Studies of Selected Spermatophytes. 231 



Now compare the poplars and willows and tabulate their 

 similarities and dissimilarities so as to bring out the grounds 

 for classifying them in the same family but in different 

 genera. 



Ranunculus abortivus. 



State the character of the habitat in which this plant 

 grows. Draw its different kinds of leaves from base to 

 apex, including the leaves of the involucre subtending the 

 flowers. What advantage is given to the lower leaves by 

 their long petioles ? Draw a flower so as to show clearly 

 sepals, petals, stamens, and pistils. Study a longitudinal sec- 

 tion through the center of a flower, and make a longitudinal 

 diagram according to the directions on page 153. Do the 

 anthers all dehisce at the same time ? Do stigmas and 

 anthers mature at the same time ? Can nectar be found ? 

 Is the pollen of a nature to be carried by the wind? 

 Would self pollination probably take place ? Study a 

 species of Myosurus in the same manner. How does it 

 differ from, and what has it in common with Ranunculus ? 

 What advantages do you see in the elongation of that part 

 of the receptacle which bears the pistils ? Would this 

 habit insure the self pollination of all the pistils ? 



Delphinium. (Obtainable species.) 



Note the habitat, habit, and ' size of the plant. Draw a 

 typical leaf. Draw an inflorescence showing correctly the 

 position of the flowers and the direction of the spur. Dis- 

 sect a flower and identify the different parts. Discover 

 what purposes the irregularities in the parts serve. (For 

 suggested diagram of the flower, see Fig. 79.) Get a good 

 understanding of the positions of the different parts in 

 flowers of various ages from bud to withering flower. 



