314 3 FLOWERS OF GARDEN AND GREENHOUSE 
habit, with very narrow leaves, the margins more nearly parallel, and 
flesh-coloured flowers; June. They are grown from seeds as half-hardy 
annuals, sowing in April, and planting out in June. 
- HELENIUM (the old Greek name). A genus of about eighteen species 
of hardy herbs, with alternate leaves and large yellow heads, natives of 
Central and North America. Several Species are in cultivation; chief 
among them is Heleniwm autumnale, growing to a height of 5 or 6 
feet, with lance-shaped leaves and large heads of pure yellow; August 
to October. A strong-growing, showy perennial, introduced from North 
America (1729). H. Bolanderi is a Californian perennial of dwarf habit, 
with large yellow heads. ZH. Hoopesii is about 24 feet high, with lance- 
shaped, stem-clasping leaves, and bright orange heads 2 inches across; 
June to September. Hardy perennial, H. nudiflorum grows 2 or 3 feet 
high, with slender lance-shaped leaves, and fragrant heads of pure 
yellow; July to October. This also is a perennial, and there is a variety 
of it (var. atropurpurewm) with purple ray-florets. H. tenuifoliwm 
to about 18 inches high. Perennial. These plants are all of vigorous 
habit, strong-growing, and requiring space, which will be best found in 
the shrubbery border. The freely-produced large flower-heads are 
useful for cutting. Propagation by division of the roots and sowing 
seeds. 
DiMorPHOTHECA (Greek, dimorphe, two forms, and theka, a recep- 
_tacle; two forms of disk-florets). A genus of about twenty half-hardy 
South African herbs and shrubs. They are very similar to the genus 
Calendula, from which they differ chiefly in the seeds being straight 
Cape Marigold, an annual, growing to a height of about a foot, with weak 
stems, narrow leaves and flower-heads 2 to 3 inches across. The disk is 
brown, the ray-florets white above and violet beneath. A singular effect 
1s produced on the approach of rain, for the ray-florets close over the 
disk, and what was a clump of white and brown flowers a few minutes 
previously, now appear to have changed to violet. These heads are out 
from June to September. The seeds should be sown in heat in March, 
and planted out in well-drained loamy soil about May. 
ONOPORDON (the old Greek hame, used by Pliny). Cotton Thistles. 
A genus of hardy herbs, with pinnately-cut or wavy-toothed leaves con- 
“pti down the winged-stem where this is present, and large heads of 
Owers with many leathery, spiny bracts. They are natives of Europe, 
