia, the Riverbank grape, it is very thin; in Rupestris it is slightly thicker; while Cordifolia, Aestivalis, and Labrusca have thick diaphragms. This character is studied best in the year-old canes of the grape. The color-plate of canes shows the range in thickness of diaphragms as they occur in several species.

V. rupestris V. riparia V. longii V. champini V. labrusca V. vinifera V. aestivalis bourquiniana V. aestivalis lincecumii V. bicolor V. aestivalis V. berlandieri V. rotundifolia V. doaniana V. labr. × V. vin. V. labr. x V. rip. SEEDS OF SPECIES OF VITIS [Natural Size and Enlarged
SEEDS OF SPECIES OF VITIS
[Natural Size and Enlarged]

The time of flowering is of considerable value in distinguishing species. Unfortunately it requires live plants and a certain time of year in order that this character be noted. The first American species to flower is Riparia. Rupestris flowers shortly after; next, Labrusca; Aestivalis a little later, although the Lincecumii variety of Aestivalis blooms slightly before Labrusca; Cordifolia is very late in coming into bloom, and Cinerea still later. Vinifera, the European grape, blooms shortly after Labrusca. The cultivated offspring of all wild grapes retain the blooming characters of the species from which they are derived.

Other characters that have been found of great value are those connected with the seed. The ability to use the seed characters, however, cannot readily be acquired except by the use of an illustrated manual and some experience in selecting the seeds, as they are quite variable on the same plant. The weight of the seeds differs in different species, but varies so much inside the species that it is not of much value from a systematic standpoint. In general, it may be said that the Labruscas have the largest and heaviest seed of our American grapes; Riparia has the smallest seed, with Aestivalis occupying an intermediate position. The size of the seeds in Aestivalis, however, is more noticeable on account of the small size of the fruit. The color-plate illustrates the different characters to be found in grape seeds and a study of this plate with the technical descriptions of the several species will show how important seeds become in classifying grapes.

Attention is called to the characters given by Bartram as distinguishing the European from the American species. The first difference that he mentions is in the shape of the fruit, that of the Vinifera being more or less oval and that of American species roundish or oblate. Recent technical descriptions of our American species give the fruit as spherical where the shape is mentioned at all. On the other hand it is known that most of the cultivated varieties of European grapes are oval. Does this mean that all of our cultivated American varieties which show oval berries, such as Isabella, Catawba, and others, contain Vinifera blood? It could not be said without careful study that this is true but it is certainly worthy of consideration. This point seems to have escaped the attention of our later-day botanists.

The sexual status of the grape has always been a source of misunderstanding. The earlier botanists spoke of American vines as dioecious, that is, bearing staminate and pistillate flowers on separate individuals. In this, as was noted on page 98, they were corrected by Bartram, in so far as American species were concerned, he stating that the vines of America were polygamous (showing staminate and hermaphrodite plants). Bartram did not presume to speak as to the sex of the flowers of the Old World grape. Later it was determined that the cultivated varieties of Europe were always hermaphrodite and that staminate forms were unknown. Engelmann[121] explains this so well and with such apparent satisfaction that we cannot do better than quote him here. “All the true Grape-vines bear fertile flowers on one stock and sterile flowers on another separate stock, and are therefore called polygamous, or, not quite correctly, dioecious. The sterile plants do bear male flowers with abortive pistils, so that while they never produce fruit themselves, they may assist in fertilizing the others; the fertile flowers, however, are hermaphrodites containing both organs—stamens and pistils—and are capable of ripening fruit without the assistance of the male plants. Real female flowers without any stamens do not seem ever to have been observed. Both forms, the male and the hermaphrodite, or if preferred those with sterile and those with complete flowers, are found mixed in their native localities of the wild plants, but of course only the fertile plants have been selected for cultivation, and thus it happens that to the cultivator only these are known; and as the Grape-vine of the Old World has been in cultivation for thousands of years, it has resulted that this hermaphrodite character of its flowers has been mistaken for a botanical peculiarity, by which it was to be distinguished, not only from our American Grape-vines, but also from the wild grapes of the old world. But plants raised from the seeds of this as well as any other true Grape-vine, generally furnish as many sterile as fertile specimens, while those propagated by layering or by cuttings, of course, only continue the individual character of the mother-plant or stock.” The accompanying plate shows various forms of grape flowers.

FLOWERS OF VITIS
FLOWERS OF VITIS

He further says in a foot-note: “These fertile plants, however, are of two kinds; some are perfect hermaphrodites, with long and straight stamens around the pistil, the others bear smaller stamens, shorter than the pistil which soon bend downward and curve under it; these may be called imperfect hermaphrodites, approaching females, and they do not seem to be as fruitful as the perfect hermaphrodites, unless otherwise fertilized.”

