|Standard Cyclopedia of Horticulture|
Picea (ancient Latin name derived from pix, pitch). Pinaceae. Spruce. Ornamental trees, grown for their evergreen foliage and regular pyramidal habit; many species are valuable timber trees.
Evergreen trees with usually whorled spreading branches: lvs. usually 4 angled with white lines formed by numerous stomata arranged in rows and on all 4 sides, or compressed and stomatiferous only on the upper or ventral side which, on the lateral branchlets, by twisting of the lf. stalk appears to be the lower one. sessile and jointed at the base to a short stalk projected from a prominent cushion called a pulvinus: fls. monoecious, catkin like, terminal or axillary; the staminate yellow or red, consisting of numerous spirally arranged anthers with the connective enlarged at the apex and scale like; the pistillate greenish or purple, consisting of spirally arranged scales each subtended at the base by a small bract and bearing 2 ovules at the inner side: cones pendulous or spreading, with persistent scales not separating from the axis after shedding the seeds, which are provided with a large and thin obovate or oblong wing. Thirty-eight species in the colder and temperate climates of the northern hemisphere from the arctic circle to the high mountains of the temperate regions. They are all mentioned below and all of them except 4 are in cult. The names Picea and Abies are often exactly transposed by horticulturists and others.
The spruces are usually tall trees of pyramidal habit, sometimes dwarfed in horticultural varieties or in alpine forms, with spreading usually whorled branches clothed densely with acicular spirally arranged leaves. The catkin-like flowers appear in spring and are often very conspicuous by their bright red color. These are followed by usually pendent cones, green or purple before ripening and light to dark brown at maturity. The spruces are not only highly ornamental, but also very valuable forest trees, and as inhabitants of cooler climates they are especially adapted for cultivation in northern regions. Almost all are hardy North, except P. sitchensis, P. Smithiana and P. spinulosa, but they do not resist heat and drought well; some, however, as P. pungens. P. canadensis, P. Omorika, P. orientalis, P. excelsa, and some of the recently introduced Chinese species grow better in a drier climate than most others. For ornamental park planting the spruces belong to the most valuable evergreens on account of the symmetrical habit and rapid growth of most species. Only a few, like P. orientalis, P. obovata, P. Omorika, and P. polita, are of slower growth and therefore well suited for smaller parks and gardens; and so are the numerous horticultural forms, which are mostly dwarf and slow growing and sometimes more interesting and curious than beautiful. The spruces are often planted as shelters and windbreaks, and also used for hedges, especially P. excelsa, which makes a very dense and durable hedge when regularly trimmed. P. polita is also recommended as a good hedge plant and seems well adapted, with its rigid spiny leaves. The spruces thrive best in moderately moist sandy loam, but will grow in almost any kind of soil provided it contains enough moisture; wet and dry soils are equally unfavorable. Slopes of northern aspect are well suited for spruces, and they thrive better in shady positions than most other conifers. As the roots mostly spread horizontally near the surface, the spruces will grow in shallow soil and are easily transplanted even as rather large plants; they may be moved with success at any time of the year except when the young shoots are growing, but if possible avoid transplanting shortly before dry weather is expected to set in.
Spruces are propagated by seeds, which ripen in fall and are usually kept dry and cool during the winter and sown in spring outdoors in prepared beds or in frames or boxes. The young seedlings should be shaded and watered in dry weather and may remain a year or two before being transplanted in nursery rows when not sown too thickly. Varieties and rarer kinds are often increased by layers or by grafting on seedling stock of P. excelsa. P. canadensis is used for forms of this species and for P. mariana and P. rubra. Veneer-grafting in spring or August in the greenhouse is usually employed; less commonly cleft-grafting with half-hardened wood. The dwarf forms grow readily from cuttings under glass in August or fall and given slight bottom heat in early spring; also most other forms and species, especially those with thinner and finer branches, can be raised from cuttings.
The spruces are important timber trees. The soft and light straight-grained wood is much used for construction, the interior finish of houses and for fuel, also for ship-building; but it is not durable in the ground. The bark of some species is used for tanning leather, and the resinous exudations are sometimes employed in medicine. From the red and black spruce, spruce beer is made by boiling the branches with honey. Spruces are often known in nurseries, especially in this country, under the name of Abies.
