RELATED FORMS 
337 
FIELD TRIP TO GREENHOUSE OR 
WOODS TO STUDY FERNS 
Note the color of the plants, the character¬ 
istic fern leaf with its stipe or central stalk, 
its pinnae or leaflets, and also the method of 
unrolling from the base to the tip. Note the 
fruiting dots (sori) on the back of the leaves. 
In what kind of soil are ferns found? Do 
they grow best in the sun or in the shade? 
Do leaves remain green during the winter? 
Note the underground stem and its roots. 
Look for buds and young leaves. Note the 
forked veins. 
Figure 309. —Sporophyll 
of Equisetum (enlarged). 
A, sporophyll; B, spo¬ 
rangia ; C, spores. 
LABORATORY STUDY 
Examine the cross section of a stem and note the different kinds of 
tissue. Draw and label: (1) epidermal tissue on the outside; (2) mechani¬ 
cal , dark brown tissue in masses near the center; (3) conductive tissue , 
large openings; (4) funda¬ 
mental tissue filling the rest of 
the space. With a microscope 
examine the epidermis on the 
under side of the leaf, noting 
the shape of the cells and the 
stomata. Pull off a bit of 
the epidermis and try to dis¬ 
tinguish the green guard cells. 
Examine a sorus with low 
power of the microscope and 
see how it is made up of 
sporangia on stalks. 
287. Related Forms.— 
Club mosses, horsetails, 
and selaginella (se-laj-m- 
el'la) are plants which 
belong to the fern group. 
Club mosses bear their 
spores in a spike on 
scales which are modified 
Figure 310.— Equisetum. 
A, collar of teeth ; B, node; 
C, internode ; D, branch. 
