SEED DISPERSAL

W. J. BEAL, M.S., PH.D.

GINN & COMPANY

PREFACE.

This little book is prepared with the thought of helping young botanists and teachers. Unless the reader has followed in detail, by actual experience, some of the modes of plant dispersion, he can have little idea of the fascination it affords, or the rich rewards in store for patient investigation.

A brief list of contributions to the subject is given; but, with very few exceptions, the statements here made, unless otherwise mentioned in the text, are the results of observations by the author.

I am under obligations for suggestions by my colleague, Prof. W. B. Barrows; my assistant, Prof. C. F. Wheeler; and a former instructor of botany, L. H. Dewey, now of the United States Department of Agriculture. B. O. Longyear, instructor in botany, with very few exceptions, has made the drawings.

  AGRICULTURAL COLLEGE, MICHIGAN.

CONTENTS.

CHAPTER I.—HOW ANIMALS GET ABOUT.

  1. Most of the larger animals move about freely
  2. Some animals catch rides in one way or another

CHAPTER II.—PLANTS SPREAD BY MEANS OF ROOTS.

  3. Fairy rings
  4. How nature plants lilies
  5. Roots hold plants erect like ropes to a mast
  6. How oaks creep about and multiply

CHAPTER III.—PLANTS MULTIPLY BY MEANS OF STEMS.

  7. Two grasses in fierce contention
  8. Runners establish new colonies
  9. Branches lean over and root in the soil
10. Living branches snap off and are carried by water or wind

CHAPTER IV.—WATER TRANSPORTATION OF PLANTS.

11. Some green buds and leaves float on water
12. Fleshy buds drop off and sprout in the mud
13. Seeds and fruits as boats and rafts
14. Bits of cork around the seeds prevent them from sinking
15. An air-tight sack buoys up seeds
16. Fruit of basswood as a sailboat, and a few others as adapted to the water

CHAPTER V.—SEEDS TRANSPORTED BY WIND.

17. How pigweeds get about
18. Tumbleweeds
19. Thin, dry pods, twisted and bent, drift on the snow
20. Seeds found in melting snowdrifts
21. Nuts of the basswood carried on the snow
22. Buttonwood balls
23. Seeds that tempt the wind by spreading their sails
24. Why are some seeds so small?
25. Seeds with parachutes
26. A study of the dandelion