THE STEM AND BRANCHES. 193 



chickweed and sandwort ; others have tall and 

 comparatively stout stems, like wheat, oats, and 

 barley, or still more, like the sunflower. As a 

 rule, annuals are not very large ; but a few rich 

 seeds produce strong young plants which even 

 within a single year attain an astounding size ; 

 this is the case with the garden poppy, the 

 tobacco plant, and the Indian corn, and even 

 more so with certain climbing annuals, such as 

 the gourd, the cucumber, the melon, and the 

 pumpkin. 



Many plants, however, find it pays them better 

 to produce a hard and woody stem, which lasts 

 from year to year, and enables them to put forth 

 fresh leaves and shoots in each succeeding 

 season. Among these, again, great varieties 

 exist. Some have merely a rather short and 

 stout stem with many bundles of water-vessels, 

 as in the pink and the wallflower. Their growth 

 is herbaceous. Others, however, produce that 

 more solid form of tissue which we know as 

 wood, and which is made up of cells whose walls 

 have become much thickened and hardened. 

 Among the woody group, again, we may dis- 

 tinguish many intermediate varieties, from the 

 mere shrub or bush, like the heath and the 

 broom, through small trees like the rhodo- 

 dendron, the lilac, the hawthorn, and the holly, 

 to such great spreading monsters of the forest as 

 the oak, the ash, the pine, the chestnut, and the 

 maple. 



Once more, some plants produce an under- 

 ground stem, and send up from this fresh annual 

 branches. That is the case with hops, with 

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