Gladiolus

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Gladiolus 7-19-06.JPG


Plant Characteristics
Habit   bulbous

Lifespan: perennial
Origin: Africa, Eurasia
Cultivation
Exposure: sun
Water: moderate
Features: flowers, naturalizes
Flower features: red, orange, yellow, green, blue, purple, brown, black, multicolored, pink, white, single
Scientific Names

Iridaceae >

Gladiolus >


Gladiolus (from Latin, the diminutive of gladius, a sword) is a genus of perennial bulbous flowering plants in the iris family (Iridaceae).[1] Sometimes called the sword lily, the most widely used English common name for these plants is simply gladiolus (plural gladioli, gladioluses or sometimes gladiolas).

The genus Gladiolus contains about 260 species, of which 250 are native to sub-Saharan Africa, mostly South Africa. About 10 species are native to Eurasia. There are 160 species of Gladiolus endemic in southern Africa and 76 in tropical Africa. The flowers of unmodified wild species vary from very small to perhaps 40 mm across, and inflorescences bearing anything from one to several flowers. The spectacular giant flower spikes in commerce are the products of centuries of hybridisation, selection, and perhaps more drastic manipulation.

These attractive, perennial herbs are semihardy in temperate climates. They grow from rounded, symmetrical corms, that are enveloped in several layers of brownish, fibrous tunics.

Their stems are generally unbranched, producing 1 to 9 narrow, sword-shaped, longitudinal grooved leaves, enclosed in a sheath. The lowest leaf is shortened to a cataphyll. The leaf blades can be plane or cruciform in cross section.

The fragrant flower spikes are large and one-sided, with secund, bisexual flowers, each subtended by 2 leathery, green bracts. The sepals and the petals are almost identical in appearance, and are termed tepals. They are united at their base into a tube-shaped structure. The dorsal tepal is the largest, arching over the three stamens. The outer three tepals are narrower. The perianth is funnel-shaped, with the stamens attached to its base. The style has three filiform, spoon-shaped branches, each expanding towards the apex.

The ovary is 3-locular with oblong or globose capsules, containing many, winged brown, longitudinally dehiscent seeds. In their center must be noticeable the specific pellet like structure which is the real seed without the fine coat. In some seeds this structure is wrinkled and with black color. These seeds are unable to germinate.

These flowers are variously colored, pink to reddish or light purple with white, contrasting markings, or white to cream or orange to red.

The South African species were originally pollinated by long-tongued anthrophorine bees, but some changes in the pollination system have occurred, allowing pollination by sunbirds, noctuid and sphingid moths, long-tongued flies and several others. In the temperate zones of Europe many of the hybrid large flowering sorts of gladiolas can be pollinated by small well-known wasps. Actually, They are not very good pollinators because of the large flowers of the plants and the small size of the wasps. Another insect in this zone which can try some of the nectar of the gladioli is the best-known European Hawk-moth Macroglossum stellatarum which usually pollinates many popular garden flowers like Petunia, Zinnia, Dianthus and others.

Gladioli are used as food plants by the larvae of some Lepidoptera species including the Large Yellow Underwing.

Gladioli have been extensively hybridized and a wide range of ornamental flower colours are available from the many varieties. The main hybrid groups have been obtained by crossing between four or five species, followed by selection: Grandiflorus, Primulines and Nanus. They make very good cut flowers. However, due to their height, the cultivated forms frequently tend to fall over in the wind if left on the plant.

The majority of the species in this genus are diploids with 30 chromosomes but the Grandiflora hybrids are tetraploids and possess 60 chromosomes. It's because the main parental species of these hybrids is Gladiolus dalenii which is also tetraploid and includes a wide range of varieties (like the Grandiflora hybrids).


Read about Gladiolus in the Standard Cyclopedia of Horticulture 

Gladiolus (diminutive of Latin gladius a sword, from the shape of the leaves. Popular summer- flowering and autumn-flowering bulbs, and now somewhat grown under glass.

