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4. PYRUS SEROTINA Rehder

1. Rehder Proc. Amer. Acad. Arts & Sci. 50:213. 1915.

Tree vigorous, upright, attaining a height of 20 to 50 ft., the branches becoming glabrous. Leaves ovate-oblong, sometimes ovate, 3 to 5 in. long, rounded at the base and rarely subcordate or cuneate, long-acuminate, sharply setose-serrate, with partially appressed seratures; when young, villous, or lower surface cobwebby, but becoming glabrous. Flowers white, borne in 6 to 9 flowered umbellate-racemose clusters; glabrous or somewhat tomentose and borne on slender pedicels; calyx-lobes triangular-ovate and long-acuminate,¼ to ½ in. long, glandulose-denticulate; petals oval, short-clawed,¾ in. long; stamens about 20; styles 4 or 5, glabrous. Fruit subglobose, russet-brown; stalk slender; calyx deciduous.

This oriental pear has been referred to P. sinensis Lindley (not Poiret) by botanists and horticulturists since its introduction in Europe nearly one hundred years ago until 1915 when Rehder, discovering that the true P. sinensis had been lost to cultivation, proposed the name P. lindleyi for one group and P. serotina for another group of Chinese pears passing under Lindley’s original species, P. sinensis.

This species comes from central and western China, where the fruits are used for food under the name, with that of other brown-fruited species, of tang-li. American pomologists are interested in the type species as a possible source of blight-resistant stocks for varieties of the common pear. Stocks of this species, however, grown on the Pacific slope have not proved satisfactory because difficult to bud, and very susceptible to leaf-blight, and because they are not as resistant to pear-blight as an ideal stock should be. Rehder, an authority on oriental pears, gives two botanical varieties. His var. stapfiana differs from the type in bearing pyriform fruits; leaves with less appressed serratures; and petals with attenuate claws. So far as now appears it is of no greater value to pomology than the type. The other botanical variety which Rehder describes, var. culta, is of great importance in pomology and must have detailed consideration.

PYRUS SEROTINA CULTA Rehder

1. Rehder Prod. Amer. Acad. Arts & Sci. 50:233. 1915. 2. P. sinensis Hort. Not Lindley nor Poiret. 3. P. japonica Hort. Not Thunberg. 3. P. sieboldi Carrière Rev. Hort.. 110. 1880. 5. P. sinensis culta Makino Tokyo Bot. Mag. 22:69. 1908.

Tree large, vigorous; top spreading, drooping, open; trunk thick, shaggy; branches stout, zigzag, greenish-brown, with a slight covering of scarf-skin marked with many conspicuous, elongated lenticels; branchlets slender, with long internodes, brownish-red, tinged with green and with thin, ash-gray scarf-skin, glabrous, with many unusually conspicuous, raised lenticels. Leaf-buds sharply pointed, plump, thick at the base, free; leaf-scars prominent. Leaves 4⅛ in. long, 2⅝ in. wide, thick, leathery; apex taper-pointed; margin tipped with very fine reddish-brown glands, finely serrate; petiole thick, 2 in. long, lightly pubescent, greenish-red. Flower-buds thick, short, conical, plump, free, arranged singly on very short spurs; flowers with a disagreeable odor, bloom in mid-season, 1¼ in. across, averaging 7 buds in a cluster; calyx-lobes long, narrow, acuminate, glandular, reflexed, lightly pubescent within and without; petals broadly oval, entire, apex rounded; pistils 4 or 5, from a common base, longer than the stamens, pubescent at base; stamens ¼ in. long, with dull red anthers; pedicels 1½ in. long, slender, thinly pubescent, pale green.

Fruit ripe February-March; 2¼ in. long, 2⅛ in. wide, round, slightly pyriform, irregularly ribbed, with unequal sides; stem 1½ in. long, curved, slender; cavity acute, deep, narrow, furrowed, lipped; calyx deciduous; basin shallow, wide, obtuse, gently furrowed or wrinkled; skin tough, smooth, waxy; color lemon-yellow, with russet lines and nettings and many russet specks; dots numerous, small, conspicuous, brownish-russet; flesh yellowish-white, very granular, crisp, tough, juicy, with a peculiar aroma unlike that of the common pear; poor in quality. Core large, open, axile, with clasping core-lines; calyx-tube short, wide, conical; seeds roundish, of medium size, wide, plump, obtuse.

