236 Conmposita—Solidago. 
few, uniseriate. Pappus in one series of rigid scabrid bristles. 
The name is unexplained. S. Virgairea, Golden Rod, is a 
native representative of this genus; but some of the North 
American species are more ornamental, as S. Canadénsts, S. 
levigata, S. rigida, and S. altissima, all tall-growing plants 
and only admissible in shrubberies and by-places. 
Linosyris vulgaris, Goldilocks, is a rare indigenous plant of 
close affinity. It grows about 18 inches high, and is densely 
clothed with linear glabrous entire leaves. Flower-heads small, 
corymbose ; florets all tubular, 5-cleft, yellow. 
12. BACCHARIS. 
A very large genus of American plants, containing many 
shrubby and arborescent species of very diverse habit, readily 
distinguished from allied genera by their dicecious flowers. 
Although there are some 200 species, only one is in general 
cultivation. Many of the species are resinous and strongly 
scented, and this name, of Greek origin, was applied to some 
resinous shrub. 
1. B. halimifolia. Groundsel Tree.—A shrub from 6 to 12 
feet high with angular branches and obovate or oblong-cuneate 
coarsely-toothed scurfy leaves very much resembling those of 
some Chenopodiacece. Flower-heads small, yellow. The female 
is the handsomer plant of the two, from its conspicuous silvery 
pappus. This flourishes near the sea. 
13. DAHLIA. 
This popular genus is eharacterised by having a double 
involucre, no pappus, and a large scarious bracteole at the base 
of each floret. It was named in honour of a Swedish botanist 
named Dahl, and contains probably not more than half a dozen 
species, all of which are natives of Mexico. 
1. D. varidbilis. Common Dahlia.—This appears to be a 
variable plant in nature, and has received several names sup- 
posed to indicate distinct species, but they are now generally 
united under the above designation. There were two tolerably 
distinct forms originally introduced : one, frustramea, in which 
the outer involncral bracts are spreading; and the other, swpér- 
flua, having them reflexed and also producing seed more freely. 
The latter variety was introduced into this country as early 
as 1789 by the Marchioness of Bute, but soon lost, and not 