The grafting of piceas. (E. P. Drew.)
In the writer's experience, P. canadensis is a good stock on which to graft the finer varieties of spruce or those having four-sided leaves. Pot the stock the last of August, keep in shaded frame, syringe till danger of wilting is over and harden gradually. Be careful not to keep the earth in the pots too wet, as roots are liable to rot. Place the stocks in greenhouse after light frosts, and graft as soon as roots have started about last of January generally. Do not wait until buds have made much growth, for then the sap will be running strongly to the upper buds, leaving the cion to remain dormant. When stock and cion are of same size, the veneer-graft may be used. In large stocks, use slit or side graft. Be sure that the knife is sharp enough to shave dry wood. Cut the cion in elongated wedge shape; place it in the cleft by twisting the stock with left hand, fitting the cion exactly with the right. Be careful to wax well, as a hole the size of a pin left on the cut surface will be fatal to the cion. Place the grafted plants in a close frame until the cion is well started. Syringe from two to three times a day, shading when too hot. Give air gradually until well hardened. Do not cut back the stock for one year, as the cion may make second growth and winterkill. If cion should die, do not use the stock again until after a year's rest, as two consecutive pottings will usually ruin the plant; this holds good only with Tsuga and P. canadensis. The above method can be used with equal success on Pinus, Abies, Juniperus, and other evergreens propagated by grafting.
Ornamental value of spruces. (Thomas H. Douglas.)
The piceas embrace some of the most useful as well as ornamental trees of the conifer family. They cover a great variety of forms, from the stiff-branched sturdy and rugged P. pungens to the lithe graceful and drooping P. Breweriana. The American species comprise P. mariana, P. canadensis, P. rubra, P. pungens, P. Engelmannii, P. Breweriana, and P. sitchensis. The grand and towering Douglas spruce and the graceful hemlock spruce; so called, are not true spruces and will not be noticed in this article.
The white spruce, Picea canadensis, is a native of the northern parts of America and is justly thought to be one of our best conifers, a compact and upright grower of great longevity; trees growing at Waukegan, Illinois, of mature age, are well branched at the bottom, retain their pyramidal form, and annually make an upward growth. It is the most aromatic of the piceas; in fact, this odor is often used to identify it while young from the Norway spruce or Engelmann's spruce. It grows on a great variety of soils, bears crowding well and also will stand severe pruning; hence it is used for windbreaks and hedges. Seedlings vary considerably in color, some of them fairly rivaling the blue form of the P. pungens. This tree, being a native of a cold climate, is subject to the ravages of the red-spider in a warm climate and should not be planted south of Philadelphia or St. Louis. There is a variety of P. canadensis found in the Black Hills that stands extreme drought better than the northern form and is largely planted on the dry prairies of Nebraska and the Dakotas. It does not, however, do so well in northern Illinois or farther east as the northern variety.
Picea Engelmannii, one of the gems of Colorado, resembles P. canadensis more than it does its near neighbor, P. pungens, being of finer foliage and not so stiff- branched as the latter. It is one of the few conifers that will stand the extreme cold of Petrograd, Russia, but on our western rairies it soon loses its lower branches, as it seems to be unable to withstand the hot and drying winds of that section in late summer and early autumn. In the eastern states, however, it does not have this fault, as the cooler and more humid air seems better to agree with it.
Another Colorado conifer, P. pungens (the blue form being called by some the "queen of the piceas"), is a striking and noble tree, seeming to be hardy wherever tested and on all varieties of soil. Strong, sturdy, and upright in growth, its form alone would make it a striking figure in any landscape. Its beautiful color varies from a light silvery hue in some specimens to a dark blue, almost purple in others. In some specimens the branches are in distinct and regular whorls, resembling Araucaria excelsa. Undoubtedly the oldest and finest specimens of this grand tree are found on the formar grounds of the late Robert Douglas, at Waukegan. Illinois. These trees are now 35 to 40 feet high and show no signs of weakness anywhere, being one mass of foliage from the ground upward. The green form of P. pungens is an excellent tree, but is not so much appreciated by planters and lovers of trees as it should be, as it is always compared to its more striking variety, the blue spruce. There is a fine specimen growing on the above grounds, even larger than the blue form, which does not suffer in comparison with its near neighbors, Abies concolor, A. Fraseri, Picea Engelmannii, Tsuga canadensis or hemlock spruce, Pseudotsuga Douglasii or Douglas spruce, and Pinus Strobus, all large and fine specimens, equal to any in the Middle West.
