Every time when I come to San Francisco I would stay at my brother-in-laws .  The yards of the house are so large that they are taken care of by professional gardeners who come to do the work once a week.  I pay little attention to their gardening, and because I am just a quest, so I hardly concern the layouts of the vegetation in the yards. 

Now is the time for removing weeds and applying fertilizer, so the gardeners are working longer than they used to be.  Yesterday when they came, I happened to smoke in the backyard.  All of a sudden I found there are several thickets of reed sparsely dotted among other plants.  Then I asked one of the gardeners how come people use reed as kind of a decoration in their garden.  He said it is not uncommon that reeds with weeping and well-trimmed branches shaking slightly in many carriages are to be seen at residential areas here in California, but he doesnt know why people love to use that cheap, thatch-like plant as a decoration.  I dont know, either; maybe the answer can only be found in that classic poem quoted below:   

蒹 葭 （出自詩經秦風）