. Botany for agricultural students . Botany. EQUISETALES (HORSETAILS) 435 Some Plants Resembling True Ferns. — Some plants which resemble the True Ferns, although they belong to another group, are the Botrychiums or Moonworts that are common in the woods {Fig. 388). They have an underground stem which sends up leaves that have a finely divided vegetative portion and a spore- bearing portion that much resembles clusters of small Fig. 389. — A section through the tuber-like gametophyte of Botrychium, showing one archegonium and a number of antheridia in the upper surface. X about 10. It
. Botany for agricultural students . Botany. EQUISETALES (HORSETAILS) 435 Some Plants Resembling True Ferns. — Some plants which resemble the True Ferns, although they belong to another group, are the Botrychiums or Moonworts that are common in the woods {Fig. 388). They have an underground stem which sends up leaves that have a finely divided vegetative portion and a spore- bearing portion that much resembles clusters of small Fig. 389. — A section through the tuber-like gametophyte of Botrychium, showing one archegonium and a number of antheridia in the upper surface. X about 10. It is, however, in their gametophyte generation that they differ most from True Ferns. Their gametophytes are tuberous sub- terranean structures bearing the sex organs on the upper surface, and associated with the gametophytes there is always an endophytic Fungus {Fig. 389). Equisetales (Horsetails) In ancient times, as shown by their fossils in coal and other kinds of rock, the Equisetales were very abundant, but the only surviving group is the Horsetails. Their slender stems, often called Joint Grass, are common in meadows, in moist places in the woods and along roadsides. There are about 25 species of Equisetum. There is Equisetum palustre common in swamps, Equisetum pratense and Equisetum arvense common in meadows and fields, and so on. Those growing in meadows and fields are often troublesome weeds. They are widely distributed over North America and also occur on other continents. They range in height from a few inches to several feet. It is reported that one form in the West Indies and Chili sometimes reaches a height of 40 feet, but in our region 3 or 4 feet is a good height. The Equisetums are also called Scouring Rushes because their stems contain silica which is used in making scouring Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectbotany, bookyear1919