The Sand pear differs from the type in fruit and foliage. The pears are much larger and are commonly apple-form as shown in the accompanying plate, but trees bearing pyriform fruits are not unknown. The leaves are larger and broader. Rehder, who separated this form from its species, writes, “The Japanese pear cultivated under the name Madame Von Siebold may be considered as representing the type of this variety.” These pears are known to pomologists under several names; as Chinese Sand, Sand, Japanese, Hawaii, Sha Lea, Gold Dust, Mikado, and Diamyo, although it is possible that the last three are hybrids. The pear illustrated and described in this text as a representative of this botanical variety came from seed sent from Manchuria.

The pears are attractive in appearance, keep well, and are palatable in culinary preparations, but are possessed of a gritty flesh and potato-like flavor which debar them as dessert fruits in all regions where the common pear can be grown. The several varieties of var. culta now in America came from Japan where the species must have been early introduced from China as this is now the most common fruit of the Japanese with the exception of the persimmon. In China and Japan there are a number of pomological varieties, which, however, differ from each other less than varieties of the European pear. The fruits of the several varieties grown in America are often mistaken for apples, from which they are distinguished by their deciduous calyxes, rough, dry skins, long stems, juicy, gritty flesh, and insipid potato-like flavor. Seedlings of var. culta fail as stocks for European varieties in the same characters in which the species is unsatisfactory.

This oriental pear hybridizes freely with the common pear, and it is for this purpose that it is most valuable in America. Several of these hybrids are important commercial varieties in North America of which Kieffer, Le Conte, and Garber, in the order named, are the best known and the most useful. Sterility is a common attribute of hybrids, but the hybrids between these two species are not more sterile than varieties of the parents. These hybrids are stronger and more rapid in growth than the common pear and are more productive and more resistant to blight. The pears are more pyriform and of much better flavor than those of the oriental parent. The calyx of hybrid fruits is sometimes persistent and sometimes deciduous. The hybrids do not make good stocks and intergraft but poorly with the common pear. Of all pear-trees, these are handsomest in growth when in perfect health and make excellent ornamental trees. The strong, clean growth, luxuriant green foliage, beautifully tinted in the autumn, resembles the oriental rather than the occidental parent. It is doubtful whether hybrid trees will attain the great size of those of the common pear, and they seem to succumb to the ills of old age rather more quickly than those of the European parent. The hybrid pears seem less well liked by the pestiferous San Jose scale than the common pear. The first flush of popularity having passed, hybrid pears have found their proper place in American pomology. They belong to the South and Middle West where the common pear is illy adapted to the climate. In the North and on the Pacific slope, pear-growers are wisely planting varieties the fruits of which are better in quality.

5. PYRUS USSURIENSIS Maximowicz

1. P. ussuriensis Maximowicz Bull. Acad. Sci. St. Petersb. 15:132. 1857. 2. P. sinensis Decaisne Bull. Acad. Sci. St. Petersb. 19:172. 1883. 3. P. simonii Carrière Rev. Hort. 28. 1872. fig. 3. 4. P. sinensis ussuriensis Makino Tokyo Bot. Mag. 22:69. 1908.

Rehder says of P. ussuriensis,[15] “This species differs from the allied species chiefly in the short stalk of the globose fruit with persistent calyx, in the broad, often nearly orbicular, strongly setosely serrate leaves and in the lighter yellowish-brown branches; the flower clusters are, owing to the short stalks, rather dense and hemispherical, the petals are obovate and rather gradually narrowed toward the base; the styles are distinctly pilose near the base.”

Wilson,[16] describing the vegetation of Korea, says of this species: “Pyrus ussuriensis is abundant and this year is laden with fruit. On some trees the fruit is wholly green, on others reddish on one side; the length of the peduncle varies and the same is true of the leaf-structure; the calyx is persistent or deciduous often on fruits on the same branch.”

The habitat of this species is northern and northeastern China and eastern Siberia. Manchuria, Korea, Amurland, and Ussurri are named as regions in which it is most commonly found. A glance at the map shows that this habitat is in the far north for pears, and it might well be suspected that this would be one of the hardiest of all pears, and this proves to be the case. Horticultural varieties are reported by Chinese explorers, some of which have been introduced by the United States Department of Agriculture. These no doubt have some value in the most northern fruit regions of America and if not for their fruits, they may prove useful in hybridization. But it is as a possible stock resistant to blight that the species has received most attention in this country.

Reimer, of Oregon, found this species to be very resistant to fire-blight and at first thought it might prove to be a valuable stock. Following Reimer’s experiments much was said of it as a promising new stock, and the United States Department of Agriculture gave it a thorough trial from the results of which they discouraged its use. The tree proved to be a slow grower; very subject to leaf-blight, therefore unable to hold its leaves during the growing and budding season, difficult to use in budding as the tough bark did not “slip” easily, and but a small number of the buds took. According to Galloway,[17] however, the Kuan li or Chinese water pear, which he says belongs to the Ussuriensis group, is one of the most promising pear stocks. Both for its fruits and as a stock, this species is likely to receive much attention in the United States for some time to come. The difficulty at present, as we have found at this Station, is to get seeds or budding wood true to name of the forms of the species that seem to be most desirable.