Beach[122] tested many of our cultivated varieties by sacking the clusters at blooming time and thus determined their capacity to fertilize themselves. From the data thus secured he divides them into four classes: 1st. Those that are able to fertilize themselves so that the clusters are perfect or varying from perfect to somewhat loose. 2d. Those in which the clusters are marketable, varying from moderately compact to loose. 3d. Clusters so loose as to be unmarketable. 4th. Those which are self-sterile or showing no fruit on covered clusters. Of 169 varieties tested, he found 38 belonging to the first class, 66 to the second class, 28 to the third, and 37 to the fourth.

Later it was found that the reason why certain varieties were self-sterile was on account of impotent and abortive pollen, the percentage of abortive pollen grains varying with different varieties and this percentage determining the degree of self-sterility. The upright or depressed stamen is not an invariable criterion of the condition of the pollen although it is usually. There are a few instances in which upright stamens bear impotent pollen but these are very exceptional. Munson made similar tests of vines of twenty-two[123] American species of vines secured from their habitats. In every case he found that they showed only two forms, the staminate vines and the self-sterile hermaphrodite, no perfect hermaphrodites being found. While of some of the species the number of vines tested was a half dozen or less, in most instances many vines were tested from different places. This is particularly interesting in that it becomes a puzzle as to where our perfectly hermaphrodite cultivated forms could have come from if such forms are not present in the wild vines of our woods and prairies.

The structure of the bark is an important distinguishing character for some species; in particular as to whether it peels off and whether in large flakes or in narrow strips or shreds. So, too, the color of the bark is often of taxonomic importance. The form and color of the leaves are often considered, but these characters are variable and may be misleading. The lobing of leaves is a fairly uniform character in most species, some having lobed and others having entire leaves. As to color and texture, the upper surface of the leaf in some species is smooth, glossy and shining and in others rough and dull with varying shades of green. The lower surfaces show similar variations with the addition of varying conditions of pubescence and down or even of cobwebs. In young seedlings the shape and surfaces of the leaves are apt to be quite different from those on the old plants, a character of systematic importance with some species. The flower, as compared with this organ in other genera, is of little importance in distinguishing the species of Vitis, there being an unusual similarity in the structure and appearance of the flowers of the several species.

The number of species of Vitis is very uncertain; as, indeed, is their habitat, except that they are generally confined to the temperate or subtropical regions. Some writers give the number as less than fifty but in all territories the number seems to depend on the thoroughness with which the region has been worked over botanically, and also on the judgment of the botanist doing the work. Gray recognized four species as being indigenous to America. Engelmann in his latest publication (Bushberg Catalogue, 1883), thirteen, while Munson gives twenty-five. Bailey in Gray’s Synoptical Flora, gives twenty-three species. Planchon (in 1887) gives twenty-eight species for the world. Seventeen of these are credited to America, ten to Asia, and one, the Vinifera, of unknown nativity. All of these lists, however, are known to be incomplete. Bessey[124] says that the grape is not native to the southern hemisphere, and Planchon credits none to any section south of the equator. Bailey credits two to Australia in a work not intended to cover more than those of American interest. And a correspondent[125] from that continent writes us giving a list of nineteen named and botanically described species indigenous to Australia. The number of species of grapes in the world depends upon the arbitrary limits set for a species and our knowledge of the genus is yet too meager to set these limits with certainty.

SPECIES OF AMERICAN GRAPES.
CONSPECTUS OF NORTH AMERICAN SPECIES OF VITIS.

SHOOT OF VITIS ROTUNDIFOLIA
SHOOT OF VITIS ROTUNDIFOLIA

1. VITIS ROTUNDIFOLIA Michx.[126]

Rotundifolia, or the southern Fox grape, seems to have attracted the attention of travelers in America from an early period. The references made in the journals of the explorers of colonial times can frequently be recognized as pertaining to this species. Rotundifolia seems to have escaped the attention of botanists, however, until the time of Michaux, who named and described it. Possibly the reason for its being overlooked was because of the supposition that this was the species Linnaeus had described under the name Vulpina.[127] The uncertainty as to who first described Rotundifolia created a confusion that was not definitely cleared up for nearly a hundred years and was responsible for the fact that half the botanists called it Vitis rotundifolia and a nearly equal number Vitis vulpina. Rafinesque, in 1830, described some three or four species within the bounds of what is now known as Vitis rotundifolia. None of these, however, has been accepted by later botanists.

The habitat of this species is southern Delaware, west through Tennessee, southern Illinois, southeastern Missouri, Arkansas (except the northwestern portions), to Grayson County, Texas, as a northern and western boundary, to the Atlantic Ocean and the Gulf on the east and south. It becomes rare as one approaches the western limit but is common in many sections of the great region outlined above, being most abundant on sandy, well-drained bottom lands and along river banks and in swamps, thick woodlands and thickets.

