438 



THE KINDS OF PLANTS 



perfect, fertile, yellow, corolla 5-cleft; receptacle convex, partially chaffy; 

 involucral bracts small, dry, in several series, outermost shortest: achenes 

 round or ribbed, smooth: pappus none or a slight border. There are a 

 number of cultivated plants in this genus. 



A. Cotula, DC. May-weed. Annual, bushy, erect, 1-2 ft.: heads ter- 

 minal, corymbed, 1 in. broad; rays usually white, neutral; disk flowers yel- 

 low: leaves alternate, mostly sessile, finely pinnatifid. Roadsides. Europe. 



14. CALENDULA. Pot Marigold. 



Erect, quick-growing annuals, with terminal large yellow or orange heads 

 with pistillate rays: involucre of many short green scales; torus fiat; pap- 

 pus none: achenes of the ray florets (those of the disk florets do not mature) 

 curved or coiled. 



C. officinalis, Linn. Common pot marigold. A common garden annual 

 from the Old World, with alternate entire sessile oblong leaves: 1-2 ft. 



15. CHRYSANTHEMUM. Chrysanthemum. 



Erect herbs, annual or perennial, with alternate lobed or divided leaves: 

 rays numerous, pistillate and ripening seeds; torus usually naked, flat or 

 convex; pappus none. 



a. Achenes of ray florets winged. 



C. morifolium, Ram. (C. sinense, Sabine). Greenhouse 

 chrysanthemum. Tall and mostly strict, with lobed, firm and 

 long-petioled alternate leaves: flowers exceedingly various. 

 China. 



aa. Achenes not winged. 



C. Leucanthemum, Linn. Whiteweed. Ox-eye daisy. Fig. 

 189. Perennial, with many simple stems from each root, rising 

 1-2 ft., and bearing alternate oblong sessile pinnatifid leaves: 

 heads terminating the stems, with long white rays and yellow 

 disks. Fields everywhere in the East, and spreading West. 



16. RUDBECKIA. Cone-flower. 

 beck' hh-ta Perennial or biennial herbs, with alternate leaves and 



showy yellow-rayed terminal heads : ray florets neutral ; scales 

 of involucre in about 2 rows, leafy and spreading; torus long or conical, with 

 a bract behind each floret: achenes 3-angled, with no prominent pappus. 

 Strong field plants. 



R. hirta, Linn. Black-eyed Susan. Ox-eyed daisy in the East. Fig. 557. 

 Biennial, 1-2 ft., coarse-hairy, leaves oblong or oblanceolate, nearly entire, 

 3-nerved: rays as long as the involucre or longer, yellow, the disk brown; 

 torus conical. Dry fields. 



R. laciniata, Linn. Two to 7 ft., perennial, smooth, branching: leaves 

 pinnate, with 5-7-lobed leaflets, or the upper ones 3-5-parted: rays 1-2 in. 

 long; torus becoming columnar. Low places. 



