CHAPTER VII. THE FLOWER 

 I. DISSECTION OF TYPES WITH SUPERIOR OVARY 



Material. — For monocotyls, any flower of the lily family, such as 

 tulip, dogtooth violet {Erythronium) , trillium, star-of-Bethlehem, yucca, 

 bear's grass, and the like. The large garden lilies make particularly good 

 examples, but they are for the most part spring bloomers. For autumn, 

 spiderwort (Tradescantia) , arrow grass (SagiUaria), or late specimens of 

 colchicimi and tiger lily may be used. Any of these will meet the essential 

 conditions of the analysis given in the text, but care should be taken not to 

 select for this exercise lily-like flowers of the iris and amaryllis families, 

 which have the ovary inferior. 



For examples of hypogynous dicotyls, flax, linden, pinks, corn cockle, 

 wood sorrel, poppies, tomato blossoms, and other common flowers can 

 usually be obtained without difficulty. In autumn, the geraniums so 

 largely cultivated for ornament will meet all the conditions of the analysis. 

 Specimens of the cress family — wallflower, cabbage, mustard, turnip — 

 can generally be found every^vhere and at all seasons, and they possess 

 the advantage of having their flowers throughout the order put up on so 

 nearly the same pattern that a description of one species will answer, even 

 in details, for the rest. 



For sympetalous specimens of the hypogynous type, hyacinth, lily of 

 the valley, bearberry, huckleberry, or other equivalent forms may be 

 used. 



Appliances. — A compound microscope may be needed for examining 

 minute objects, such as pollen grains and ovules; but for all other pur- 

 poses, a good hand lens, with the pupil's ordinary laboratory equipment 

 of drawing-materials, notebook, and dissecting needles, will be sufficient 

 for the studies outlined in this and the four succeeding sections. 



211. The floral envelopes. — Make a sketch of your 

 specimen flower from the outside. Is it solitary, or one of a 

 cluster? If the latter, refer to 160-162 and tell the nature 

 of the cluster. Notice the color ; is it conspicuous enough 

 to attract attention or not? Can this have anything to do 

 with its clustered or solitary position? Label the head of 

 the peduncle that supports the flower, receptacle; the outer 



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