Helianthus
(from helios, the sun, and anthos, a flower). Sunflower. Including Harpalium. ORD. Compositae. A genus containing about fifty species of tall, hardy, annual or perennial herbs, natives, for the most part, of North America; a few, however, are found in Peru and Chili. Flower-heads very large; ray-florets yellow; disk-florets purple or violet. Leaves large, simple, scabrid. All the species are of easy culture in almost any moderately good garden soil. The taller-growing ones are best adapted for growing in a shrubbery, or in the back rows of herbaceous borders, where they will require plenty of space to fully develop. Propagated by divisions; or by seeds, sown either in pots, and the seedlings afterwards transplanted, or in the open ground, about March.
H. angustifolius (narrow-leaved). fl.-heads about 1 1/2in. across, numerously disposed in a long, leafy raceme. September and October. l. dark green, narrow, tufted, glossy. Stems slender. h. 2 1/2ft. Perennial.
H. annuus (annual).* Common Sunflower. fl.-heads very large, varying in size and colour. Summer. h. 6ft. Western United States, 1596. (B. M. 2051.) Of the many varieties of this annual species, the finest is globosus fistulosus the flowers of which are very large, and of a splendid, extremely double, globular form, when fully developed. It is best grown in a rich, deep soil. Other forms are: californicus plenissimus cucumerifolius, giganteus, and grandiflorus.
H. a. macrocarpus (large-fruited). A cultivated race, with larger and lighter-coloured achenes, long cultivated in Russia, &c., for food and oil.
H. argophyllus (silver-leaved). fl.-heads yellow. Autumn. l. clothed with a soft, silky, silvery down. h. 6ft. Texas. This species is closely allied to H. annuus, into which it appears to degenerate under cultivation. Annual.
H. atrorubens (dark-red). fl.-heads scattered; disk dark red or purple; rays yellow, acuminated, entire. l., radical ones flat, hairy; upper ones twisted and waved, hairy, tuberculated. Stems purple, rough, with whitish hairs. h. 2ft. to 3ft. United states, 1732. Perennial.
H. decapetalus (ten-petaled). fl.-heads about 2in. across, terminal, solitary, on slender, twiggy branchlets. Autumn. l., lower ones somewhat ovate-acuminate, hardly 6in. long; upper ones 2in. to 3in. long; all somewhat obscurely serrate. h. 5ft. Perennial. (B. M. 3510.)
H. d. multiflorus (many-flowered).* This is a very old garden plant, only known in cultivation. It has firmer leaves, larger heads, and more numerous bracts than decapetalus. (B. M. 227, under name of H. multiflorus.) The common form is of dwarf habit, with double flowers.
H. d. multiflorus major only differs from ordinary multiflorus in its larger flower-heads.
H. diffusus (diffuse). A synonym of H. rigidus.
H. lenticularis (lenticular). fl.-heads yellow, large, drooping; scale of involucre expanded, scabrous on the back. August. l. alternate, petiolate, ovate, three-nerved, serrate. Stem hispid. h. 6ft. North America, 1827. (B. R. 1265.) This is a variety of the Common Sunflower, H. annuus.
H. mollis (soft). fl.-heads yellow. July to October. l. ovate, acuminate, three-nerved, closely-serrated, scabrous above, hoary and soft beneath. h. 4ft. North America, 1805. (B. M. 3689.)
H. orgyalis (6ft. high).* fl.-heads yellow, comparatively small, numerous, forming a large panicle. Autumn. l. alternate, numerous, very narrow and recurved, 5in. to 8in. long, 1/2in. to 1in. wide. h. 6ft. to 10ft. United States, 1879. Very graceful, and one of the best and most useful decorative autumnal-flowering plants. Perennial.
H. pubescens (downy). See Wyethia angustifolia.
H. rigidus (rigid).* fl.-heads glistening golden-yellow, about 4in. across, formed of a deep ray and small disk; ray-florets 1 1/2in. long. 1/2in. broad, tips incurved, and edges reflexed; disk-florets chocolate colour; involucre scaly; peduncles long, hairy. August. l., stem ones very hispid, lanceolate, slightly dentate; radical ones few, oval, 5in. or 6in. long. h. 3ft. North America. Perennial. SYN. H. diffusus. (B. M. 2020.)
H. tuberosus (tuberous). Jerusalem Artichoke. fl.-heads yellow. September and October. l. three-nerved, scabrous; lower cordate-ovate, upper ovate-acuminate, alternate; petioles ciliated at base. Roots creeping, and towards the end of autumn produce a number of round, irregular, reddish or yellow tubers, clustered together, and of about the size of an ordinary potato. h. 6ft. to 8ft. Upper Canada and United States, 1617. This was cultivated by the aborigines, and the tubers developed. It is certainly not South American, as stated in so many books. The common name of this species is supposed to be a corruption of the Italian Girasole articocco, or Sunflower Artichoke. For culture, see Artichoke, Jerusalem.