1768 



A TEXTBOOK OF THEORETICAL BOTANY 



following important families are included: Thymelaeaceae, Eleagnaceae, 

 Lythraceae, Punicaceae, Lecythidaceae, Rhizophoraceae, Combretaceae, 

 Myrtaceae, Onagraceae, Haloragidaceae, Hippuridaceae. To these Wett- 

 stein has added the Gunneraceae and the Callitrichaceae. 



Hutchinson, in an attempt to get a more precise definition for the orders, 

 has split up the Myrtiflorae into three orders, Thymelaeales, Lythrales and 

 Myrtales. The latter name is used by Hutchinson in a different sense from 

 that of Wettstein, who used it as equivalent to Myrtiflorae. There is much 

 to be said for Hutchinson's views and we indicate below the arrangement 

 of the families in the three orders recognized in his scheme. 



Thymelaeales Thymelaeaceae. 



Lythrales Lythraceae, Punicaceae, Onagraceae, Haloragidaceae, 



Callitrichaceae, Nyctaginaceae. 

 Myrtales Lecythidaceae, Rhizophoraceae, Combretaceae, 



Myrtaceae. 



It will be noted that Hutchinson excludes the Eleagnaceae, which he refers 

 to the Rhamnales (p. 181 3), while he includes in the Lythrales the family 

 Nyctaginaceae which, following Engler, we have placed in the Centro- 

 spermae (p. 1717). The Gunneraceae he merges into the Haloragidaceae. 



Were we considering all the families in detail it would be preferable to 

 follow this classification but as we shall only fully describe the Onagraceae 

 it seems desirable for convenience to make use of Engler's classification, 

 whereby a brief mention may be made of a number of important families 

 all embraced within the same order. 



The Thymelaeaceae are a relatively small family with about thirty- 

 eight genera and 550 species, which occur chiefly in temperate regions, 

 particularly in Africa. Most of them are shrubs with entire, alternate leaves 

 and racemose inflorescences. The flowers (Fig. 1654) are hermaphrodite 



I 



Fig. 1654. — Daphne odora. Flowers. 