Picea mariana, or black spruce, is undoubtedly the poorest tree of the genus from a landscape gardener's point of view. It has very short needles and is greatly disfigured by its cones, which hang on for several years. It begins seeding when very young and is an exceedingly slow grower. Some good specimens of it are found, however, in the East, but in very restricted localities. P. rubra, long thought to be a variety of the preceding, is a much better tree in every respect, resembling P. excelsa in color and form. It seems to be a shortlived tree, especially in the West. This tree is undoubtedly the least known of the American piceas. P. sitchensis of the Pacific Coast strongly resembles P. pungens; in fact, when the latter was first Introduced it was thought to be a variety of P. sitchensis. It has much finer branches and needles than P. pungens, varies in coloring as much as the latter, and, where hardy, makes a very fine tree. Unfortunately it is not hardy in any of the northern states. Unlike P. pungens, it will not stand close planting, as the needles fall off badly where the branches are rubbed together by the wind or strike other objects.
Without doubt the most graceful and elegant picea is P. Breweriana, or weeping spruce, a native of the Siskiyou and Coast Ranges of mountains in northern California and Oregon. It has the true spruce form, tall and symmetrical, with horizontal branches and a beautiful dark green color. In its general features it resembles a well-grown specimen of the Norway spruce, but its distinguishing beauty is in the long pliant pendulous branchlets which hang straight down from the branches to a length of 6 to 8 feet and no larger around than a lead pencil. It has a stately grace in calm weather, but its characteristic impressiveness is seen only when the long flexible branches are undulating in a light breeze or streaming before a gale. The bark is smooth and reddish in color, adding to its beauty where glimpses of it can be seen through the green foliage. It grows only at high elevations in its native habitat and on the northern slope of the mountains where the annual fall of snow is 15 to 25 feet. The cones are from 2 1/2 to 3 1/2 inches long, of a purplish color, and as they grow only on the tips of the branches they add greatly to its beauty. Unfortunately this beautiful tree has not proved satisfactory. Out of over 300,000 seedlings raised in 1893, only one plant is now alive; it is growing on the Douglas grounds and is scarcely 5 feet tall, having cost over $100 a foot, and this is doubtless one of the largest specimens in cultivation.
Of the foreign piceas, P. excelsa is most popular: in fact is the best known and most largely planted of any of the genus. It makes a large fine-looking tree, grows in a great variety of soils, is hardy throughout most of North America, is the most rapid grower of any of the piceas, and stands close planting very well. It is used more than any other tree for windbreaks and shelter-belts. It bears pruning well. Hedges of this species and P. canadensis that have been planted more than forty years are growing on the Douglas grounds that are now 8 feet high, and 9 1/2 feet across the base. One fine specimen tree on these grounds measures about 63 feet high and 64 feet from tip to tip of its lower branches. Other foreign species, but not so well known nor so thoroughly tested as the preceding, are P. obovata, a close compact-growing tree dark green in color. P. Smithiana or P. Morinda is one of the handsomest of the piceas, but is not hardy in the northern states, plants from seed collected at an elevation of 8,000 feet on the Himalaya Mountains not proving hardy. Fine specimens of this tree are found in California, where it is justly prized. P. Omorika from southeastern Europe is one of the best of the hardy foreign piceas; it does well in the eastern states and forms a narrow pyramid with slender branches clothed with dark glossy foliage. There are several species of Picea from China and Japan that will doubtless prove hardy in the eastern states. Of these P. jezoensis var. hondoensis has proved one of the best in the eastern states; also P. bicolor, which forms a handsome pyramidal-tree of rapid growth with dark green foliage, has proved perfectly hardy. All piceas will stand the pruning-knife, but this should be used not later than July 1 in the northern states and earlier farther south. They are propagated from seed the same as larix; and their varieties, of which there are a great number, are either grafted or raised from cuttings over bottom heat. CH
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1 Cones with thickish scales; leaves quadrangular in cross-section: section Picea
- 1a Cones with (mostly) pointed scales; leaves blunt or somewhat pointed
- Picea abies Norway Spruce. Europe; important in forestry. The original Christmas tree.
