CHAPIN Af 
MORPHOLOGY OF THE VEGETATIVE ORGANS 
Morpuo.oey treats of the form and structure of organs, 
especially as to their developmental relations. For exam- 
ple, morphological study indicates that a fundamental 
organ may develop into a foliage leaf, into a scale or bract, 
or into the parts of the flower. In order to understand the 
natural classification of plants, it is first necessary to be 
familiar with their morphology. To interpret and use 
descriptions, it is necessary to understand the terminology 
used in morphology. The subject will be considered 
under two heads, morphology of the vegetative organs 
and morphology of the floral organs. 
GENERAL CHARACTERISTICS OF GRASSES 
118. Grasses are included in the natural botanical 
family Poacee or Gramineze.—They are usually distin- 
guished by having long narrow 2-ranked blades, clasping 
sheaths, small greenish flowers collected in a compact 
or open inflorescence. The flowers have no proper peri- 
anth nor floral envelopes, but consist of a pistil and 
usually 3 stamens inclosed between 2 small bracts. 
Further details will be given under the appropriate 
headings. 
There are a few other groups of plants that resemble 
grasses in general appearance. The natural order Poales, 
Graminales or Glumiflore, includes the grasses and sedges 
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