290 THE CROSSING OF FLOWERS. 



Class. 



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



(see fig. 28310). 



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



Mignonette {Reseda), House-leek {Sempervivtim), 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- 

 cantJms; see fig. 285^) Chrysohalanus (see fig. 285*). 



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



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

 Anemone (see fig. 284^) 



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

 phrodite flowers in which the stamens are unequal in length. 



14. DID YN AMI A. Includes flowers "with four stamens, two long and two short; e.g. the 



Foxglove (Digitalis), Snapdragon (Antirrhinum; see fig. 284^). 



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 ' and 284 «). 



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^), Hollyhock (Althcea), Mallow 

 (Malva), Baobab (Adansonia ; see fig. 284 ^o). 



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



Milkwort (Polygala), Fumitory (Fumaria; see figs. 285^ and 285^). 



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



groups; e.g. St. John's Wort (Hypericum), Melaleuca; (see figs. 284* and 284*). 



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* and 222'', p. 112). 



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



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

 Epipactis; see figs. 268 ^ and 268 ^ p. 255); also the Birthwort (Aristolochia; 

 see figs. 284 11 and 284 i^). 



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

 phrodite, and these are distinguished in the following way : — 



21. MONQECIA. 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 (Ricinus; see figs. 285'' and 

 285 8), Groton (see figs. 285 ii and 285 ^^), Liquidambar (see figs. 285 » and 285 1"). 



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 difierent plants, in various ways; 

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



24. CRYPTOGAMIA. Includes Non-flowering Plants. 



