290 THE CROSSING OF FLOWERS. 



CLASS. 



10. DECANDRIA. Ten stamens in each flower; e.g. Rue (Ruta; see fig. 290), Phytolacca 



(see fig. 283 10 ). 



11. DODECANDRIA. Number of stamens not quite definite, 11-20 in each flower; e.g. 



Mignonette (Reseda), House-leek (Sempervivum), Agrimony (Agrimonia Eupa- 

 toria; see figs. 285 : and 285 2 ). 



12. ICOSANDRIA. More than twenty stamens in each flower, situated on the edge of 



the cup-shaped receptacle (or calyx-tube), their position, therefore, being above 

 or on a level with the stigma; e.g. Rose (Rosa), Almond (Amygdalus\ Caly- 

 canthus; see fig. 285 3 ) Chrysobalanus (see fig. 285 4 ). 



13. POLYANDRIA. 20-200 stamens in each flower, springing from the receptacle below 



the pistil; e.g. Poppy (Papaver), Lime (Tilia; see figs. 284 * and 284 2 ) and 

 Anemone (see fig. 284 3 ) 



In the 14th and 15th Classes Linnaeus puts all Phanerogams with herma- 

 phrodite flowers in which the stamens are unequal in length. 



14. DIDYNAMIA. Includes flowers with four stamens, two long and two short; e.g. the 



Foxglove (Digitalis), Snapdragon (Antirrhinum', see fig. 284 6 ). 



15. TETRAD YN AMI A. Includes flowers with six stamens, four long and two short; 



e.g. Mustard (Sinapis), Wall-flower (Cheiranthus), Bitter-cress (Cardamine; see 

 figs. 284 7 and 284 8 ). 



The 16th-20th Classes include all Phanerogams whose stamens are joined in 



any way either to one another or to the pistil. They are distinguished 



from one another thus : 



16. MONADELPHIA. The filaments of all the stamens of a flower are joined into a tube; 



e.g. Tamarind (Tamarindus Indica; see fig. 284 9 ), Hollyhock (Althcea), Mallow 

 (Malva), Baobab (Adansonia ; see fig. 284 10 ). 



17. DIADELPHIA. The filaments of the stamens are united and form two groups; e.g. 



Milkwort (Poly gala), Fumitory (Fumaria; see figs. 285 5 and 285 6 ). 



18. POLYADELPHIA. The filaments of the stamens are united and form three or more 



groups; e.g. St. John's Wort (Eypericum), Melaleuca; (see figs. 284 4 and 284 5 ). 



19. SYNGENESIA. The anthers of the stamens in each flower are joined together into a 



tube; e.g. in Lobelia, Hawkweed (Hieracium; see figs. 222 4 and 222 7 , p. 112). 



20. GYNANDRIA. The stamens are united with the pistil; e.g. the Orchids: Phalcenopsis , 



(see figs. 258 l and 258 2 , p. 227); Cypripedium (see figs. 267 l and 267 2 , p. 249); 

 Epipactis-, see figs. 268 2 and 268 3 , p. 255); also the Birthwort (Aristolochia-, 

 see figs. 284 n and 284 12 ). 



Now come those plants whose flowers are not hermaphrodite or not all herma- 

 phrodite, and these are distinguished in the following way : 



21. MONCECIA. Flowers monoecious, i.e. the flowers which contain only stamens or only 



pistils, are separated but grow on the same plant, e.g. the Maize (Zea Mais), the 

 Oak (Quercus-, see fig. 286); the Castor- oil Plant (Ridnus; see figs. 285 7 and 

 285 8 ), Croton (see figs. 285 n and 285 12 ), Liquidambar (see figs. 285 9 and 285 10 ). 



22. DICECIA. Flowers dioecious, i.e. the flowers containing stamens only are found on 



certain plants, and those with pistils only on other plants; e.g. the Willow 

 (Salix-, see fig. 287). 



23. POLYGAMIA. Flowers polygamous, i.e. staminate, pistillate, and hermaphrodite 



flowers are all found either on the same or on different plants, in various ways; 

 e.g. the Ash (Fraxinus; see fig. 230, p. 138). 



24. CRYPTOGAMIA. Includes Non-flowering Plants. 



