SPERM A TOPH VTA 403 



(Impatiens), etc. The flowers are regular or irregular, mostly hypogy- 

 iious, and syncarpous. The perianth is mostly pentamerous but the 

 stamens are usually reduced to eight. Most memljers are isocarpic. 

 This order has developed parallel with the Geraniales, being distinguished 

 from it chiefly by certain obscure ovule characters. 



Rhamnales. This order includes about 1,100 species of woody plants 

 belonging to 2 families, the Rhamnaceae, represented by the buckthorns 

 (Rhamnus) and Ceanothus, and the Vitaceae, including the grapes (Vitis) 

 and Virginia creeper (Parthenocissus) . The flowers are regular, mostly 

 hypogynous, syncarpous, and tetracyclic. The perianth is trimerous or 

 tetramerous. The Rhamnales have developed parallel with the Gera- 

 niales and Sapindales, differing from them chiefly in having the stamens 

 opposite the petals instead of alternate with them. 



Malvales. This is an order of 8 familes and about 2,300 species of 

 herbs and woody plants. The best-known families are the Tiliaceae, 

 represented by the basswood (Tilia), and the Malvaceae, to which belong 

 the mallows (Malva), hollyhock (Althaea), cotton (Gossijpium), etc. The 

 flowers are regular, hypogynous, syncarpous, and have a pentamerous 

 perianth. The stamens are usually indefinitely numerous (rarely five) 

 and more or less united. The placentation is axial. 



Parietales. The Parietales, containing 30 families and about 5,000 spe- 

 cies of herbs and woody plants, is an order representing an extremely con- 

 fused classification. The most familiar forms are the violets (Viola). 

 The order is characterized by parietal placentation, its other characters 

 being rather inconstant. The flowers are regular or irregular; hypogy- 

 nous, perigynous, or epigynous; and mostly syncarpous. They are typ- 

 ically pentamerous, but the stamens may be 3, 5, 10 or indefinitely 

 numerous. 



Opuntiales. Here belongs a single family, the Cactaceae, with about 

 1,100 species indigenous to America. The flowers are regular, epigy- 

 nous, and syncarpous; they are peculiar in being spiral and polymerous. 

 Thus the group represents a combination of primitive and advanced 

 features. 



Myrtales. This is a large tropical order of herbs and woody plants. 

 It contains about 7,500 species grouped into 19 families, of which the 

 Myrtaceae and Onagraceae are well known. The myrtles (Myrtiis), 

 Eugenia, and Eucalyptus belong to the Myrtaceae, while the fireweeds 

 [Epilohium), evening primroses (Oenothera), and Fuchsia are familiar mem- 

 bers of the Onagraceae. The flowers are mostly regular, perigynous or 

 epigynous, and syncarpous. The perianth is mostly pentamerous and 

 the stamens often indefinitely numerous. The carpels vary from two to 

 many. This order resembles the Rosales in many ways, but here the car- 

 pels are never free. 



