THE GYMNOSPERMS

Chhaya Biswas C B.M. Johri

Springer-Verlag

Narosa Publishing House Contents

Preface vii Acknowledgements ix

1. Introduction 1-11 Antiquity and History 1 Geographical Distribution 4 Cycadales and Ginkgoales 4 Pinaceae 6 Taxodiaceae 6 Cupressaceae 7 Podocarpaceae 7 Araucariaceae 7 Cephalotaxaceae 7 Taxales 8 Ephedrales 8 Welwitschiales 8 Gnetales 8 Characteristic Features 8 Gymnosperms and Pteridophytes 9 Gymnosperms and Angiosperms 10

2. Seed Development 12-19 Microsporangium 12 Microsporogenesis 12 Male Gametophyte 13 Ovule 14 Megasporogenesis 14 Megaspore Wall 15 Female Gametophyte 16 Archegonia 16 Pollination and Fertilization 17 Pollination 17 Fertilization 18 Embryo 19 Seed 19 Seed-Coat 19 Temporal Considerations 19

3. Classification 20-23 xii Contents

4. Progymnospermopsida 24-26 Phylogenetic Considerations of Archaeopteris 25

5. Gymnospermopsida 27 Gymnospermopsida—Cycadophytes (Chapters 6-8)

6. Pteridospermales 28-35 Lyginopteridaceae 29 Lyginopteris oldhamia (Calymmatotheca hoeninghausij 29 Habit 29 Root 30 Stem 30 Leaf 30 Sporangia 33 Seed 33 Phylogenetic Considerations 34

7. Cycadeoidales 36-43 Cycadeoidaceae 38 Cycadeoidea 38 Stem 38 Leaves 38 Reproduction 39 Phylogenetic Considerations 42

8. Cycadales 44-81 Fossil Cycads 44 Nilssonia 46 Baenia 47 Androstrobus manis 41 Living Cycads 47 Root 47 Stem 48 Leaf 49 Reproduction 50 Spermatozoid 51 Ovule 52 Pollen Tube 52 Embryo 54 Chromosome Number 55 Cycadaceae 56 Cycas 56 Contents xiii

Morphology 56 Anatomy 59 Root 59 Stem 59 Leaf 61 Reproduction 63 Male Cone 63 Microsporangium 66 Microsporogenesis 66 Male Gametophyte 67 Megasporophyll 68 Ovule 68 Megasporogenesis 71 Female Gametophyte 71 Archegonium 71 Pollination 73 Fertilization 77 Embryogeny 77 Differentiation of Embryo 79 Seed 79 Chromosome Number 80 Temporal Consideration 80 Phylogenetic Considerations 81 Gymnospermopsida—Gymnosperms of Uncertain Relationship (Chapters 9-12)

9. Caytoniales 82-85 Caytoniaceae—Caytonia 82 Leaf 82 Pollen-bearing Organs 82 Ovule-bearing Organs 84 Phylogenetic Considerations 85

10. Glossopteridales 86-93 Glossopteridaceae—Glossopteris 86 Root 86 Leaf 88 Male Fructifications 88 Ovulate Structures 89 Phylogenetic Considerations 92 11. Pentoxylales 94-97 Pentoxylon 94 Habit 94 xiv Contents

Stem 94 Leaf 95 Microsporangiate Organs 96 Ovulate Cone 96 Phylogenetic Considerations 97 12. Ginkgoales 98-126 Fossil Taxa 98 Ginkgoaceae 100 Ginkgo 100 Morphology 100 Anatomy 104 Root 104 Stem 104 Leaf 105 Reproduction 105 Male Cone 105 Microsporangium 105 Microsporogenesis 107 Male Gametophyte 107 Ovule 107 Megasporogenesis 108 Female Gametophyte 109 Pollination 117 Post-Pollination Development of Male Gametophyte 117 Fertilization 121 Embryogeny 122 Differentiation of Embryo 122 Seed 124 Germination 125 Chromosome Number 125 Temporal Considerations 125 Phylogenetic Considerations 125 Gymnospermopsida—Coniferophytes (Chapters 13-16) 13. Cordaitales 127-136 Corda&taceae-Cordaites 127 Habit 127 Root 127 Stem 128 Leaf 131 Fructifications 131 Cordaianthus concinus 133 Cordaianthus pseudofluitans 133 Phylogenetic Considerations 134 Contents xv