- Picea asperata Dragon Spruce. Western China; several varieties.
- Picea meyeri Meyer's Spruce. Northern China.
- Picea koraiensis Korean Spruce. Korea, northeast China.
- Picea koyamae Koyama's Spruce. Japan (mountains).
- 1b Cones with smoothly rounded scales; leaves blunt or somewhat pointed
- Picea orientalis Caucasian Spruce or Oriental Spruce . Caucasus, northeast Turkey.
- Picea morrisonicola Yushan Spruce . Taiwan (high mountains).
- Picea wilsonii Wilson's Spruce . Western China.
- Picea obovata Siberian Spruce. North Scandinavia, Siberia. Often treated as a variant of P. abies (and hybridises with it) but distinct cones.
- Picea schrenkiana Schrenk's Spruce. Mountains of central Asia.
- Picea smithiana Morinda Spruce. Western Himalaya.
- Picea alpestris Norway Spruce, Alpine Spruce. The Alps in Europe; rare, often treated as a variant of P. abies (and hybridises with it) distinct cones.
- 1c Cones with smoothly rounded scales; leaves viciously sharp-pointed
- Picea maximowiczii Maximowicz Spruce. Japan (rare, mountains).
- Picea torano Tiger-tail Spruce. Japan.
- Picea neoveitchii Veitch's Spruce. Northwest China (rare, endangered).
- Picea martinezii Martinez Spruce. Northeast Mexico (very rare, endangered).
- Picea chihuahuana Chihuahua Spruce. Northwest Mexico (rare).
2 Cones with thickish wavy scales, leaves slightly to strongly flattened: section Omorika
- 2a Cones mostly with rounded scales; leaves flattened in section, white below
- 2b Cones mostly with wavy scales; leaves slightly flattened in section, often paler below
- Picea mariana Black Spruce. Northern North America.
- Picea rubens Red Spruce. Northeastern North America; important in forestry.
- Picea glehnii Glehn's Spruce. Northern Japan, Sakhalin.
- Picea alcockiana ("P. bicolor") Alcock's Spruce. Central Japan (mountains).
- Picea purpurea Purple Spruce. Western China.
- Picea balfouriana Balfour's Spruce. Western China.
- Picea likiangensis Likiang Spruce. Southwest China.
- Picea spinulosa Sikkim Spruce. Eastern Himalaya.
3 Cones with very thin, wavy scales: section 'Casicta'
- Picea glauca White Spruce. Northern North America; important in forestry.
- Picea engelmannii Engelmann Spruce. Western North American mountains; important in forestry.
- Picea sitchensis Sitka Spruce. Pacific Coast of North America; the largest species, to 95m tall; important in forestry.
- Picea jezoensis Jezo Spruce. Northeast Asia, Kamchatka south to Japan.
- Picea pungens Blue Spruce or Colorado Spruce. Rocky Mountains, North America; important in horticulture.
|Standard Cyclopedia of Horticulture|
For names not found here or in the supplementary list, consult Abies and Tsuga.
