1919] Hall-Goodspeed; Chrysil 193 



dull green as in viridulus, or gray as in gnaphalodes. In typical 

 nauseosus and in hololeuciis the foliage is entirely covered by a beauti- 

 ful soft and white woolly tomentum. 



The flowers are yellow, very showy, and grow in heads arranged 

 in dome-shaped to oblong clusters terminating the stems. The plants 

 are therefore highly ornamental during the flowering season, which 

 extends from August to October. At that time the large round-topped 

 shrubs are crowned with a profusion of golden-yellow flower- 

 clusters. As winter advances the flowers wither and fall, the foliage 

 becomes more and more sparse, and finally only the naked gray or 

 dull green twigs and empty involucres remain. The young twigs then 

 die back for a considerable distance. But soon after the first winter 

 rains or snows new shoots, springing from lateral buds well down on 

 the year-old wood, form a new top to the plant. Since the die-back 

 of the annual shoots does not extend to the base the general height, or 

 level, of the old wood is increased each year. At the same time there 

 is a thickening of all of the older stems through the addition of another 

 annual layer of wood. The flowers of Chrysothamnus, which are very 

 small and assembled into heads, as in all the Compositae, are much 

 visited by honey bees and other insects. This assures cross-pollination 

 and there is no evidence that the flowers are self-fertile. Seeds are 

 set in abundance, and they show a high percentage of viability. These 

 characters enable the plants to occupy quickly any suitable area that 

 has been cleared of other brush. 



The herbage of Chrysothamnus possesses a peculiar odor v/hich 

 varies somewhat with the different forms. The name nauseosus indi- 

 cates that the type of that species was disagreeably scented but this 

 we have not been able to verify. In viridulus, however, the green 

 stems when broken emit a very strong, disagreeable odor, especially 

 penetrating if they are burned in a closed room. On the other hand, 

 when the twigs and foliage of gnaphalodes and hololeucus are broken 

 in the hand the odor is exceedingly pleasant, suggesting a combina- 

 tion of tropical fruits and berries. It seems probable that this is due 

 to the presence of a volatile oil which might have commercial possi- 

 bilities if properly exploited, more especially as a by-product in case 

 the plants are brought under cultivation for their Chrysil. 



The age of full-sized shrubs is quite variable, depending upon the 

 conditions under which the shrubs have grown and also possibly upon 

 the botanical variety concerned. An estimate based upon counts of 

 annual rings, places the average age of the more important kinds. 