Vitis rotundifolia has for years been the favorite grape in many sections of the South. This is largely due, no doubt, to the fact that they have been usually compared with Labrusca or Labrusca-Vinifera varieties of northern origin which are not well adapted to southern conditions. With the introduction of native varieties of “bunch grapes”[128] of merit, the southern species may lose in popularity. It must be said, considering the fact that southern agricultural literature has been filled with recommendations of Rotundifolia grapes for nearly a century, that the cultivation of varieties of this species is comparatively limited.

The climate most suitable for Rotundifolia is that in which cotton grows and it thrives best in the lower portions of the cotton belt of the United States. On account of the late ripening of the fruit it requires a long season. Vines of Rotundifolia have been known to withstand a winter temperature as low as 12 degrees below zero, but under ordinary conditions this would undoubtedly be much too severe for most Rotundifolias. They do not suffer from the effects of hot summers but will not withstand drouth and are not well adapted to semi-arid conditions. All growers of varieties of this species agree that it does best on light sandy or alluvial soils; and while it may grow on rather heavy clays, if all other conditions are favorable, its vigor will be lessened.

The fruit of Rotundifolia is very characteristic. The skin is thick, has a leathery appearance, adheres strongly to the underlying flesh, and is marked with lenticel-like russet dots. The flesh is more or less tough but the toughness is not localized around the seed as in the case of Labrusca. The fruit and must of all the varieties of the species are characterized by a strong, musky aroma and are lacking in sugar and acid. Some varieties yield over four gallons of must per bushel. Wine-makers are divided in opinion as to its value for wine-making, but at present the most promising outlook for Rotundifolia varieties is as wine grapes. Rotundifolia does not produce fruit suitable for the table chiefly because the berries ripen unevenly and when ripe drop from the cluster. The common method of gathering the fruit of this species is to shake the vines at intervals so that the ripe berries will drop on sheets spread below the vines. The juice which exudes from the point where the stem is broken off causes the berries to become smeared and gives them an unattractive appearance. Owing, however, to the tough skin, the berries do not crack as badly as other grapes would under the same conditions but still they are not adapted to long distance shipments.

Under reasonably favorable conditions the vines attain great age and great size, and when grown on arbors, as they usually are, and without pruning, they cover a large area. The vines are planted from fifteen to forty feet apart in the vineyard, and the first year or two are trained to posts. Later the tops of these posts are connected by cross-bars and an arbor is thus formed. Pruning usually consists of removing dead wood but a few growers have always taken exception to the customary non-pruning method of treating the Rotundifolia. Lately Newman, of South Carolina, has published a bulletin[129] in which he recommends that the vines be pruned and raised on a trellis as is customary with other grapes. He gives figures to show that the damage to Rotundifolia vines is due to the bleeding that follows pruning and that this bleeding may be obviated by pruning in the fall or early winter. The success of such a practice would undoubtedly place the culture of Rotundifolia varieties on a better commercial footing.

Rotundifolia is remarkably resistant to the attacks of all insects and to fungal diseases. The phylloxera do not attack its roots and it is considered as resistant as any other, if not the most resistant of all American species. It is grown from cuttings only with difficulty. However, under favorable circumstances, and with skilful handling, this is a successful method of propagation. Under unfavorable circumstances, or where only a few vines are desired, it is better to depend on layers. As a stock upon which to graft other vines this species has not been a success. Wylie found great difficulty in crossing Rotundifolia with other species, and the crosses did not thrive under cultivation. Lately Munson has introduced several Rotundifolia hybrids.

2. VITIS MUNSONIANA Simpson.

Vine not very vigorous, a slender grower, usually running on the ground or over low bushes. Canes slightly angular; internodes short; tendrils intermittent, simple. Leaves smaller and thinner than Rotundifolia and rather more circular in outline; not lobed; teeth rather open and spreading; petiolar sinus V-shaped; both surfaces smooth, rather light green. Cluster with more berries but about the same size as Rotundifolia. Berry one-third to one-half the diameter, with thinner and more tender skin; black, shining; pulp less solid, more acid and without muskiness. Seeds about one-half the size of Rotundifolia, similar in other respects. Leafing, flowering, and ripening fruit very late.

In 1830 Rafinesque described, under the name Vitis peltata, or Vitis floridana, “a very singular species, lately found in Florida.” This description is brief and includes many characters of no taxonomic value. In 1885 or 1886, Mr. J.H. Simpson of Manatee, Florida, sent a specimen of a grape growing in his locality to Munson which was taken to be Rafinesque’s Vitis peltata. He consequently described it under the name Vitis floridana but the species was not generally accepted. Later Simpson gave it the name Vitis munsoniana.

