GENERA IN CLASS XIX. SYNGENESIA. 



105 



Order 3. Polygamia frustranea, comprehends such plants 

 as have the florets of the disk bisexual, and those of the radius 

 neuter. This order contains sixteen genera, all radiate, viz. He- 

 lianthus (sun-flower). ...Rudbeckia.... Coreopsis. ...Gorteria... 

 Osmites... Zcegea...Centaurea*....Sclerocarpus...Didelta.... 

 Mussinia...Lapeyrousia... Berekheya....Tithonia...Galardia 

 ...CosMEA...and Pallusia. 



Order 4. Polygamia necessaria, comprehends such plants 

 as have flowers of the disk male, and those of the radius female. 

 This order contains twenty-two genera, most of which are radi- 

 ate, viz. Milleria...Silphium..,Chrysogonum...Melampodium 

 ...Calendula (wiarygo/d)...ARCTOTis...OsTEOSPERMUM...OTHON- 

 na (African 7'#gtforO".PoLYMNiA...ERiocEPHALUs...FiLAGO (cud- 

 weed)... Micropus... Baltimora... Hippia... Psiadia ... Unxia... 

 Iva...Wedelia ... Acicarpha ... Parthenium ... Arctotheca... 

 Trixis. 



Order 5. Polygamia segregata. This order comprehends 

 such plants as have many partial florets contained in the common 

 calyx, which separate and surround the floscula. This order con- 

 tains sixteen genera; Tetranthus.,.Rolandra...Nauenburgia... 

 Calycera ...Nocc;ea...Boopis...Stcebea...G2dera...Brotera... 

 Echinops (g/o6e-^to/e)...ELEPHANTOPUs {elephant's foot).., ~N as- 



SAUVIA...JuNGrA...GuNDELIA...SPHiERANTHUS...and CrASPEDIA. 



Order 6. Monogamia, comprehends such plants as have sim- 

 ple flowers. This order contains seven genera, viz. Strumpfia 

 ... Seriphium ... Corymbium ... Jasione ... Lobelia {cardinal's 

 flmm)... Viola (violet).,. and Impatiens (balsam)\. 



*• 



* The corollulse of the centaurea are all tzibulose, hut those of the radius differ 

 from those of the disk, which brings it within the definition of a radiate flower; how- 

 ever, Linnams, in his description of the centaurea, in the Genera Plantarum, hafe 

 not called the corolla radiate, but tubulosa difformis, tuhdose of different forms. 

 Author. 



f The plants of this class are removed, by general consent, into the class Pen- 

 tandria, to which they properly belong. Here they disfigure a class that has the 

 strong recommendation of being altogether natural. We have preserved them, how- 

 ever, here, to illustrate the Sexual System of Linnaeus. Editor. 



