Helianthus


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Read about Helianthus in the Standard Cyclopedia of Horticulture 

Helianthus (Greek, helios, the sun, and anthos, a flower). Compositae. Including Harpalium. Sun- Flower. Hardy herbaceous perennial and annual plants, rather coarse in habit, with yellow flowers which are mostly large, numerous and borne in autumn.

Leaves generally opposite below and alternate above, but this is not a constant character: heads pedunculate, solitary or corymbose, terminating the st. or branches; disk-fls. perfect, yellow, brown or purplish, with a tubular 5-limbed corolla; rays neutral, yellow.—Altogether there are about 60 species, mostly N. American, and many of the plants grown for sunflowers are now considered as belonging to other genera. The genus is very variable, and there are also many natural hybrids; hence the species are difficult to delimit. The old notion that the flower-heads follow the sun from east to west has been substantiated for H. annuus. (See Botanical Gazette, vol. 29:197.) Garden monographs are found in Gn. 27, p. 66; 45, p. 372; 49, p. 326 and 55, p. 146.

Sunflowers are of the easiest culture, and are adapted to a variety of soils. They are seen to best advantage when planted in masses, rather than as solitary specimens, and should be given plenty of room, being gross feeders. Most sunflowers, especially H. annuus, are too coarse to be harmonious near the house, but find an effective setting in the background, against the shrubbery border. A few species, however, especially H. orgyalis and H. debilis, are worth growing for their foliage alone. The annual species are propagated by seeds or cuttings: the perennial chiefly by division. All varieties of H. multiflorus root readily from both soft and hardwood cuttings. The double forms rarely produce fertile seeds and must be propagated by division. The seeds of annuals may be planted directly in the border, but it is best to start them indoors in March. Perennial kinds, particularly forms of H. multiflorus, should be taken up in late fall or early spring, every two years, and the roptstocks divided and replanted; otherwise the roots will ramble away, and the flowers will deteriorate. All thrive in a light, dry soil; but H. annuus and H. giganteus may be used to advantage for drying malarial spots. Sunflowers do not thrive in very shady places.

Commercial, uses and cultivation of the common sunflower. (M. G. Kains).

Sunflowers (H. annuus) are cultivated extensively in Russia, India and Egypt; less widely in Turkey, Germany, Italy and France. The seeds from the large- seeded variety are sold upon the streets in Russia as we do peanuts, except that they are eaten raw. The small- seeded variety is preferred for the manufacture of oil. When cold-pressed, a citron-yellow sweet-tasting oil, considered equal to olive or almond oil for table use, is produced. The resulting oil-cake, when warm-pressed, yields a less edible fluid, which is used for lighting, and in such arts as woollen dressing, candle- and soap-making. The oils dry slowly, become turbid at ordinary temperatures and solid at 4° F. For stock and poultry feeding, and for other purposes, sunflower oil-cake is about equal in value to that of flax- and cotton-seed. The cake is largely exported by Russia to Denmark and Sweden, and to some extent to other European markets. Sunflower stems and heads make an excellent paper, and the stems furnish a fine fiber that compares favorably with silk. They are, however, generally used for fuel, since the above industries have not been developed. —Sunflowers grow readily in many soils, but best results are secured upon light, rich, calcareous or alluvial land, well supplied with moisture and unshaded by trees. White, clayey and poor soils are unfavorable. Preparation of the soil should be thorough, deep fall plowing followed by spring harrowing being preferred to spring preparation. The seeds are generally sown in drills running north and south, 30 inches apart, 9 inches asunder in the drill, and 1 inch deep. Sometimes they are transplanted from nursery beds when 4 to 6 inches tall. About a week after the plants appear they are thinned to 18 inches apart. From four to six pounds of the seed will sow an acre. Cultivation is the same as for corn, except that when the plants reach a height of 3 to 4 feet, the inferior flower-heads should be removed, leaving only four or five on the principal stem. In windy climates hilling is sometimes necessary to prevent blowing down.—On some farms the heads are harvested as they ripen and placed upon floors or movable pole-racks to dry. Upon larger areas they are cut to the ground when most of the heads have ripened and piled, heads up, to cure. The former method insures a much higher grade of oil, and is therefore preferred. Every effort is made to prevent fermentation, either in the heads or in the pile of seeds, since this injures the quality of the oil. When thoroughly dry the heads are either placed on racks or piled, face downward, on a floor and beaten with flails. The seeds are then spread thinly, shoveled over occasionally, and allowed to become perfectly dry before being sent to the mill. The average yield is about fifty bushels to the acre. The percentage of husks ranges from 40 to 60; and the oil from 15 to 28. As a general rule, 100 bushels of seed will yield 33 bushels of kernels, 100 bushels of kernels from 280 to 320 gallons of oil of both qualities. Russian sunflower, a large-seeded variety, producing a single head, grows 8 feet tall, but is less esteemed for oil-production than the small-seeded varieties. In America the sunflower industry is small.

The red sunflower. (T. D. A. Cockerel.)