Its habitat is central and southern Florida and the Florida Keys, and it is said to be the only grape growing on these Keys. It extends south of the habitat of Rotundifolia and blends into this species at their point of meeting.

Munsoniana appears to be a variation of Rotundifolia, fitted to subtropical conditions. It is tender, not enduring a lower temperature than zero. In the matter of multiplication it differs from Vitis rotundifolia in that it can be propagated readily from cuttings. Like Rotundifolia it is resistant to phylloxera. The species is of no value horticulturally.

3. VITIS RUPESTRIS Scheele.

Rupestris seems to have been first described and named by Scheele in 1848 in a contribution on the flora of Texas to the periodical Linnaea. Ravenel, in 1859, states that this grape is found in Texas and is there known as the Mountain grape. It was mentioned and described by Buckley, Engelmann, and all of the later botanists. (See Plate.)

This species is an inhabitant of southwestern Texas, extending eastward and northward into New Mexico, southern Missouri, Indiana and Tennessee to southern Pennsylvania and the District of Columbia. Its favorite places are gravelly banks and bars of mountain streams or the rocky beds of dry water-courses. Rupestris is usually considered drouth-resistant but Munson states that it is short-lived in the upland sandy soils in northern Texas, where, owing to long droughts, the land dries out deeply. Here, he says, it is not so successfully resistant to drouth as Lincecumii.[130]

This species is quite variable both in type and growth. It was introduced into France at about the same time as Riparia, and the French vineyardists selected the most vigorous and healthy forms for grafting stock. These pass under the various names of Rupestris Mission, Rupestris du Lot, Rupestris Ganzin, Rupestris Martin, Rupestris St. George, and others. In France they are stated to have given particularly good results on bare, rocky soils with hot, dry exposures. In California, Husmann[131] states, “It does not flourish in dry locations here, and as it suckers profusely and does not take the graft as readily as the two former classes [Riparia and Aestivalis], it is not largely propagated.” It has not been sufficiently cultivated in this country east of the Rocky Mountains so that it can be said what conditions of soil and climate best suit this species other than the general conclusions that may be drawn from the conditions present where the species is indigenous.

RUPESTRIS DU LOT
RUPESTRIS DU LOT

The clusters of fruit are small, with berries about the size of a currant and varying from sweet to sour. The berry is characterized by much pigment under the skin. The fruit has a sprightly taste wholly free from any disagreeable foxiness. According to Munson, it is too unproductive to be profitable. The sugar and acid content of the must is not known. Jaeger states that Rupestris wine sent to France was there judged as decidedly the best American claret yet tested.

Rupestris under cultivation is said to be very resistant to rot and mildew of the foliage. It is considered hardy by those familiar with it in the Southwest, and Campbell states that it withstood, without injury, 32 degrees below zero at Delaware, Ohio. The attention of hybridizers was attracted to this species over thirty years ago and various hybrids have been produced by Jaeger, Munson, Campbell and Millardet, all of whom considered Rupestris of great promise for grape-breeding. The root system of Rupestris is peculiar in that the roots penetrate at once deeply into the ground instead of extending laterally as in other species. Like those of Riparia, the roots are slender, hard, and resistant to the phylloxera. The species is easily propagated by cuttings. According to Husmann[132] the vines bench-graft readily but are difficult to handle in field grafting.

VITIS RUPESTRIS DISSECTA Eggert.

Vitis rupestris dissecta was named by H. Eggert of St. Louis, the name being placed on herbarium specimens but apparently not published by him. According to Bailey it differs from the typical forms of the species in having “more ovate leaves and very long teeth, and a strong tendency towards irregular lobing.” It is found in Missouri.

4. VITIS MONTICOLA Buckley.[133]

Vitis monticola was named and described by Buckley in 1861. There seems to have been some misunderstanding by later botanists as to exactly what Buckley’s species of this name is, and in spite of what has been written on the subject, it seems as though some of the botanists are still describing different species. The seed, in Engelmann’s figure, resembles that of the Rupestris very closely, while as figured by Viala the seeds resemble those of Cinerea or Cordifolia.

Monticola inhabits the limestone hills of central and southwestern Texas.

The fruit of this species has a very sweet and somewhat peculiar flavor. The vines can be propagated from cuttings only with difficulty. The species is adapted to a hot, dry climate and limestone land. It is found to be very resistant to phylloxera and is sometimes recommended as a stock for Vinifera but is not generally considered as valuable in this respect as Berlandieri. It is without value for its fruit and is of no horticultural importance to the eastern American grape-grower.

5. VITIS RIPARIA[134] Michx.