6 THE PLANT WORLD. 



leading character for a separation of genera. My aim in this series of 

 papers will be to provide a simple means for distinguishing at sight 

 the more important families among the flowering plants. Once sure 

 of the family, it is not difficult to discover the genus and species with 

 the aid of any good maniial. It is to be hoped that knowledge thus 

 acquired and applied in rambles through field and forest may arouse 

 in those for whom these articles are written a desire to understand 

 more of this most charming of the natural sciences. 



As the ferns and conifers can be most advantageously studied 

 elsewhere, we shall take up the higher division of the flowering plants, 

 known to botanists as Angiosperms, the name signifying plants which 

 produce their seeds in a closed cavity called the ovar5\ The Angio- 

 sperms are divided into two great sections, each of which may be 

 easily recognized, and which are of such importance that their names 

 and characteristics vshould be memorized : 



/. Monocotyledons. Plants which produce, on germination, a 

 single seed-leaf, or cotyledon. Leaves for the most part with veins 

 running from base to apex, or from midrib to margin, in parallel 

 series. Parts of the flower nearly always in 3's or some multiple of 3. 

 Wood of the stem with no annual rings or layers. Examples: Palm, 

 lily, grasses, sedges. 



3. Dicotyledons. Plants which produce, on germination, usually 

 two seed-leaves or cotyledons. Leaves with reticulated or netted 

 veins. Parts of the flower never in 3's, mainly in 4's or 5"s, or some 

 multiple of these numbers. Wood of the stem with marked annual 

 rings or layers. Examples: Maple, elm, biittercup, daisy, i)ea, 

 morning-glory. 



The great mass of our northern vegetation, including all the 

 native trees (except conifers) belongs to the second class. The 

 Monocotyledons are the simplest and lowest of all flowering plants; 

 this is proven, not only by their structure, but by the fact that m past 

 geological time they appeared <ni the earth's surface in advance of the 

 Dicotyledons. With the simplest of the series as our starting point, 

 therefore, we shall visit the ponds and marshes next month in order 

 to study a group of six nearly related families, including the Pond- 

 weeds, Arrowheads and Cat -tails. 



Mr. F. A. Lucas of the U. S. National Museum, as one of the rep- 

 resentatives of the United States in the Fur Seal controversy, is now 

 studying the habits of the seals in the Behring Sea. He will make a 

 collection of plants and will write an article for the Pl.^^xt World on 

 the floral features of St. Paul's Island. 



