PROBLEM 15 11 



4. Make a drawing (diagram) to show liow a bee liclps to 

 pollinate butter and eggs. 



Prohlem 15 : Special directions for the study of some fall 



flowers. (Extra.) i 



The Evening Primrose (Onagra bienriis). — The liabitat pre- 

 ferred by this flower is dry fields, roadsides, or waste places. The 

 yellow flowers are found in long, upright, densely crowded chisters. 

 A flower cluster in which the indivickial flowers have no flower 

 stalks or pedicles, with one main axis to the cluster, is called a sjyike. 

 Notice that young and old flowers and fruits are all on the same 

 cluster. Where are the youngest flowers located in llic cluster? 

 Is there any flower at the end of the main stalk ? Could you deter- 

 mine in advance the length of the flower cluster? Such a cluster 

 is said to be indeterminate. Why? Study a single open flower. 

 Note the^calyx and corolla. Are the parts distinct? How many 

 petals do you find? Notice that there are eight stamens and that 

 the stigma is four-parted. Cut the ovary in cross section, and 

 see how many locules (spaces) there are. 



When a flower has each circle of parts, as the sepals, petals, 

 stamens, and pistils, made up of a certain number of divisions, or 

 when they appear in multiples of that number, the flower is said 

 to be symmetrical. Here we see a very striking example of sym- 

 metry in a flower. 



The chief attraction to insects is the nectar, which is formed in 

 nectar glands at the base inside the slender tubular corolla. In- 

 formation is given to the insects of the contents by a faint, sweet 

 odor. This flower is not visited by many day-flying in.^^cts. 

 Can you determine the names of any that do come by day? At 

 night the flower opens more widely and the scent becomes much 



iTo THE Teacher. — If the work on flowers is taken up in (he sprint:, field work 

 should result in the collection of jack-in-the-pulpit, oak. wilh)w. skunk cahhaKo. 

 grasses, and also many wild flowers which show special achiptations for cross-polli- 

 nation. In the fall butterfly weed, Salvia, turtlehead. and various comi>ositC8 

 show wonderful adaptation. Original investigation on simple i)rohloms of thi.** 

 kind have been found by the writer to he the best means of stimul.ating certain 

 better prepared students to take an abiding interest in this work. Two or thrcr 

 sample investigations are given here that might be used by the student Jis a form in 

 jnaking reports on other flowers. 