Corm-bearing herbs with fls. in simple or branched spikes; lvs. radical and cauline: fl. more or less tubular, the tube usually funnel-shaped (enlarging upward); segms. 6, more or less unequal, strongly narrowed or even clawed at the base, the upper ones often hooded or roofed over the opening or mouth of the fl.; stamens 3, inserted on the tube: stigmas 3, on a long style; ovary 3-loculed, becoming an oblong 3-valved caps., with flattened and winged or sometimes globose seeds: each fl. is borne in a sessile spathe (like a calyx) with linear or lanceolate valves or lf.-like parts: the lvs. are mostly equitant on the st., all firm and prominently several-ribbed, varying from linear to sword-shaped (sometimes almost terete): the old conn dies and a new one grows on top, and cormels or offsets (sometimes called "spawn") form from the underpart (Fig. 1644).—The species of Gladiolus are 160 or more, perhaps 100 being in S. Afr. (Cape), many in Trop. Afr. in both the E. and the W., and others in the Medit. and W. Asian regions. The greater part of highly improved garden forms are derived more or less directly from the S. African species. The Eurasian species are little grown, although some of them are hardy. Gladioli have been much modified by variation, hybridizing and selection.

The gladiolus is propagated readily by seeds, as explained farther on; by the use of the new corm growing above the old one, and which is separated either when cleaning in autumn or before planting in spring; by the young corms, or cormels. Increasing stock by the small corms or cormels is the most common method, and the one by which a variety is perpetuated. The small corms are stored in bags, boxes or other suitable receptacles and kept from frost. It is a help to sprouting if the cormels are not allowed to dry out during the period of rest. They should be planted like one-year seedlings, and they give blooming plants the first and second year.

Great progress has been made in recent years in the improvement of the gladiolus, until in floriferousness, form color substance and keeping qualities it has become one of the important summer flowers, both for amateurs and florists. It is to be expected, however, that many other forms and qualities are yet to appear, considering the great number of wild species of much beauty that have not been combined in the cultivated strains. It may be possible, also, that closely related genera can be used to some extent in hybridizing. The lines of division between Gladiolus, Antholyza, Acidanthera, and some others, are more or less arbitrary.

The early departures were of the gandavensis (Fig. 1645) and similar types, founded probably on G. psiltacinus and G. cardinalis. Forms of G. tristis early entered into the cultivated strains, as well as G. oppositiflorus, and later G. purpureo-auratus and G. saundersii. The Lemoinei and nanceianus races (Fig. 1646) have afforded foundations for much subsequent breeding. Recently, G. primulinus has entered into the combinations. It seems to be particularly valuable as a parent; it is said to be dominant in color over even the deepest reds, subduing them to excellent shades of orange, salmon, and terra-cotta; when crossed with the lighter colors it transforms them to buff, lemon njid ecru; combined with yellow the color is deepened. The hooded character is commonly inherited. W. W. Van Fleet has succeeded in crossing this species with many of the other wild forms. With G. quartinianus the color is said to be toned down to terra-cotta and the season for blooming is changed from autumn to midsummer. When G. Watsonius is used, the progeny is tall, orange in color with scarlet veinings; the plants are earlier, more vigorous, and profuse bloomers. Hybrids from the above species, and from varieties of G. cardinalis produce tall graceful spikes of exquisite light tints.

The ruffled strains of gladioli have appeared in recent years, adding a pleasing variety and much merit to the flower. This type has been specially developed in the recent breeding work of A. E. Kunderd, of Goshen, Indiana (Fig. 1647). Nearly twenty years ago he began his selections for the production of a frilled or wavy flower, that should have something of the petal-edge exhibited so well in azalea. Early- and late-flowering strains have been produced. It is said that one strain has the blood of G. quartinianus and is producing many good shades of red with fluted or ruffled petals and suitable for late-flowering purposes. G. primulinus has also given good tints in yellows, with flowers very much frilled. It now seems possible to introduce the ruffling into many of the standard types, much as has been done with the sweet pea.

The recent Burbank strains have been developed from the variety America as the seed-parent. These are said to comprise many very large-flowered forms, with brilliant coloring.

The G. praecox group or strain was introduced by Frederick Roemer, of Quedlinburgh, Germany, said to be the result of intercrossing the earliest-flowering plants of G. gandavensis, G. lemoinei, G. childsii and G. nanceianus. In color, markings, or size, the race compares favorably with the parents, and at the same time the plants bloom the first year from seed, especially when the seed is started in a moderate hotbed in March. As growth advances, they are given ventilation gradually. There is a decided improvement the second year, when two or more spikes of normal size are usually produced. Other strains of gladiolus may also give bloom the first year from seed.

