DIRECTIONS FOR THE LEARNER. 



AT first study only those plants which have large flowers. Do not 

 attempt to determine the name of a plant unless you have specimens 

 which show not only the flowers, but the buds, the fruit (at least, partly 

 grown), the leaves from all parts of the stem, and the roots. If you can- 

 not readily distinguish the parts of the flower and their relations to each 

 other, lay it aside until the study of easier plants has given you more 

 skill. 



If the small veins of the leaves do not form a network, and the 

 organs of the flower are all in threes, the plant is probably an endogen 

 and, therefore, not described in this book. If the calyx and corolla are 

 not both present the flower is said to be apetalous. A few such flowers 

 are described, and the orders are to be sought under the last division of 

 the Analytical Key. Clematis, Allolropa and Glaux are apetalous genera 

 having the calyx corolla-like. 



It will be best to write out a description of the plant before attempt- 

 ing to analyze it. Some good text-book, such as Gray's " How Plants 

 Grow," should be constantly referred to in search of the proper descrip- 

 tive terms. Suppose the following to be a description of the plant in 

 hand, the words in parentheses indicating a more concise way of telling 

 the same thing: A hairy plant one or two feet high, with opposite leaves 

 and no stipules (exstipulate); the leaves narrow and blunt, broader near 

 the upper end (spatulate); the small pinkish flowers growing on short 

 stems (pedicels) close together along one side of the main stem for sev- 

 eral inches to the end (in a close raceme); the calyx of 5 sepals united to 

 form a narrow tube (tubular, 5-lobed) nearly half an inch long, marked 

 by 10 ridges (nerves); the 5 petals distinct from each other and very nar- 