In the summer of 1910 Mrs. Cockerell found a red sunflower growing by the roadside close to her home at Boulder, Colorado. It was a variation of the native sunflower of the plains (Helianlhus annuus var. lenticularis, or H. lenticularis), having the rays suffused with chestnut-red. It was named var. coronatus, the arrangement of the red, with the black disk, suggesting the sun in eclipse, with its corona. Since the sunflower is sterile with its own pollen, it was necessary to cross the red one with yellow-rayed kinds, such as the garden H. annuus, and the yellow-rayed wild plant. The next summer, it was found that about half the progeny had red rays: it was determined that red was dominant, and assumed that the plant originally found was heterozygous for red, through variation occurring in a germ- cell. Crossing red with red, homozygous or pure-bred reds were obtained, with very rich colors. Most sunflowers carry a factor for marking, which affects the distribution of red, so that many of the flowers were bicolored with the ends of the rays yellow (var. tricolor) while others had a ring of red (var. zonatus). Some had the rays entirely chestnut-red (var. ruberrimus). A variety obtained in 1914 had the rays practically black. So far, the red of the red sunflowers was a chestnut, or brown-red. The pigment, however, belongs to the anthocyan group, and is chestnut only because seen on a background of orange. In order to obtain a new color, the homozygous red was crossed with Button's primrose variety (var. primulinus, Ckll., "Science," August 29, 1913, page 312). In the first generation (raised in the greenhouse during the winter) the flowers were all red on orange, or chestnut-red. These crossed together gave seventy-one chestnut-red, nineteen yellow, twenty-five wine-red and eight primrose; theoretical expectation, according to Mendel's law. being sixty-nine, twenty-three, twenty-three, and eight. The wine-red is due to the same anthocyan pigment, but on a primrose-yellow (pale yellow) background. In good examples, the color is nearly that known as "old rose." The various patterns are as in the chestnut-red forms. The wine-red sunflower was named var. vinosus. In addition to the above, various other varieties have been developed, including red and wine-red semi-doubles and doubles. There are also hybrids with Helianthus cucumerifolius, of relatively small stature and with shiny foliage. One of these hybrids, represented in the 1914 cultures by a number of plants, may be described as follows: About 4 feet high, spreading, much branched: stems speckled with purple: leaves dark green, very shiny; blades broad and short, strongly dentate: involucral bracts with long tapering ends (but not so long as in true H. cucumerifolius); disk small (about 1 inch diameter); rays ample, broad, numerous, with basal half rich chestnut, apical half bright lemon; disk very dark. This is a plant of the second generation from the original cross. For further details see "Popular Science Monthly," April 1912; "Science," August 29, 1913, pages 312, 313; August 21, 1914, pages 283-285, November 13, 1914, pages 708, 709 and January 1, 1915, pages 33, 34. "Garden Magazine," July, 1914. The red sunflower is now offered by the trade in America, England, Germany and Italy. It has also been grown successfully in Australia and New Zealand.

Index. aestivalis, 6. grandiflorus, 6, 11. pumilus, 18. angustifolius, 5. groese-serratus, 9. purpureus, 3. annuus, 1. hirsutus, 21. rigidis. 6. argophyllus, 2. laetiflorus, 20. ruberrimus, 1. atrorubens, 7. laevigatus, 8. scaberrimus, 6. tricolor, 1, lenticularis, 1. sparsifolius, 7. californicus, 1, 19. macrophyllus, 10. semi-plenus, 6, 20. citrinus, 1, major, 11. simplex, 11. cordatus, 17. maximilianii, 14. strumosus, 10. cucumerifolius, 3. maximus, 11. subtuberosus, 13. debilis. 3. missouriensis, 6. texana, 2. decapetalus, 11. mollis, 17. trachelifolius, 22. divaricatus, 12. multiflorus, 11. tuberosus, 15. doronicoides, 16. nanus, 1. variegatus, 1. duplex, 11. niger, 1. vinosissimus, 1. flore-pleno, 11. orgyalis, 4. vinosus, 1. giganteus, 13. plumosus, 3. zonatus, 1. globosus, 1. primulinus, 1.

H. ciliaris, DC. Fl.-head large; rays bright golden-yellow; disk-florets dark brown. A pretty floriferous species. Texas, Ariz., Mex.—H. coloradensis, Ckll. Allied to H. fascicularis and H. grosse-serratus: 6 ft., in clumps: sts. strict, reddish and glaucous: lvs. elongate-lanceolate, rough, margins remotely dentate, the upper ones alternate and the lower opposite: bracts of involucre very long and slender, long-ciliate at base: disk yellow, and rays bright orange. Colorado. Var. Andrewsii, Ckll. Rays deep orange, much richer in color.—H. macrophyllus satitus of horticultural literature, with tubers edible and in taste resembling Jerusalem artichoke, is probably H. strumosus var. macrophyllus, Britt., or possibly H. giganteus var. subtorosus, Britt. There are many forms of wild sunflower that may come into cult., through dealers in native plants. These should be sought in the regular manuals of botany. The genus allows of different botanical interpretations.

S. W. Fletcher. N.Taylor.


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.


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