Some of the earlier history of American gladiolus- breeding was written for the "Cyclopedia of American Horticulture" by H. H. Groff, of Canada, one of the prominent contributors to the improvement of the flower (extracts): Some twenty-five years ago "when the writer, under the inspiration of Luther Burbank, began his own work in hybridization, the best American-grown stock available was the Hallock collection of some 400 named varieties of gandavensis and about 100 of the earlier Lemoine hybrids, all of European origin. After trial, the writer placed them all in mixtures. About this time Luther Burbank began to offer a few named varieties, but shortly afterward sold his whole stock, the collection being now in the writer's hands. This collection, in the opinion of the writer, is the best strain of gandavensis. The varieties were largely of variegated types, with many of unique markings and peculiar form. Burbank had given particular attention to varieties calculated to withstand the hot, dry winds of California, and had originated several with specially stiff petals, quite distinct from the ordinary types. The peculiarity of the flowers blooming around the spike like the hyacinth was also his contribution. All of his varieties are now grown in mixture by the writer with the exception of a white variety, which promises to be distinct and valuable for some time to come. The work of Van Fleet, of New Jersey, was carried on more for scientific than commercial results, and reaped a deserved success. However, the writer has found that the offspring of a pure species is less stable than that of well-balanced cross-bred varieties, the former system handing down few varieties of permanent commercial value, though they are in themselves valuable as parents for the foundation of new strains. The best work of a semi-professional character, in the opinion of the writer, has been done by T. S. Moore, of Indiana, who has spared no trouble or expense in procuring choice material upon which to build, and with satisfactory results." Writing in 1914, Groff speaks of the fluted, ruffled and crimped forms being frequent in the progeny of every improved species; of the development of iris-form flowers; and of innumerable influences, under breeding, on the character of the stalk, fiber, capsule, shape and size of foliage, disposition of flowers to droop or to grow erect, on the corm and its husk and the facility of producing cormels, and other interesting departures.

The interest in the gladiolus has been much stimulated in North America by the work of the American Gladiolus Society. It was organized at Boston, May 27, 1910, for the purpose of "stimulating interest in, and promoting the culture and development of the gladiolus; to establish a standard nomenclature; to test out new varieties, and to give them such recognition as they deserve; to study the diseases of the gladiolus, and find remedies for same; to disseminate information relating to this flower; to secure uniformity in awarding prizes at flower shows, and to give one exhibition each year." The society holds exhibitions, publishes a bulletin, and in many ways aids in the popularizing of the gladiolus and in establishing standards of excellence. It has a trial-ground at the New York State College of Agriculture at Cornell University, where gladioli are now being carefully studied. Following is a score-card prepared by direction of Gladiolus Society of Ohio:

TABLE

Culture of the gladiolus. (Isaac S. Hendrickson, except when otherwise stated.)

The Gladiolus has several good points combined to make it interesting, popular, and promising, as: The low cost; ease of culture; freedom from insects; variation in color; ease of carrying over from year to year; length of blooming season; rapid increase; ease with which new varieties are produced.

Figures recently compiled from information given by the growers in the United States are as follows:

Number of acres devoted to gladioli .............................. 400 to 500

Estimated number of bulbs produced annually.........14,000.000 to 15,000,000 Estimated value of crop ............................................ $250,000

Raising new varieties.

