Statistics of the Flora of the Northern States. 213 



The numerical elements of our Phaenogamous flora, consid- 

 ered as to classes, are, as the tabular view shows : 



Dicotyledonese or Exogense, 1490 species in 522 genera. 



MonocotyledoneEe or Endogense, 601 " 159 u 



Total Phsenogamous indigenous plants, 2091 " 681 " 



Or about 2-| Dicotyledonous to one Monocotyledonous species. 



Their distribution among the 132 Natural Orders represented 

 in our flora (Eesedacece and Dipsacece of the above table being 

 excluded, as having no indigenous representatives), is shown in 

 the following: 



List of the principal Phcenogamous Natural Orders represented in the 

 flora of Northern United States, arranged according to the number of 

 \ indigenous species they severally comprise. 



Species | Species. 



CompoaiitaB, 273 Liliaceae, 24 



about £th of the 2091 Phanerogamia. Rubiaceae, 23 



Cyperaceae, about x \j-th, " 2 3 3 Saxifragaceae, 22 



Gramineae, about T l s th, " 162 Polygonaceae, 22 



Leguminosae, about ^th, " 91 Asclepiadaceae, 21 



Rosaceae, about ^V tn , " 71 Melanthaceae, 2 1 



Ericaceae, 62 Coniferae, 20 



Scrophulariaceae, 54 Violaceae, Hypericaceae, and 



Orchidaceae, 51 ! Smilacese, each 18 



Ranunculaceae, 49 Primulacese, Borraginacese, 



Labiatae, 49 and Naidacese, each 16 



Cruciferae, 46 Convolvulacese and Urticacese, 



Umbelliferae, 37 each, 15 



Onagracese, 36 Polygalacess, 13 



Caryophyllaceae, 30 Lobeliacese, Lentibulacese, Pole- 



Euphorbiaceae, 28 moniacese, and Alismacese,each, 12 



Caprifoliaceae, 27 Cornacese, and Hydrophyllacese, 



Juncacpae, 26 j each, 11 



Cupuliferae, 25 Sapindacefe, Aquifoliacese, Che- 



nopodiacese, and Betulacese, 



each, 10 



Salicaceae, 24 

 Gentianacese, 24 



Only 46 of our orders have 10 or more indigenous species : 63 

 orders have from 2 to 9 species, and 23 orders are represented 

 each by a single species. The average allows 15*09 species to 

 an order. 



Alphonse De Candolle and others have remarked that in almost 

 every flora of the temperate zone which is pretty thoroughly 

 known, the eight or nine largest families comprise half of its 

 Phaenogamous plants. In the present case the first nine families, 

 having 1026 species, lack nineteen of making half; the sum of 

 ten families exceeds the_moiety by thirty. The result is nearly 

 the same as that brought out by De Candolle from a similar 

 schedule, tabulated by him from Beck's Botany of the Northern 



