LAURACEZ, 451 
genus Zetranthera, which finds representatives in all warm countries. 
Hence there are only six genera common to both hemispheres: 
Cryptocarya, Ocotea, Persea, Phebe, Lindera, Tetranthera. Only one 
Species occurs in Europe, a Laurus. In the east of North America, 
excepting only two or three members of more southern genera, 
Lindera and Sassafras alone occur. Some small genera, consisting 
of but one or few species, are limited to a very small geographical 
area. The following are monotypical: Silvia and Dicypellium from 
Brazil; Misanteca from Mexico; Sassafridium from Costa Rica and 
Veraguas; Boldu from Chili; Sassafras from North America, 
Bihania in Borneo; Symphysodaphne from the Antilles. Of the 
genera with but few species we only find Nesodaphne in New Zealand, 
Ampelodaphne and Pleurothyrium in asmall region of tropical America, 
Ravensara in Madagascar. The genus Lindera is divided between 
the floras of Japan and North America. Out of about a thousand 
species there are a little over five hundred in America and nearly as 
many in the Old World. 
The other Lauraceae, of the series I. lhgeree, Gyrocarpee, Cassythee, 
and Hernandiee, including altogether some fifty species from hot 
countries, do not materially alter this relation. Of seven species of 
Hernandia three are American, as are the five species of Sparattan- 
thelium, and one of the five described in Gyrocarpus, and apparently 
one species of Cassytha. The remaining twenty-eight species belong 
to the Old World, mostly to Australia. Thus of the 1050 species of 
Lauracee America possesses some 530. 
The following characters are common to all these plants ; the want 
of stipules, the regularity of the flower; the concavity of the recep- 
tacle, making the perianth and androceum more or less markedly 
perigynous ; the existence of a double perianth ; the valvular dehis- 
cence of the anthers ; the possession ofa solitary anatropous descend- 
ing ovule, with its micropyle turned upwards and inwards under the 
point of attachment; the indehiscence of the one-seeded fruit; 
the want of albumen in the seed. These may be pronounced as 
absolute. 
Among the variable ones come the arrangement and form of the 
leaves, which are usually alternate, rarely whorled, usually simple, 
Ge 2 