It is the contention of some growers that certain definite results can be secured by hand-crossing of different varieties, while other growers assert that they cannot trace a single valuable result to that method. The writer's observation has led him to the opinion that some of the best and most useful sorts on the market today are the results of careful selection of seed from the varieties showing best form, growth, color, vigor, size, and other qualities. It is well for the general gardener to purchase a collection of the best-named kinds now on sale, plant them together and let the insects transfer the pollen naturally; and if the weather is favorable, one is almost sure to have a crop of seed. This seed must be carried over until the following spring, when it can be planted in shallow drills, covering about one-eighth to one-fourth inch with soil; they will make only a slight grass-like growth the first year, and must be taken up in the fall, and housed away from frost. The following spring they can be planted as one would sow garden peas, and covered about 1 ½ inches deep; they will make a little more growth and perhaps a small percentage will flower, but the bulbs will have to be lifted and planted once more before a good showing of flowers can be expected. The commercial grower expects to wait three or four years after planting the seed before he has salable bulbs, which of course, can be sold only as seedlings or mixtures as all forms and colors will be present. In looking for new varieties to name, the greatest care must be taken to choose only those of real merit, something that is distinct from previous selections, new in color, good in substance, excellent in form, and in all ways meritorious. When the selection is finally made from perhaps thousands of seedlings, it is labeled out and lifted separately in the fall, and jealously guarded until the next planting-time; then it is watched with eagerness to see whether it will prove constant and worth taking the trouble to "bring up," for as it requires at least ten years to secure enough bulbs to offer for sale, one can easily waste much time if the selection does not prove to be a wise one. It is often said that there are too many varieties now under name, and this is true; but as it is so very easy and so fascinating to grow seedlings, one should not discourage the amateur in securing this satisfaction.

Of course the professional or expert breeder will exercise the most careful choice of the parent stocks; and he is able to make many interesting and valuable combinations of special qualities.

Culture.

While nearly any good garden soil is adapted to the culture of the gladiolus, the plant seems partial to a sandy loam. In field culture, gladioli are usually planted in rows similar to potatoes; that is to say, the furrows are made 3 feet apart to allow tillage with horse. The bulbs are placed in the row by hand, usually about 2 to 4 inches apart each way according to size, and covered about 4 or 5 inches deep. Deep planting prevents them blowing over. Frequent tillage must be given in spring and summer.

For garden culture, they may be planted promiscuously in the border if wanted for garden, decoration; or if wanted for cut-flowers principally, the straight-row method is best, as it enables better tillage to be given and makes it much easier to cut the blooms. The gladiolus is essentially a cut- flower. If one has a goodly number of bulbs, it is an excellent plan to make successive plantings about fifteen days apart, beginning as early as the ground can be worked and continued until July. This will insure continuous bloom from July until October, or until the plants are cut down by frost. As the old bulb or corm produces its flower, it dies and a new one forms in its place, and develops until harvest time, when it is lifted and stored in a warm dry place; some time during the winter the roots and old bulb should be taken off, so that the bulb will present a clean appearance and be ready for planting.

As a cut-flower, the gladiolus will rival most other flowers in keeping qualities. The blooms can be kept fresh and beautiful for a period of five to ten days after cutting by changing the water daily and removing each day the withered blooms; it also helps if the ends of the spike are nipped off when changing the water. If the spikes are cut when the first two or three flowers have opened, the entire stalk will open out after it has been put in water. They may be sent to a distance; they will arrive in excellent condition if a little care is taken when shipping. The spikes should be cut when the first flower opens, and put in water in the cellar or cool place for two or three hours, after which they will stand a journey of two or three days; and then when placed in water they will quickly respond and unfold their petals.

The uses of gladioli arc varied; great quantities are used for decorating dining tables in the great hotels and steamboats; florists have long recognized their value in making funeral designs; at the exhibition of the American Gladiolus Society, at Rochester, it was demonstrated that they can be used for fancy table decoration, wedding bouquets, and other purposes.

Varieties.

No two persons will agree on varieties, but the following represent some of the good types at present (given here as a matter of record):

White.—Europa, Blanche, Peace, LaLuna. Pink.— Wild Rose, America, Mrs. Frank Pendleton, Myrtle, Taconic, Panama. Scarlet.—Mrs. Francis King, Princeps, Brcnchleyensis, Contrast (scarlet and white). Yellow.—Golden King, Sulphur King, Niagara, Kun- derdi Glory. Maroon.—Empress of India, Mrs. Millins. Violet.—Baron Joseph Hulot.

Variation in size of bulbs.

There is great variation in size of bulb or corm. It is a varietal characteristic. Some kinds never make a large bulb; yet they may be superior kinds. This ought to give a hint in buying mixtures at the flower- shop. Nine times out of ten, when a customer has the opportunity to pick out the bulbs personally, the very largest ones are taken, with the result that perhaps not more than one or two kinds are received, as very often the very best and choicest flowers are concealed in the small or medium-sized corms. Some of the large-bulb sorts are very inferior, and it is easy to increase the stock, while others, perhaps producing smaller bottoms, bear only a few offsets.

