Wild-Flower Study 549 



parallel veins and ruffled edges. They are dull olive green in color, much 

 darker than the stems; in texture they are very thin, papery, and so 

 shining as to give the impression of beingVarnished. No land plants have 

 such leaves; they remind us at once of kelp or other seaweeds. The 

 leaves are scattered along the stems, by no means thickly, for water 

 plants do not seem to need profuse foliage. 



In blossom time the pondweed shows its real beauty. The stems grow 

 and grow, like Jack's bean stalk, and what was a bed of leaves on the pond 

 bottom suddenly changes into a forest of high plants, each one standing 

 tall and straight and with every leaf extended, as if its stems were as 

 strong and stiff as iron wood ; but if a wave disturbs the water the graceful 

 undulations of the plant tell the true story of the pliant stems. There is 

 something that arouses our admiration when we see one of these pond- 

 weeds grown so straight and tall, often three or four yards high, in order 

 to place its little, greenish-brown flower-head above the water's surface. 



We have spent hours looking down into such a 

 submerged forest, dreaming and wondering about 

 the real meaning of such adaptations. 



Although the stem is flexible, the somewhat 

 curved, enlarged portion of it just below the flower- 

 head is rigid; it is also more spongy than the lower 

 part of the stem and is thus fitted to float the flower. 

 The flower itself is one of the prettiest sights that 

 nature has to show us through a lens. It is a Mal- 

 tese cross, the four reddish stigmas arranged in a 

 solid square at the center; at each side of this cen- 

 tral square is a double-barrelled anther, and outside 

 of each anther is a queer, little, dipper-shaped, green 

 sepal. When the anthers open, they push away 



i, Flou'cr of a pond-^ rom ^ ne stigmas and throw their pollen toward the 

 weed enlarged, ' ca rly stage, outside. There may be thirty or more of these 

 2, Same at later stage. tiny, cross-shaped flowers in one flower-head. In 

 the bud, the cup-shaped sepals shut down closely, exposing the stigmas 

 first, which would indicate that they ripen before the pollen is shed. The 

 pollen is white, and is floated from plant to plant on the surface of the 

 water; often the water for yards will be covered with this living dust. 



LESSON CXXXIII 

 PONDWEED 



Leading thought The pondweed lives entirely below the water; at 

 blossom time, however, it sends up its flower stems to the surface of the 

 water, and there sheds its pollen, thus securing cross-pollenation. 



Method As this is primarily a lesson that relates to geography, the 

 pondweed should be studied where it is growing. It may be studied in 

 the spring or fall, and the pupils asked to observe the blossoming whic> 

 occurs in late July. After the pupils have seen where it grows, the plants 

 themselves may be studied in an aquarium, or by placing them in a pail or 

 basin of water. There are confusing numbers of pondweeds but any of 

 them will do for this lesson. The one described in the Teacher's Story is 

 probably P. perfoliatus. 



