Book I. 



DISTRIBUTION OF VEGETABLES. 



205 



Sect. V. Systematic Distinbution of Vegetables. 



959. TJie distribution of plants, considered in respect to their systematic classificatioyis, is 

 worthy of notice. The three grand systematic divisions of plants are acotyledoneae, dico- 

 tyledoneae, and monocotyledoneaj. A simplification of this division considers plants as 

 agamous, or phanerogamous, that is, without or with visible sexes. 



960. Plants of visible sexes. Taking the globe in zones, the temperate contain i part 

 of all the phanerogamous or visible sexual species of plants. The equinoctial countries 

 contain nearly J^, and Lapland only ^ part. 



961. Plants ivith the sexual parts invisible or indistinct. Taking the whole surface of 

 the globe, the agamous plants, that is, mosses, fungi, fuci, &c. are to the phanerogamae 

 or perfect plants, nearly as 1 to 7 ; in the equinoctial countries as 1 to 5 ; in the tem- 

 perate zones as 2 to 5 ; in New Holland as 2 to 11; in France as 1 to 2 ; in Lapland, 

 Greenland, Iceland, and Scotland, they are as 1 to I, or even more numerous than the 

 phanerogamous plants. Within the tropics, agamous plants grow only on the summits of 

 the highest mountains. In several of the islands of the Gulf of Carpentaria, having a Flora 

 of phanerogamous plants exceeding 200 species, R. Brown did not observe a single moss. 



962. In the whole globe, the monocotyledoneic, including the grasses, liliaceae, scita- 

 menese, &c. are to the whole of the perfect plants as 1 to 6 ; in the temperate zones 

 (between 36° and 52",) as 1 to 4; and in the polar regions as 1 to 20. In Germany, the 

 rtionocotyledonese are to the total number of species as 1 to 4^ ; in France as 1 to 4| ; iii 

 New Holland the three grand divisions of plants, beginning with the acotyledoneae, are 

 nearly as 1, 2i, and 1\. 



963. DicotyledonecB. In the whole globe, the monocotyledoneae are estimated, by 

 R. Brown, from Persoon's Synopsis, {Gen. B.em. on the Bot. of Terr. Aust. 1814,) to be 

 to the dicotyledoneae as 2 to 11 ; or with the addition of undescribed plants, as 2 to 9. 

 From the equator to 30° of north latitude, they are as 1 to 5. In the higher latitudes a 

 gradual diminution of dicotyledoneae takes place, until in about 60° north latitude and 

 50° south latitude they scarcely equal half their intertropical proportions. The ferns in 

 the temperate regions are to the whole number of species as 1, 2, and 5 ; that is, in the 

 polar regions as 1, in the temperate countries as 2, and in the intertropical regions as 5. 

 In France, ferns form part of the phanerogamous plants ; in Germany j in Lap- 

 land ^. 



964. The natural orders of perfect or phanerogamous plants are variously distributed in 

 different countries. The following Table gives a general view of the relative proportions 

 of several natural orders of perfect plants in France, Germany, and Lapland. 



Names of Natural Orders. 



Cyperoideae 



Graminese - - 



Junceae - - 



These three Families together 

 Orchide^ - - - 

 Labiatae - - _ 



Rhinantheae et Scrophuleas - 

 Boragineae 



Ericeae et Rhododendreae 



Compositae 



Umbelliferee 



Crucifer^ - 



Malvaceae 



Caryophyllece 



Leguminoseae 



Euphorbeae 



Amentaceae 



Conifereae - - 



Number of Species in 

 different Countries. 



Fran. 



134 

 284 

 42 



460 

 54 

 149 

 147 

 49 

 29 

 490 

 170 

 190 

 25 

 165 

 230 

 51 

 69 

 19 



3645 



Lapl. 



102 



143 

 20 



265 

 44 

 72 

 76 

 26 

 21 



238 

 86 



106 

 8 

 71 

 96 

 18 

 48 

 7 



1884 



124 

 11 



7 

 17 



6 

 20 

 38 



9 

 22 



29 

 14 

 1 



23 

 3 



497 



Ratio of each Family to the 

 whole of the Phanero- 

 gamous plants in these 

 Countries. 



Fran. 



Germ. 



533 



1 



27 



1-apl. 