Commercial cultivation for stock or bulbs. (E. H. Cushman.)

For successful commercial culture it is essential that sandy soil conditions are obtainable. Such preparation of the soil as puts it in a loose, friable condition will answer. Probably the ideal soil is a sod, fall-plowed and then most thoroughly worked in the spring. Strong, fresh stable manure should be avoided. If soil is not sufficiently rich in plant-food it is best to use all strong manures on a previous season's crop of some other kind. Any complete fertilizer is beneficial when thoroughly worked through the soil, at the rate of 600 to 1,000 pounds to the acre. Planting should be begun as early in the spring as the proper working of the soil will permit. The ground being prepared, it should be furrowed 4 inches deep and from 24 to 36 inches apart, according to method of cultivation. If fine, round bulbs are to be grown, and the stock for planting exceeds 1½ inches in diameter, it will be necessary to place the bulbs right side up in the furrow by hand, either in single or double rows 2 inches apart. Bulbs of lesser size may be scattered as evenly as possible along the furrow, with an average of ten or twelve to the foot of furrow. Clean culture throughout the growing season is essential. Cutting the spike of flowers is a help to increasing the size of the bulbs. Four months is sufficient for the growth and maturity of the bulb. To harvest, loosen the soil and lift the bulbs by their tops, and lay on the ground to dry off and ripen. Should weather permit, they can be entirely ripened out-of- doors. Cut the tops off close to the bulbs, pulling off the old bulbs and roots, and place in thin layers in crates and store in a cool, dry place. If circumstances require, the tops may be trimmed off at once on lifting. and the bulbs taken under cover for cleaning and drying.

Culture in California. (Sydney B. Mitchell.)

Gladioli, like all South African bulbs, do very well in California; indeed near Santa Cruz, some of the popular large-flowering varieties are grown in commercial quantities for their bulbs. These summer-flowering kinds may be planted in the fall to bloom in the following May and June, but in private gardens additional corms should be put in at intervals from April to July so that a succession of flowers may be available until October, right through the season when California gardens are barest. It should be noted that the early- flowering class of the nanus and Colvillei types are also quite hardy here and so do not require the glass protection given in the East. The favorite varieties of the nanus or dwarfs are Peach Blossom and Blushing Bride, while The Bride easily leads in the Colvillei section. A few of the less- known early species are also grown occasionally, as for example G. tristis (yellow and terracotta) and its variety concolor (pale greenish yellow), both of which flower in March around San Francisco Bay. The earlier-flowering classes should all be planted just as soon as available in late October or in November. Growth starts at once, but the flowers usually do not appear much before the following May, when they make a brave show and are fine for cutting. Their simple requirements are fall-planting in a well-drained, preferably loamy soil, put about 3 inches deep and about the same apart. Separate bulbs are reset each autumn for best results. As they increase quite rapidly and gain greatly in vigor after they have had a year in California, as far as soil and climate go, there is no good reason why the local-grown bulbs should not quite replace imported ones.

Indoor culture. (A. C. Hottes.)

Until recently, the gladiolus used for blooming indoors was principally of the nanus type. Planted in November, they bloom in April and May. They may first be started in 5-inch pots and later benched. They require a cool temperature, about 45° at night, if one expects the foliage to develop nicely. This is a temperature near that of the carnation optimum; they are therefore, often planted around the margins of the carnation benches. Their growth at first is slow, making little growth till the sun gets higher in the spring.

The flowers of the nanus type appear two or three weeks earlier than the standard varieties of gandavensis, lemoinei or nanceianus. Varieties of the latter groups, however, are being developed with the desirable qualities for forcing, that of earliness and of a pleasing commercial color, and are becoming of considerable importance as a spring flower for the florist.

If the stems are not cut too short, the corms will renew themselves as well as in outdoor culture and they can be forced again or given a year's growth in the field.

The kinds of gladiolus.

The following account includes those species that appear to have any particular horticultural history; also some of the prominent Latin-named hybrids, although not all these hybrids may now be in commerce.

