LAURACEJE. 451 



genus Tetranthera, which finds representatives in all warm countries. 

 Hence there are only six genera common to both hemispheres : 

 Cryptocarya, Ocotea, Persea, Phcebe, 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 Dicypettium from 

 Brazil ; Misanteca from Mexico ; Sassafridium from Costa Eica and 

 Veraguas ; Boldic from Chili ; Sassafras from North America, 

 Bihania in Borneo ; Sympliy so daphne from the Antilles. Of the 

 genera with but few species we only find Nesodaphne in New Zealand, 

 Ampelodaphm and Pleurothyrium in a small region of tropical America, 

 Bavensara 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 Lauracece, of the series IlligerecB, Gyrocarpete, Cassythece, 

 and Hernandiea, 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- 

 ilielium, and one of the five described in Gyrocarptts, 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 

 Lauracece 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 of a 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, 



I 1 (.1 M 