6. PYRUS SERRULATA Rehder

1. P. serrulata Rehder Proc. Amer. Acad. Arts & Sci. 50:234. 1915.

Chinese Saw-leafed Pear. This species, according to Rehder, is closely related to P. serotina but differs from it chiefly in its serrulate, not setosely serrate, generally broader, leaves, in the smaller flowers with usually three or four styles, and in the shorter sepals and smaller fruit.

This pear was first found by E. H. Wilson in 1907 in western Hupeh. The province of Hupeh is 800 or 900 miles west and south of Shanghai. The pears in this location grow in thickets at an altitude of 4000 to 5000 feet. Reimer found the species at Ichang, in Hupeh, at elevations of 3000 to 3700 feet. Its occurrence at these altitudes indicates that it is a hardy form. Whether the species is likely to be valuable for its fruits, or for hybridization, does not appear, but Galloway,[17] reporting on it as tested by the United States Department of Agriculture, says that it is affected but slightly by leaf-blight, holds its foliage well in hot summers, and has a long budding season. These statements indicate that it is worth trying as a stock.

7. PYRUS BETULÆFOLIA Bunge

1. P. betulæfolia Bunge Mem. Sav. Etr. Acad. Sci. St. Petersb. 2:101. 1833. 2. Decaisne Jard. Fruit. 1:20. 1872. 3. Carrière Rev. Hort. 318. 1879. figs. 68, 69. 4. Sargent Gard. & For. 7:224. 1894. fig. 39.

Tree vigorous, upright-spreading, tall, open-topped, hardy; trunk stocky, shaggy, and rough; branches thick, dull brownish-red, thickly coated with gray scarf-skin, sprinkled with numerous small, raised lenticels; branchlets slender, willowy, long, with long internodes, dull reddish-brown, with gray scarf-skin, heavily pubescent, with small, conspicuous, raised lenticels. Leaf-buds small, short, flattened, pointed, free. Leaves 4 in. long, 2⅛ in. wide, thick, stiff; apex taper-pointed; margin sharply and coarsely serrate; teeth tipped with small, reddish-brown glands; petiole 1¾ in. long, slender, pubescent, tinged red. Flower-buds small, short, conical, plump, free, arranged singly on long spurs; flowers open late, with a rather unpleasant odor, showy, 13⁄16 in. across, white, in dense clusters, 13 buds in a cluster; pedicels 15⁄16 in. long, slender, pubescent, pale green; calyx-tube pale green mingled with white pubescence, dark greenish-yellow within, campanulate, thickly pubescent; calyx-lobes greenish within and with white pubescence, short, narrow, acuminate, tipped with very small, sharp, reddish-brown glands, heavily pubescent within and without, reflexed; petals separated at the base but with meeting cheeks, round-oval, entire, with short, narrow claws, white at the base; anthers deep pinkish-red; filaments short, shorter than the petals; styles 2 to 3; pistils glabrous, usually as long as the stamens; stigma very small. Fruit russet, heavily dotted, the size of a small grape; calyx deciduous; pears hanging until the following spring.

The above description was made from a plant grown from seed obtained from the Arnold Arboretum in 1900, that institution having obtained the species from the mountains near Peking in 1882. This pear has been collected by various explorers in the regions about Peking, especially to the north and east, and is not uncommon in these parts of China. The small pears are without value for food, but the trees are promising stocks. While Reimer reports the species as susceptible to fire-blight in Oregon, it has not proved particularly so on the grounds of this Station nor elsewhere in the East. The seedlings are also free from leaf-blight. The young plants grow vigorously from seed or cuttings; are capable of being budded throughout a long season; they make a good union with other pears in China according to Reimer; and the variety is so common in China that there is little difficulty in getting seed true to name. The tree is a handsome ornamental.

8. PYRUS CALLERYANA Decaisne

1. P. calleryana Decaisne Jard. Fruit. 1:8. 1872.

Rehder[18] says of this species, “Pyrus calleryana is a widely distributed species and seems not uncommon on mountains at an altitude of from 1000 to 1500 m. It is easily recognizable by its comparatively small crenate leaves, like the inflorescence glabrous or nearly glabrous, and by its small flowers with two, rarely three styles. When unfolding most specimens show a loose and thin tomentum on the under side of the leaves which usually soon disappears, but in No. 1662 from Kuling even the fully grown leaves are loosely rusty tomentose on the midrib beneath. In No. 415a the leaves are longer, generally ovate-oblong, the pedicels very long and slender, about 3 to 4 cm. long and the sepals are mostly long-acuminate. The fruit of No. 556a is rather large, about 1 to 1.4 cm. in diameter, but a fruit examined proved to be two-celled.”

