298 



THE CROSSING OF FLOWERS. 



codendron), Laurels (e.g. LauTv,s nobilis and Sassafras), many Docks (e.g. Rnmex 

 alpinus and oUusifolv^s), the Wall Pellitory {Parietaria), and also some Saxi- 

 frages (e.£. Saxifraga controversa and tridactylites). 



The ninth group consists of species whose individuals each bear true herma- 

 phrodite flowers along with true pistillate and true staminate flowers. The Ash 

 J^ {Frax%nus excelsior; 



see flg. 230, p. 138) is 

 an example of this 

 group. 



Now come the 

 groups whose species 

 contain two or three 

 kinds of flowers dis- 

 tributed on two or 

 several plants. 



Species belonging 

 to the tenth group 

 bear true hermaphro- 

 dite flowers on one 

 plant and pseudo- 

 hermaphrodite female 

 flowers on another. 

 Examples of this are: 

 numerous Valerians 

 (e.g. Valeriana mon- 

 tana, Saliunca, su- 

 pina), some Dipsacese 

 (e.g. Scabiosa lucida, 

 Knautia arvensis), 

 many Saxifrages (e.g. 

 Saxifraga aquatica), 

 the cultivated Vine 

 (Vitis vinifera), many 

 Caryophyllaceae (e.g. 

 Dianthus glacialis 

 and prolifer, Lychnis 

 Viscaria, Silene noctiflora), and, especially, very many Labiates (e.g. GalaTnintha, 

 Glechoma, Marrubium, Mentha, Origanum, Prunella, Thymus). 



In the eleventh group we place those plants which develop true hermaphrodite 

 flowers on one plant and pseudo-hermaphrodite male flowers on another, as, for 

 example, numerous Ranunculacese (e.g. Ranunculus baldensis, Pulsatilla alpina, 

 vernalis, Ranunculus alpestris, glacialis), many Rosacese (e.g.Dryas octopetala, Geum 

 montanu/m and reptans), and many species of Vine (e.g. Vitis sylvestris, raacrocirrha). 



Tig. 286.— Type of a monoecious plant. 



' Oak ((Jiierms pedunmlata); pistillate flowers on the upper part of the twig, staminate 

 flowers (in pendent catkins) below, i^ A single pistillate flower of the same plant, 

 s Three staminate flowers of the same plant, i nat. size; 2 and s x 4. 