Abies . 5. Ellwangeriana, 5. nova, 16. acicularis, 16. Engelmannii, 11. nutans, 7. ajanensis , 14. erecta, 5. obovata,2, 6. alba, 10. erythrocarpa, 5. Omorika, 17. albertiana, 10. excelsa, 5, 6. orientalis,7. Alcockiana, 14, 16. fastigiata, 0. Parryana, 12. alpestris, 5. fennica, 5. pendula. 5, 10,12. argentea. 10, 11, 12.finedonensis, 5. polita, 3. argenteo-spicata, 5. flavescens, 12. ponderosa, 4. asperata, 4. glauca, 10,11, 12. procumbens, 5. aurea, 5, 12. globoea, 2. pseudopungens, 11. aureo-spicata, 7. Gregoryana, 5. pumila, 9. australis, 8 hondoensis, 14. pungens, 12. Barryi, 5. inversa, 5. purpurea, 15. Beissneriana, 9. japonica, 16. pygmaea, 5. bicolor, 3, 16. jezoensis, 14. pyramidalis, 5. brevifolia, 9. Khutrow, 1. reflexa, 5, 16. Breweriana, 18. Kosteri, 12. Remontii, 5. caerulea, 10, 12. laxa, 10. repens, 5. canadensis, 10. mariana, 9. rubens, 8. capitata, 5. Maxwellii, 5. rubra, 5. 8. 10. chlorocarpa, 5. medioxima, 5. Schrenkiana, 2. Clanbrasiliana, 5. Mensiesii, 12, 13. semi-virgata, 7. columbiana, 11. microsperma, 14. sitchensis, 13. columnaris, 5. Moerheimii, 12. Smithiana, 1. commutata, 11, 12. monocaulis, 5. speciosa, 13. compacta, 5, 12. monstrosa, 5. tabuliformis, 5. conica, 5. Morinda, 1. Torano. 3. cupressina, 5. mutabilis, 5. viminalis, 5. denudata, 5. nana, 5, 7, 9. violacea, 10. Doumetii, 9. nigra, 9. virgata. 5, 8. dumosa, 6. notabilis, 4. viridis, 12. elata. 5.
Section I. Eupicea, Willk.
Lvs. quadrangular, with stomata on all 4 sides: scales of cone closely appressed before maturity, broad and entire or nearly so.
The Roman figure indicates the section to which the species belongs: P. ascendens, Patschke. (Section III.) Tree, to 80 ft.: branchlets pale brown, glabrous: lvs. about 3/4 in. long, compressed, with 2 white lines above: cones 3-4 in. long, with obovate truncate scales. W.China.—P. aurantiaca. Mast. (I.) Allied to P. asperata. Tree, to 40 ft., with pale gray bark: branchlets orange, glabrous: lvs. quandrangular, about 1/2 in. long: cones 4—5 in. long, brown, with broad, rounded, slightly erose scales. W. China,—P. Balfouriana, Rehd. & Wilson. (II.) Allied to P. purpurea. Tree, to 120 ft.: branchlets villous, yellowish: lvs. 1/3 - 1/2 in. long, compressed, whitish above, acute or obtusish: cones purplish, 2-3 1/2 in. long, with rhombic denticulate scales. W. China.—P. brachytyla, Priti. (P. pachyclada, Patschke). (III.) Tree, to 70 ft.: branchlets brown, nearly glabrous: lvs. Hin. long, compressed, white above: cones 3-4 in. long, with obovate scales entire at the margin. W. China.—P. complanata, Mast. (III.) Tree, to 80 ft., with gray bark: branchlets orange-brown, pubescent or sometimes glabrous: lvs. flattened, acute, white above, 3/4in. long: cones reddish brown, 5-6 in. long, with broad rounded or truncate scales. W. China. G.C. III. 39:147.—P. glehnii. Mast. (III.) Tree, to 150 ft.: branchlets brown, pubescent: lvs. 1/4 in. long, obtusely quadrangular, whitish above, green beneath: cones brown, violet-purple while young, 1 1/3 -2 in. long, with broad rounded erose scales. Amurl, Saghalin, N. Japan. G.C. II. 13:301. S.I.F. 2:3.