226 



BUDS AND FLOWERS 



THE FRUIT 



diaphragm, notice should be taken also of the 

 pith, which is very variable in size. 



Young shoots of the grape offer a ready 

 means of distinguishing species and varieties 

 through their color and the amount and char- 

 acter of the pubescence. Shoots may be 

 glabrous, pubescent or hairy, and even spiny. 



The tendril is one of the organs most used 

 in determining species and varieties of grapes. 

 In some species, as V. Labrusca, there is a 

 tendril or an inflorescence opposite nearly 

 every leaf; these are continuous tendrils. All 

 other species have two leaves with a tendril 

 opposite each and a third leaf without a ten- 

 dril, called intermittent tendrils. To study 

 this organ it is necessary to have vigorous, 

 healthy, typical canes. Tendrils may be long 

 or short, stout or slender; simple, bifurcated, 

 or trifurcated; smooth, pubescent, or warty. 



Buds and flowers. 



The number of inflorescences borne by 

 species is an important character in some cases. 

 All species, excepting V. Labrusca, average 

 two inflorescences to a cane, but V. Labrusca 

 may bear from three to six inflorescences, each 

 in the place of a tendril opposite the leaf. 



Buds of different species of grapes vary 

 greatly in time of opening, as they do some- 

 what in varieties, so that the time the buds 

 begin to swell is a fine mark of distinction. 

 The angle at which the bud stands out from 

 the branch is of some value in determining 

 species. Differences in color, size, shape, posi- 

 tion, and amount of pubescence of buds must 

 all be noted in describing grapes. The scales 

 of the buds vary more or less in size and in 

 thickness. 



The time of bloom is an easy mark of dis- 

 tinction between several species of grapes, and 

 helps as well to distinguish varieties in a 

 species. Most species of grapes bear fertile 

 flowers on one vine and sterile flowers on an- 

 other, and are, therefore, polygamous-dioecious. 

 Sterile vines bear male flowers with abortive 

 pistils, so that, while they never produce fruits 

 themselves, they usually assist in fertilizing 

 others. Fertile flowers are capable of ripening 

 fruits without cross-pollination. Vines with 

 female flowers only are seldom found. In most 

 species of the grape, plants with sterile flowers 

 and those with complete flowers are found 

 mixed in the wild state, but usually only the 

 fertile plants have been selected for cultivation. 

 Plants raised from seeds of any of the species, 

 however, furnish many sterile vines. 



The degree of fertility of blossoms is also a 

 fine mark of distinction in species and varie- 

 ties of the grape. Fertile vines are of two 

 kinds in most species. The flowers on one 

 kind are perfect hermaphrodites, while in the 

 other kind the stamens are smaller and shorter 

 than the pistil, and eventually bent down and 

 curved under. These may be called imperfect 

 hermaphrodites, since they are seldom as fruit- 

 ful as the perfect hermaphrodites, unless fer- 

 tilized from another plant. On examination 

 with a microscope, it is found that self-sterile 



plants usually bear abortive pollen and that 

 the percentage of abortive pollen-grains varies 

 greatly in different varieties. The upright or 

 depressed stamen does not always indicate the 

 condition of the pollen, since there are many 

 instances in which upright stamens bear im- 

 potent pollen, and occasionally the depressed 

 stamens bear perfect pollen. 



Leaves. 



The size, shape, and color of the leaves are 

 quite distinctive of species and more or less 

 so of varieties, if allowances are made for 

 variation due to environment. The lobing of 

 leaves is a very uniform character in most 

 species, some having lobes and others having 

 entire leaves. The upper surface of the leaf 

 in some species is smooth, glossy, and shiny, 

 and in others is rough and dull. The lower 

 surface shows similar variations and has, be- 

 sides, varying amounts of pubescence, down, 

 and bloom. In some species the down re- 

 sembles cobwebs. The number, size, and shape 

 of the lobes are important in distinguishing 

 both varieties and species, as are also the 

 petiolar, basal, and lateral sinuses. As in most 

 plants, the margins of the leaves, whether ser- 

 rate, dentate, or crenate, are often distinguish- 

 ing characters. The petiole in different species 

 varies from short to long and from stout to 

 slender. Lastly, the time at which the leaves 

 fall is often a good distinguishing mark. 



The jruti. 



Of all organs, the fruit is most responsive to 

 changed conditions and hence most variable. 

 Yet the fruits furnish most valuable characters 

 for determining both species and varieties. 

 Size, shape, compactness, and number of, 

 clusters on a shoot must be noted. In the 

 berry, size, shape, color, bloom, adherence of 

 stigma to the apex, and adhesion of fruit to 

 the pedicel are all of value. Difference in 

 adherence of the skin to the pulp separates 

 European from all American grapes. The 

 color of the brush is often a certain distinguish- 

 ing character. The thickness, toughness, 

 flavor, and pigment of the skin have more or 

 less value. The color, firmness, juiciness, 

 aroma, and flavor of the flesh, as well as its ad- 

 herence to seed and skin, are valuable marks in 

 describing grapes. All species and varieties are 

 well distinguished by the time of ripening and 

 by the keeping quality. The color of the juice 

 is a plain and certain dividing line between 

 some species and many varieties. 



Seeds are accounted of much value in de- 

 termining species. The size and weight of 

 seed differ greatly in different species, as they 

 do also in varieties of any one species. Thus, 

 of native grapes, Labrusca has the largest and 

 heaviest seeds, and Vulpina has the smallest 

 seeds, while those of ^Estivalis are of medium 

 size and weight. The shape and color of seed 

 offer distinguishing marks, while the size, shape, 

 and position of the raphe and chalaza furnish 

 very certain marks of distinction in some 

 species. 



