274 FLOWERS OF GARDEN AND GREENHOUSE 
with silvery down, shrubby, 1 foot high. Leaves very slender, 
stalkless, silvery beneath. Flower-heads yellow, in crowded corymbs ; 
June to August. 
Helichryswms are propagated by seeds, cuttings, or 
division, according to the duration of the species, whether 
annual or perennial, The annuals should be sown in the open border at 
the beginning of April, and the seedlings thinned out or pricked out in 
May at a distance of about a foot apart. A light though rich loamy soil 
suits them best Cuttings of the perennials should be taken in spring 
and inserted in a close, almost cool frame. 
Description of Helichrysum bracteatwm and varieties. An enlarged 
Plate 137. section of the flower-head is shown at 1; Fig. 2 is a single 
bract; 3, a floret with its pappus ; Fig. 4, the fruit, natural size and 
enlarged ; 5, a seedling. 
Cultivation. 
COMPASS-PLANTS 
Natural Order Composira. Genus Silphiwm 
SILPHIUM (from Silphion, a classical Greek plant name). A genus of - 
about a dozen perennial herbs which exude a resinous juice. The leaves 
are large, toothed, lobed, or almost entire. The flower-heads are always” 
yellow ; the ray-florets strap-shaped, female; disk-florets tubular, male 
The fruits are smooth, surrounded by a wing, which is notched at the 
top. The species are restricted to North America. 
History. With a few exceptions, Silphiums can only be regarded 
as weeds in their native habitat. Most of the species 
have been introduced, but with one exception they are scarcely ever 
grown. The exception is Silphium laciniatum, the so-called Compass- 
Plant, Polar-plant, or Pilot-weed, which grows upon wide, open prairies, 
and is reputed to hold its leaves erect in such manner that the two faces 
: always look north and south, and so serve the purpose of a compass to 
the wanderer. The y ounger specimens are said to do this more 
effectually than the fully-grown ones; but the evidence of certain 
travellers has gone to discredit these statements by contending that the 
leaves cannot be at all relied upon to perform the function ascribed to 
them, Our readers who may grow this species will perhaps » 
interested in carefully observing the attitude of the leaves, and noting 
how far the popular name is deserved. It was introduced from North 
America in 1781, 