—P. hcterolepis, Rehd. & Wilson. (I.) Allied to P. asperata. Tree, to 8O ft.: branchlets brownish, glabrous: lvs. quadrangular, thick, pungent, 1/2 - 1/4in. long: cones 3 1/2 - 5 1/3 in. long, pale brown, with rigid rhombic-obovate scales, emarginate or bifid at the apex. W. China, —P. Koyamai, Shirasawa. (III.) Allied to P. Glehnii. Tree, to 30 ft.: branchlets bright reddish brown, glabrous: lvs. quadrangular, 1/3 - 1/2in. long, acutish, bluish white above: cones light brownish green, 1 1/2 -2 1/2 in. long: scales broadly obovate, rounded, entire. Cent. Japan. M.D. 1914:257.—P. likiangensis, Prits. (II.) Tree, to 80 ft.: branchlets light yellow-gray, sparingly hairy: lvs. quadrangular, slightly compressed, 1/3 in. long, white above: cone about 2 in. long with rhombic-ovate, erose, flexible scales. W. China.—P. Mastersii, Mayr equals P. Wilsonii.—P. Maximowicxii, Regel (P. Tschonoskii, Mayr. P. excelsa var. obovata japonica, Beissn.). (I.) Allied to P. obovata. small bushy tree: branchlets reddish brown, glabrous: lvs. rigid, pointed, spreading, about 1/2in. long: cones 1 1/4-2 in. long, lustrous brown, with broad rounded scales. Japan.—P. Meyeri, Rehd. and Wilson. (I.) Allied to P. asperata. Medium-sized tree: branchlets cinnamon-brown, hairy: lvs. quadrangular, slightly compressed, curved, obtusish. 1/3- 3/4in. long: cones 2 -2 1/2 in. long, lustrous brown, with rounded or truncate scales. N.China.—P. momtioena. Mast. (II.) Tree, to 100 ft.: branchlets pale brown, hairy: lvs. quadrangular, 1/2 in. long, curved, acutish: cones brown, 3—4 in. long, with rhombic-ovate, flexible, erose scales. W. China. G.C.III. 39:146 (except the cone).—P. monrindoides, Rehd. equals P. spinulosa.—P. Moseri. Mast. (P. jesoensis X P. mariana Doumetii). Branchlets smooth, olive: lvs. quadrangular, acute, 1/3-3/4 in. long, glaucous above, green below. Garden origin. J.H.S. 26:105.—P. pachyclada, Patschke (equals P. brachytyla).—P. retrofiexa, Mast. (I.) Tree, to 120 ft.: branchlets glabrous, rarely slightly hairy, bright yellow, rarely brownish orange: lvs. quadrangular, pungent, 1/2-1 in. long: cone lustrous brown, 3-4 1/2 in. long, with obovate, rounded, stiff scales. W. China.—P. Sargen- tiana, Rehd. A Wilson. (III.) Tree, to 70 ft: branchlets yellow or orange, glandular: lvs. compressed, acutish or obtuse, about 1/2in. long, white above, lustrous green beneath: cones 2 1/2-5 in. long, brown, with obovate, rounded or truncate scales. W. China.—P. spinulosa, Griff. (P. morindoides, Rehd.). (III.) Tree, with spreading branches and slender pendulous branchlets: lvs. 1-1 1/2 in. long, pungent, slightly compressed, glaucous above: cone 3—4 in. long, yellowish brown, with rhombic obovate scales minutely denticulate. E. Himalayas. B.M. 8169. G.C. III. 39:218, 274. R.H. 1908, p. 517. G.M. 51:47. S.T.S. 1:48. Tender.—P. Tschonoskii, Mayr (equals P. Maximowicsii).—P. Watsoniana, Mast. (I.) .Tree, to 40 ft.: branehlcts glabrous: lvs. quadrangular, slender, W in. long, bright green: cones 2-2 1/2 in. long with obovate, rounded scales. W. China.—P. Wilsonii, Mast. (P. Mastersii, Mayr). (I.) Tree, to 80 ft.: branchleta glabrous, pale gray: winter buds ovoid, dark brown, lustrous: lvs. quadrangular, curved, acute, 1/2 in long: cones cylindric-oblong, 1 1/3 -2 in., brown; scales suborbicular, entire, finally recurved at margin. Cent. China. G.C. 111.33:133. Not in cult, are the following species: P. gemmata, Rehd. & Wilson, P. hirtella, Rehd. & Wilson, P. Neoveitchii. Mast. (G.C. III. 33:116), from China, and P. morrisonicola, Hayata, from Formosa. CH
- Standard Cyclopedia of Horticulture, by L. H. Bailey, MacMillan Co., 1963