Index. adlami, 20. alatus, 2. albidus, 24. albus, 28. augustus, 5. atroviolaceus, 7. biflorus, 8. blandus, 24. brenchleyensis, 20. brinerii, 33. byzantinus, 11. cardinalis, 15. carneus, 10, 24. childsii, 32. citrinus, 29. colvillei, 28. communis, 10. concolor, 4, 19. cordatus, 5. crispiflorus, 6. cruentus, 16. delicatissimus, 28. dracocephalus, 21. engesseri, 33. erectus, 19. excelsus, 24. fasciatus, 9. floribundus, 25, 28. froebelii, 33. gandavensis, 29. grandis, 3. hibbertii, 24. hollandia, 29. hybridus, 35. imbricatus, 6. kunderdii, 37. leichtlinii, 14. lemoinei, 30. maculatus, 19. major, 10. milleri, 27. mortonius, 24. namaquensis, 2. nanceianus, 31. nanus, 28. natalensis, 22. oppositiflorus, 26. papilio, 13. praecox, 36. primulinus, 19. princeps, 35. psittacinus, 22. purpureo-auratus, 23. quartinianus, 18. ramosus. 28. salmoneus, 19. saundersii, 17. segetum, 12. sulphureus, 20. superbus, 17. trimaculatus, 5. tristis, 4. turicensis, 34. undulatus, 9. versicolor, 3. vinulus, 9. vittatus, 9. watsonius, 1.

I. Species Of Gladiolus (Nos. 1-27). Few of the original species of Gladiolus are in cultivation in their pure form. When grown at all, they are prized chiefly as oddities, or because of their botanical interest.

Many species of Gladiolus are likely to be discussed in horticultural literature. The following have recently been prominently mentioned: G. carmineus, C. Hi Wright. Resembles R. ramosus, Paxt., but differs in its laxer habit, longer spathc and yellow anthers: slender, 1 ½ ft.: lvs. linear, acuminate, 8 in. long and ½ in. broad: fls. carmine, about 3 in. across; tube narrow-funnel-shaped, white outride; segms. ovate, acuminate, 2 of the inner bearing a dark spot with a pale center; stamens rather more than half length of perianth. 8. Afr. B.M. 8068.—G. glaucus. Heldr. Dwarf, not exceeding 12 in.: st. and lvs. erect and stiff: fls. many, bluish red with red and white stripes at bane. Greece.—G. mackinderi, Hook, f. St. slender, 2 ft.: lvs. narrowly linear, the lower about 1 ft. long: fls. 5-6, the tube yellow, broad segms. scarlet and 1 ½ in. across. E. Trop. Afr. B.M. 7800. Named for Professor Mackinder, Oxford, who collected seeds at 10,000 ft. on Ml. Kenia in 1900. One of the Homoglossum section. CH


The above text is from the Standard Cyclopedia of Horticulture. It may be out of date, but still contains valuable and interesting information which can be incorporated into the remainder of the article. Click on "Collapse" in the header to hide this text.


Cultivation

In temperate zones, the corms of most species and hybrids should be lifted in autumn and stored over winter in a frost-free place, then replanted in spring. Some species from Europe and high altitudes in Africa, as well as the small 'Nanus' hybrids, are much hardier (to at least -15°F/-26°C) and can be left in the ground in regions with sufficiently dry winters. Plants are propagated either from small cormlets produced as offsets by the parent corms, or from seed; in either case, they take several years to get to flowering size. Clumps should be dug up and divided every few years to keep them vigorous.

Propagation

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Pests and diseases

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Species

Species

 
Gladiolus alatus, Clanwilliam, RSA
 
Gladiolus cardinalis
from Curtis's Botanical Magazine 1790
 
Waved-flowered Gladiolus (Gladiolus undulatus)
from Curtis's Botanical Magazine 1801
 
Gladiolus hybrid, Grandiflorus group
 
A Gladiolus hybrid

The genus Gladiolus has been divided in to many sections. Where possible, the sections have been indicated. Most species, however, are only tentatively placed.

Gallery

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References

External links


  1. Manning, John; Goldblatt, Peter (2008). The Iris Family: Natural History & Classification. Portland, Oregon: Timber Press. pp. 138–42. ISBN 0-88192-897-6.