CHAPTER XI 



MORPHOLOGY OF THE VEGETATIVE ORGANS 



Morphology 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 Poaceae or Gramineae. — 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 Glumiflorae, includes the grasses and sedges 



(95) 



