SUPPLEMENT 



ure and organic matter dissolved therein, and producing true flowers 

 and seeds ; what we eat of the latter plant is the consolidated flower 

 cluster, that is, the individual fruits and their stems grown juicy. 

 The Tradescantia, or wandering-Jew, of cultivation, is usually 

 assigned to another but a nearly related gronp. 



The next group considered in the Reader is known as Spadiciflorse, 

 from the spadix-like inflorescence. Duckweeds, Lemnaceae, are minute 

 floating plants, common the world over on quiet pools ; each plant is 

 a small green disc with, usually, one descending root ; they are rarely 

 found in flower and then the flower is reduced to a single stamen or 

 pistil ; ordinarily they reproduce rapidly by division. There are 

 various other floating plants of the order Naiadaceae, which are com- 

 monly assigned here ; they are known as pondweeds, ditch grass, &c., 

 and they choke up our reservoirs and irrigating ditches. The calla, 

 Richardia Africana> is a type of a group of about one thousand 

 species, nine-tenths of them tropical. They are known as Aroids : 

 "Jack in the pulpit," sweet flag and skunk cabbage, common in our 

 Eastern States, belong here ; so does our cultivated black lily with its 

 livid colors and fcetid odor that attract carrion-eating insects. The 

 tropical aroids sometimes attain most luxuriant growth ; one from the 

 Island of Sumatra produced in Kew Gardens, London, a spathe six 

 feet long and about three in circumference, with leaves and rootstock 

 in the same proportion. There are climbing aroids that clamber over 

 the tops of forests and send down aerial roots, which fasten themselves 

 in the soil. 



There are about a thousand known species of palms also. Two 

 genera are native to California, one species, Washingtonia filifera, 

 Wend., being common in cultivation ; a tree of this species, in Los 

 Angeles, known to be fifty years old, is sixty feet high. Several foreign 

 palms, too, thrive well out of doors in our climate, and since palms 

 are so typical of the vegetation of the tropics, and have there so great 

 economic value, it is desirable to emphasize the group in connection 

 with Geography work. As can be seen from our own palms, the 

 inflorescence is usually crowded, consisting of great numbers of small 

 flowers, sometimes perfect, sometimes staminate or pistillate only. 

 The fruits may be berries, drupes or nuts. Palms growing in a very 

 hot and humid climate must have enormous leaf surface for sufficient 

 transpiration. The following figures are taken mainly from Kerner : 

 A Brazilian palm has pinnate leaves seventy feet long and twenty-five 

 feet broad ; the Talipot palm of Ceylon has palmate leaves eighteen 

 by twenty-five feet, and other parts in proportion ; in the course of 

 forty years, its trunk attains a height of about seventy feet ; it then 



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