EXOGENS OR DICOTYLEDONS 



can think of examples among cultivated plants. On the 

 California deserts there is a shrubby L,eguminosae, the mes- 

 quite, whose seeds the Indians eat. Sometimes it is the 

 foliage that is used for food; the clovers and alfalfa are ex- 

 amples. Some Leguminosse are shrubs or trees valuable 

 for timber. Gum arabic is produced by some kinds of 

 Acacia. 



The flowers of I/eguminosae have usually some of their 

 petals partly united. The flowers of all the higher groups 

 of dicotyledons have all their petals united into a tube, at 

 the base at least. One of the lowest of these groups is 

 called the heath group, because the heath, or heather, of 

 Europe belongs here. It includes some very large and in- 

 teresting families, but the California members live mostly 

 in the mountains or forests. Some of these are the man- 

 zanita, the madrone, the crimson snow-plant, the azalea 

 and the rhododendron; cranberries, huckleberries and the 

 like belong in this group, also the pretty trailing arbutus of 

 the Eastern States. To another group belong the true 

 primrose that we read about in English books, the Chinese 

 primrose and the cyclamen that we cultivate in pots, also 

 our own shooting star and the sturdy little pimpernel. 

 Another group is mainly foreign; the ebony and persim- 

 mon belong to it. 



The next group we have already studied. It includes 

 the blue-eyes, Gilia, forget-me-not, nightshade and morn- 

 ing-glory families. Watch for the late-flowering members 

 of these families. There are several late Phacelias, and 

 very pretty Gilias are found in the foot-hills and mountains 

 during the summer months. The dodder is in flower all 

 summer, and that big, coarse cousin of the nightshade, the 

 "Jimson" weed, unfolds its .huge white flowers in the sum- 

 mer and autumn. 



The next group of plants, too, we have studied, call- 

 ing them " plants of high rank." These families, also, 



181 



