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18*
PREFACE.

descends below the freezing point, but the island is exposed to frequent and violent winds.

The numbers in the following Table are taken, for Aden, from Dr. T. Anderson's 'Florula Adenensis' (Journ. Linn. Soc. Lond. vol. v. Suppl.), a work drawn up on the same standard as to the limits of genera and species as the Hongkong Flora; and for Ischia, from Prof Gussone's 'Enumeratio Plantarum Vascularium in Insula Inarime provenientium' (Neapoli, 1854). From the latter however I have found it necessary, in order to establish a fair comparison, to deduct the cultivated species, and to reduce the remainder to the specific and generic standard of our Hongkong Flora.

Hongkong . Aden . . . Ischia . . . Orders. Genera. Species. .2 u II ii -is It |l Woody. Herba- ceous. Proportion of woody to herbaceous. Total.

42



19 66


Ito 2-105 1 to 4-000 1 to 11-000


-024 2-024 9-645 -805 1-019 2-034 e Orders most numerous in species in Hongkong are*— GraminesB . . . 86 species. MyrsinacesD . . . 15 species Filices ....

Laurineae . . .

Leguminosae . . 72 Apocjnaceae . .

CompositsB . . 67 ConvolvulaceaB .

Cyperacese . 62 Liliacese . . .

Euphorbiaceae . 52 Ternstroemiaceae

Eubiaceae . . . 42 Malvaceae . . .

OrchideaB . . . 36 Eosaceae . . .

Urtice© . . . 27 Asclepiadeae . . . 11 Scrophularinese . 21 Solanaceae . . . 10 Acanthaceae . . 18 Polygonace89 . .

Verbenacese . . 17 AmentaceaB . .

Labiatae . . . 16

Orders have 

species each.

Orders have 4 £ 

species each.


j>

„ 3 



)5

5, 2 




„ 1 

  • The discrepancies between the total number of Orders and genera in this and the pre-

ceding Tables is owdng to the half-naturalized species being here reckoned, but necessarily- excluded when considering geographical areas.