VOL. III.] Flora of the Cape Region. 229 



mus are found across the continent, while others may by future 

 exploration have their now apparently widely separated habitats 

 connected along^ a more southern route. 



The number of genera in the ninety-nine orders found in the re- 

 gion is three hundred and ninety, and two hundred and thirty of 

 them are represented by a single species, the flora being essentially 

 insular the proportion of genera to species is large as in island 

 floras. The largest genera are: Euphorbia with about twenty 

 species, Cereus with nine, Acacia nine, Desmodium eleven, Cassia 

 seven, Dalea seven, Ipomaea fourteen, etc. Leguminosae, the largest 

 order, has ninety-five species that are in most cases widely dis- 

 tributed throughout the region and abundant, so that this class of 

 plants is the predominating one of the region. The second largest 

 is Compositae of eighty species; some of them are very common 

 and some such as Franseria, Eupatorium, Brickellia, become almost 

 arborescent. Euphorbiaceae has forty-eight, many of them small 

 prostrate species of the genus Euphorbia, but one species of Phyl- 

 lanthus is a small tree. Malvaceae has twenty-two, Graminae fifty- 

 two, Filices twenty-two, Convolvulaceae twenty-five, Acanthaceae 

 seventeen. The relative positions of Leguminosae and Compositae 

 in the flora of the world and that of Mexico are reversed and other 

 large orders occupy different positions in the scale, but the region 

 considered is so small that such comparisons have little value. 

 • By the term "Mountain Flora" is meant those plants growing 

 only upon or very near to the top of the highest ridges and sum- 

 mits of the mountains. Some plants of the lower elevations, such 

 as Heterospermum, Behria, Centunculus, grow also up the mount- 

 ains to their highest elevations, and others of the mountains are 

 washed down the streams to the lower elevations, especially by the 

 waters of the San Jos6 River; so that such strictly mountain plants 

 as Clevelandia, Heterotoma and others can sometimes be found in 

 damp stream beds, but the great mass of the mountain flora is 

 peculiar to the high elevations. The hundred and forty-eight species 

 belong to a hundred and seventeen genera; the orders containing 

 the greatest number of species are: Fihces with sixteen, Rosaceae 

 six, Leguminosae fourteen, Compositae twenty-one, Caryophyllaceae 

 six, Orchidaceae nine. The largest genera are: Desmodium with 

 three species, Notholaena of three; several others have two, but most 

 of them are represented by but a single species. Forty-two of the 

 hundred and forty-eight grow also in Alta California and ninety-five 



