TYPE STUDIES, STSED PLANTS 181 



unequal numbers. Some of the most obvious differences between these 

 relate to the bulb or rootstock or the aerial stem. 



Erythronium belongs to the lily subfamily and Convallaria to the aspara- 

 gus subfamily. 



Give reasons why the lily, dogtooth violet, tulip, trillium, asparagus, lily 

 of the valley, hyacinth, crown imperial, and onion should be classed as of 

 the same family. 



163. Family Ranuncnlacese. Study any obtainable kind of buttercup, 

 discarding such of the following questions as do not apply to the species 

 in hand. 



Ranunculus dbortivus. 



A. Sketch the entire plant. 



B. Describe the root system. 



C. Cut the stem across and note any peculiarity of its structure. 



D. Note the three kinds of leaves, — ' ' root leaves ' ' at the base of the stem, 

 ordinary leaves, and involucral leaves. Sketch one of each kind. 

 What is the advantage of having the upper leaves parted into narrow 

 divisions ? of having the root leaves long-petioled ? 



E. Describe the floral organs. 



1. Make a diagram of a longitudinal section of the flower. How much 

 apparent union of parts of the same or of different circles is there ? 



2. Do all the anthers mature together ? Advantages ? 



3. Do the stigmas and anthers mature together ? Advantage ? 



4. Look for the nectar and nectar glands. What insect visitors occur ? 

 Are the flowers self-pollinated ? 



E. Study a head of mature akenes and describe it. Does seed mature 

 abundantly ? Why cannot this species become a troublesome weed 

 like B. 6uZ6osus or R. acris f 



G. Test the flavor of any species of Ranunculus that you can get, by 

 biting the fresh stem. Explain uses. Does this buttercup seem to 

 be a more or less highly specialized plant than the columbine (Aqui- 

 legia) or the larkspur (Delphinium) of the same family ? In what 

 respects ? 



164. Family Rosacese. Study any kind of rose except the cultivated 

 varieties with double flowers, or any "kind of cherry or plum. 



Rosa humilis. 



A. Describe the height and mode of branching of this rose. Are all 

 specimens equally prickly ? Where do prickles occur ? 



B. Sketch a typical leaf (of five leaflets). How and how much do the leaves 

 vary ? Study a cross section of a leaf with m.p. to find out how 

 much the epidermis protects against excessive transpiration. If con- 

 venient, compare with a greenhouse species, e.g. tea rose. 



