EXOGEN.E MONOCHLAMYDE.E. 



159 



Avocado pear, an eatable West Indian fruit, is borne by 

 Persea gratissima. 



TYPICAL GENERA. Laurus, Cinnamomum. 



Litssea Baueri. 1. A male flower. 2. A female. 3. A stamen, with a gland at 

 the base. 4. An anther, with the recurved valves. 5. A cluster of fruit. 6. A 

 cotyledon seen from within, with the plumula adhering to the inner face. 



134. Polygonacea. Herbaceous plants, rarely shrubs. 

 Leaves alternate, their stipules usually cohering in the form of 

 an ochrea. Calyx inferior, imbricated. Stamens definite. 

 Ovary superior, with a single erect ovule. Nut triangular. 

 Seed with farinaceous albumen ; embryo inverted ; radicle 

 remote from the hilum. 



USES. Rumex scutatus, Acetosa, and others, are the Sorrel 

 plants used in cookery. Rhubarb is the root of several species 

 of Rheum ; similar properties, only more feeble, are found in 

 Rumex alpinus. In addition to acid and purgative qualities, 

 a great degree of astringency manifests itself, as in the roots 

 of Rumex, and the bark of Coccoloba uvifera, which is said 

 to yield a kind of Kino. It is reported that the seeds of Poly- 

 gonum aviculare are emetic, notwithstanding that those of 

 P. Fagopyrum and tataricum are employed as food in some 

 places ; the leaves of Polygonum hydropiper and others are 

 acrid. 



TYPICAL GENERA. Rumex, Polygonum, Rheum. 



