PLANTS OF BERMUDA. 43 



lobes very irregular, acute, sub-entire ; uppermost linear entire ; 

 heads numerous, in spreading panicles ; outer bracts five, ovate, 

 covering the inner orbicular ones and supporting the five distant 

 fertile florets ; acheniafive, compressed. Distribution, West Indies ; 

 habitat, waysides and waste places, common. Heads quarter-inch, 

 white ; summer months. 



X. AMBROSIA. 



Annual weeds, %vith plnnatijld leaves and inconspicuous flowers. Barren 

 heads, many -flowered in slender racemes ; fertile flowers solitary at base of 

 racemes or in axils of upper leaves ; involucre entire or flve-toothed, one- 

 flowered. 



1. A. artemisifolia (Hogweed). Stem stout, erect, one to three 

 feet high, branched, pubescent ; petioles fringed with slender hairs ; 

 leaves twice pinnatifid, segments acute, few -toothed ; racemes 

 slender, terminal, the heads barren and surrounded by united scales ; 

 fertile involucre armed with five to six teeth, one-flowered ; corolla 

 and stamens none. Distribution, North America and West Indies ; 

 habitat, waysides and cultivated ground. Beads very small, green- 

 ish with yellow stamens ; May to September. 



XI. BIDENS. 



Anmtal plants, with opposite leaves ; heads radiate, rays barren ; Invol- 

 ucre two- seriate ; achenium four-angled, crowned by two persistent, 

 barbed awns. 



1. B. leucanthus (Shepherd's needle). An erect, annual herb; 

 stems branching, four- angular, nearly smooth ; leaves pinnate 

 (rarely simple), consisting of three to five ovate, coarsely- serrated 

 leaflets ; heads in corymbs ; outer scales of involucre leafy, spread- 

 ing, inner membranous, appressed ; ray florets five to eight, large 

 white entire or three -lobed ; disk yellow ; achenia slender, half -inch 

 long, with two to four arms. Distribution, tropical countries ; habit- 

 at, a very common weed, and troublesome from the barbed awns 

 sticking to the clothes of the passer-by. Heads three-quarters an 

 inch in diameter ; summer months. 



XII. GNAPHALIUM. 



Herbaceous plants, usually clothed ivith woolly hairs ; heads small, 

 bracts half transparent, florets all tubular, outer atvl-shaped, female, cen- 

 tral florets five-toothed, perfect ; pappus hairs in one series, rough. 



1. G. luteo-album (Everlastings). A small, annual plant, with 

 spreading, decumbent stems two to four inches long, white, with 

 woolly hairs ; leaves one to one and a half inches, narrow, oblong, 

 acute, half embracing the stem, margin wavy ; receptacle depressed, 

 bracts silvery. Distribution, most warm countries ; habitat, sandy 

 waysides, occasional. Heads pale yellow, glistening, one -eighth to 

 one-quarter of an inch in diameter ; May to July. 



