236 • THE COMPOSITE FAMILY. [Bidens. 



In wet ditches and marshes, throughout the temperate and northern 

 regions of Europe, Asia, and America. Common in England and 

 southern Scotland. FL summer and autumn. 



2. B. tripartita, Linn. (fig. 522). Three-cleft #— Only differs from 

 B. cernua in the leaves, which are deeply cut into 3 or 5 lanceolate 

 segments, and in the flower-heads rather less drooping. 



Its geographical range and stations are the same as those of B. cernua, 

 but is rather less common in Britain. FL summer and autumn. 



XII. CHRYSANTHEMUM. CHRYSANTHEMUM. 



Annual or perennial herbs (or, in some exotic species, shrubs), with 

 alternate toothed or variously dissected leaves, and radiating flower- 

 heads, solitary on terminal peduncles, or in corymbs. Involucres 

 hemispherical, with a few rows of imbricate bracts, more or less 

 scarious on the edges. Receptacle flat or convex, without scales. 

 Achenes angular or striate, without any pappus, but sometimes crowned 

 with a minute raised border. Style nearly that of Senecio. 



A considerable genus, extending over Europe, northern and central 

 Asia, and northern Africa. It has been divided by modern botanists 

 into a number of small genera, founded upon minute, almost micro- 

 scopical characters, having little relation to general habit. Among 

 them Pyrethrum has been the most generally adopted, although botanists 

 are but little agreed as to the characters or species which should be 

 assigned to it. 



Ray yellow 2. (7. segetum. 



Ray white. 



Leaves toothed only 1. C. Leucanthemum. 



Leaves pinnate. 

 Flower-heads in corymbs. Segments of the leaves 



pinnatifid and toothed 3. C. Parthenium, 



Flower-heads on terminal peduncles. Leaves 2 or 3 



times pinnate ; with narrow linear or filiform lobes . 4. Matricaria inodora. 



The old yellow and white Chrysanthemums of our cottage gardens belong 

 to a north African species (0. coronarium). The late autumnal flowering 

 Chrysanthemums are varieties of the C. indicum from China. 



1. O. Leucanthemum, Linn. (fig. 523). Ox-eye Daisy. — A perennial, 

 with erect, simple, or slightly branched stems, 1 to 2 feet high, glabrous 

 or slightly downy. Radical leaves obovate and coarsely toothed, on 

 long stalks ; stem-leaves narrow, sessile, with a few coarse teeth. 

 Flower-heads solitary on long terminal peduncles, and rather large. 

 Involucral bracts bordered by a brown, scarious edge. Florets of the 

 ray white, more than half an inch long ; those of the disk numerous, 

 small, and yellow. 



In pastures, on banks, &c, throughout Europe and Russian Asia, 

 from the Mediterranean to the Arctic Circle. Extends all over Britain. 

 Ft. summer, commencing in spring. 



2. C. segetum, Linn. (fig. 524). Corn Marigold. — A glabrous, erect 

 annual, above a foot high, or rather more, with spreading branches. 

 Lower leaves obovate and stalked ; upper ones narrow and stem- clasp- 

 ing, generally with a few deeply cut teeth at the top. Flower- heads 

 rather large, on terminal peduncles ; the involucral bracts broadly 