This species is reported from various places in China with western Hupeh as the chief habitat. Reimer,[19] of Oregon, reports this as a most promising stock for the common pear, and Galloway,[20] of the United States Department of Agriculture, says that “Of all the pears tested and studied this remarkable species holds out the greatest promise as a stock.” In America it stands the cold as far north as the Arnold Arboretum, near Boston, and endures summer heat as far south as Brooksville, Florida. The plant is reported as vigorous under nearly all conditions. Galloway reports that it can be budded from July 1 to September 1 at Washington. All kinds of pears take well upon it; the seeds are easily obtained, easily grown, and run remarkably uniform.

9. PYRUS OVOIDEA Rehder

1. Proc. Am. Acad. Arts & Sci. 50:228. 1915. 2. P. sinensis Hemsley Jour. Linn. Soc. 23:257. 1887, in part. Not Poiret nor Lindley. 3. Schneider Ill. Handb. Laubholzk. 1:663. 1906. fig. 364 c-d. 4. P. simonii Hort. Not Carrière.

Rehder, who established this species, says of it: “This species seems to be most closely related to P. ussuriensis Maximowicz which differs chiefly in the broader orbicular-ovate or ovate leaves, in the lighter colored branches, and in the short-stalked subglobose fruit with the persistent sepals spreading. The shape of the fruit of P. ovoidea is very unusual and quite distinct from any pear I know; the fruit is exactly ovate, broad and rounded at the base and tapering from the middle toward the truncate apex, as figured by Schneider (fig. 364 d). This may, however, not be a specific character and the shape of the fruit may vary in other specimens referable to this species. The Chinese material which I have seen and which might belong here is very meagre. The Fokien specimen is in young fruit which suggests a more pyriform shape, though tapering toward the apex and showing the same kind of persistent calyx; the serration of the leaves is more minute and more accumbent. The Yunnan specimen is in flower and differs somewhat in the more copious tomentum of the leaves and of the inflorescence and in the shorter, nearly entire calyx-lobes.

“It is not known when and whence this species was introduced. Possibly it was sent in the early sixties from northern China by G. E. Simon, or by A. David a little later from the same region or from Mongolia to the Museum in Paris and was afterwards distributed by Decaisne.”

This species is of importance to pear-growers as a stock. Discussing it as a stock, Reimer[21] says: “This species ranks second only to Pyrus ussuriensis in blight resistance. During 1915 we were unable to get the disease to develop more than four inches even in vigorous growing shoots of this species. During the very favorable season of 1916 vigorous shoots would blight down as much as fifteen inches. As soon as it reached the hard wood of the previous season it would stop. All the inoculations into one and two-year-old trunks have failed to develop the disease.

“The trees are vigorous growers, and produce medium sized fruit, which is egg-shaped, and has a persistent calyx. This species is a native of northern China, and was formerly known as Pyrus simonii.”

10. PYRUS VARIOLOSA Wallich

1. Cat. No. 680. 1828.

Reimer,[21] now a leading authority on blight-resistant stocks, writes of P. variolosa: “This species is one of the most promising types in our collection. The tree is a beautiful, vigorous, upright grower. It makes a good union with cultivated varieties, and should prove valuable as a stock for top-working.

“This species, while not immune to blight, is very resistant. During the summer of 1915 a large number of innoculations were made into the tips of young branches, and these usually would blight back for a distance of three to five inches. During 1916, a very favorable season for pear blight, the disease would extend down young branches as much as from twelve to eighteen inches, and in one case as much as two feet. Seventy-seven inoculations were made into the trunks of two-year-old trees. All but seven of them failed to develop the disease. In the successful infections, only small superficial cankers were produced. In these cankers a new cambium would readily form, and the entire wound would heal over perfectly in a short time.

“The origin of this species, or type, is still a matter of dispute. It has been confused with Pyrus pashia of northern India, from which species it is very distinct. Pyrus variolosa produces medium sized, pear-shaped fruits, which have a persistent calyx. It is possible that this is not a distinct species, but a hybrid. If this should prove to be the case, it probably will not come true to type from seeds. This matter will be determined by a study of the seedlings of this type. If this does not come true to type from seeds, the seedlings may be of little value for root stocks. If this should prove to be the case, it will, nevertheless, be of value as a stock for top-working, when propagated by budding or grafting on some other root system.”