THE THISTLE FAMILV. 3,5 



ray-flowers are white and those of the disk yellow. Its principal leaves. 

 however, are from the base, where they lie in a rosette on the ^^round. IJsu- 

 ally they must be sought, so far away are they from the (lowers, and when 

 found are noticed to be obovate, or spatulatc, entire, or obscurely dcnialc. 

 Of this genus there are numerous attractive members, the majority of 

 them looking like daisies and having a tuft of leaves about their bases. 



SPICY FLEABANE, SALT-MARSH FLEABANE. 



Pliichca camphordta . 



FAMILY COLOUR ODOUR RANGE TIME OF BLOOM 



Thistle. Pifikish lavender. Strong. Florida to .Maaachusetts. AuguttOctober. 



Flcnuer-heads : growing on pubescent peduncles in open, corymbose cymes. In- 

 volucre: campanulate with lanceolate, pink-tinted bracts. J^icnotrs : all tubular. 

 Corolla : thrice, or five times, cleft at their apices. Lcai'cs ; alternate, short |M:ti- 

 oled ; oblong, or ovate, pointed at both ends, irregularly serrate, or dentate, 

 smooth above and pubescent on the veins underneath. Stem : two to three feel 

 high; erect; simple or mostly branched; leafy; pubescent or nearly glabrous. 



In the salt marshes we see the pale bloom of this plant, which is credited 

 with emitting an odour much like that of camphor and is therefore sought for 

 to keep away moths. It is interesting to find that the very slender flowers, 

 those which grow in the outer sides of the heads and are thrice cleft at their 

 apices, are the pistillate ones, while those central ones, which have their 

 corollas five-cleft, are perfect and mostly sterile. Other members of the 

 not very abundant genus show much the same characteristics. 



SMALL=FLOWERED LEAF=CUP. {P/a/c CLXXI.) 

 Polymnia Canadensis. 



FAMILY COLOUR ODOUR RANGE TIME OF BLOOM 



Thistle. Pale yellow. Scentless. North Carolina northward. J uneSfftfintfr . 



Flower-heads: growing in terminal and axillary corymbose clusters and having 

 an involucre of lanceolate, pointed bracts. Riiy-Jhrnh-rs : minute, or none. Disk- 

 floxvcrs : with tubular, five-toothed corollas. Achcnes : obovoid; three-ribbed. 

 Leaves : large ; opposite, occasionally alternate towards the base, with pulKsrcnt 

 petioles ; ovate, variously lobed, or lyrately pinnatifid; irregularly dentate ; thin; 

 dark green ; somewhat hairy. Stem: two to five feet high ; often branched; viscid- 

 pubescent. 



Between the three species of Polymnia which arc herein included a most 

 constant difference lies in their smooth achenes ; those of this particular 

 one showing but three ribs ; those of Polymnia llvcdalia. many ribs ; and 

 those of Polymnia laevigata, always five ribs. lUit this is not to be wondered 

 at, for so do plants often differ in details ; when their larger and more appa- 

 rent parts are similar. This genus is also one among the order Composila; 



