SUPPLEMENT 



which has inconspicuous flowers, is an introduced European weed; 

 and the handsome, shrubby, autumn-blooming Senecio Douglasii, 

 is described in the Supplement to Chapter III. There are other 

 Baerias difficult of identification, and two very large flowered species 

 of lyeptosyne are occasionally met on the sea coast or desert. The 

 Leptosynes can be recognised by the characteristic double involucre 

 described in Chapter IX, Supplement. 



The genus Bidens, including the bur-marigold, B. chrysanthemoides, 

 Michx., and the Spanish needle, B. pilosa, Linn., is another genus 

 belonging to the sunflower tribe, and the large flowers of the former 

 species, so abundant along streams in autumn, much resemble sun- 

 flowers. The akenes of both species are tipped with from two to four 

 barbed awns, which are most efficient in distributing the seed. The 

 species B. pilosa is an introduced weed common in waste places in 

 the south; neither foliage nor flower is attractive, and the fruits are a 

 great affliction to pedestrians. 



The two tar- weed, genera, Madia and Hemizonia, also belong to 

 this tribe. They are taken up in the Reader in Chapter XVI, but as 

 some of them bloom in May, it may be best to consider the genera 

 here. The name Hemizonia was suggested by the shape of the invo- 

 lucre, which, in both genera, is hemispherical. The bracts of the 

 involucre, in both genera, infold the akenes of the ray flowers. 

 Madia sativa, Molina, blooming in July and August, is probably the 

 most obnoxious of all this obnoxious tribe ; it is unattractive and 

 ill scented, and its resinous secretion mingled with dust ruins clothing; 

 but this same secretion, besides protecting the plant in several ways, 

 fastens the bracts containing ripened fruits to passing objects. 

 Another Madia, M. elegans, Don., blooming in May and June, is fra- 

 grant, and has handsome flower heads that close during the heat of 

 the day ; the yellow ray flowers are often marked with brown or dark 

 red at the base, suggesting the name wild coreopsis. These and other 

 Madias are much more common northward than in the south ; so are 

 the Hemizonias generally, excepting H.fasciculata var. ramosissima, 

 Gray, which begins blooming in June and becomes a common feature 

 of summer vegetation. This plant is low but much branched ; it has 

 sparse foliage, and very numerous small flower heads, though with 

 five broad, yellow ray flowers each. The species//, pungens, T. &G., 

 has leaves and bracts tipped with spines. H. luzulce folia, DC., is the 

 most common species in the more northern harvest fields ; it has a 

 spicy odor and rather attractive white or pale yellow flower heads of 

 medium size. John Muir devotes a page of his " Mountains of Cali- 

 fornia ' ' to the charms of another Hemizonia, which blooms in Octo- 



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