14. 137-143 Morphology 137 Anatomy 138 Reproductive Organs 139 Lebachiaceae 139 Voltziaceae 139 Ullmania 142 Glyptolepis 142 Voltziopsis 142 Phylogenetic Considerations 142 15. Coniferales 144-146 15.1 Pinaceae 146-188 Pinus 146 Morphology 146 Anatomy 150 Root 150 Stem: Shoot Apex 150 Compression Wood 156 Dwarf Shoot 156 Leaf 156 Reproduction 157 Male Cone 157 Microsporangium 158 Pre-meiotic Changes 158 Meiotic Changes 160 Post-meiotic Changes 160 Microsporogenesis 163 Male Gametophyte 166 Female Cone 166 Ovule 166 \ Megasporogenesis 168 Female Gametophyte (First period of growth) 168 Pollination 168 Post-pollination Development of Male Gametophyte 170 Female Gametophyte (Second period of growth) 171 Fertilization 175 Embryogeny 178 Proembryo 178 Differentiation of Embryo 178 Seed 181 Germination 184 Chromosome Number 185 Temporal Considerations 186 15.2 Taxodiaceae 188-202 Cryptomeria japonica 189 xvi Contents

Morphology 189 Anatomy 189 Stem 189 Leaf 191 Reproduction 191 ...--- Male Cone 191 Microsporangium 192 Microsporogenesis 192 Male Gametophyte 192 Female Cone 194 Ovule 194 Megasporogenesis 197 Female Gametophyte 197 Fertilization 199 Embryogeny 199 Diferentiation of Embryo 201 Seed 201 Germination 201 Chromosome Number 201 Temporal Considerations 202

15.3 Cupressaceae 202-221 Biota orientalis 203 Morphology 203 Reproduction 205 Male Cone 205 Microsporangium 205 Microsporogenesis 205 Male Gametophyte 206 Female Cone 207 Ovule 207 Megasporogenesis 207 ( Female Gametophyte 207 Archegonial Complex 209 Pollination 212 Post-pollination Development of Male Gametophyte 212 Fertilization 213 Embryogeny 215 Differentiation of Embryo 217 Seed 218 Germination 218 Chromosome Number 219 Temporal Considerations 221

15.4 Podocarpaceae 221-251 Podocarpus 222 Morphology 222 Contents xvii

Anatomy 222 Root 222 Stem. Shoot Apex 222 Leaf 224 Reproduction 227 Male Cone 227 Microsporangium 227 Microsporogenesis 231 Male Gametophyte 233 Female Cone 234 Ovule 234 Megasporogenesis 236 Female Gametophyte 236 Pollination 237 Post-Pollination Development of Male Gametophyte 239 Fertilization 242 Embryogeny 242 Differentiation of Embryo 245 Seed 248 Germination 250 Chromosome Number 250 Temporal Considerations 251

15.5 Araucariaceae 251-265 Araucaria 252 Morphology 252 Anatomy 254 Stem 254 Leaf 254 Reproduction 257 Male Cone 257 v Microsporogenesis 257 Male Gametophyte 257 Female Cone 259 Megasporogenesis 259 Female Gametophyte 260 Pollination 262 Embryogeny 262 Chromosome Number 265

15.6 Cephalotaxaceae 265-290 Cephalotaxus 265 Morphology 267 Anatomy 268 Leaf 268 Reproduction 270 Male Cone 270 xviii Contents

Microsporangium 270 Microsporogenesis 271 Male Gametophyte 272 Female Cone 273 Ovule 274 - - • Megasporogenesis 278 Female Gametophyte 278 Pollination 282 Post-pollination Development of Male Gametophyte 282 Fertilization 283 Embryogeny 284 Seed 287 Germination 289 Chromosome Number 289 Temporal Considerations 289

15.7 Phylogenetic Considerations of Coniferales 290-291

16. Taxales 292-310 Taxaceae 292 Taxus 292 Morphology 292 Anatomy 293 Stem 293 Leaf 294 Reproduction 295 Male Cone 295 Microsporangium 295 Microsporogenesis 295 Ovule 296 Megasporogenesis 298 Pollination 302 Post-pollination Development of Male Gametophyte 302 Fertilization 303 Embryogeny 304 Seed 308 Germination 308 Chromosome Number 308 Temporal Considerations 309 Phylogenetic Considerations 309

17. Gnetopsida 311

18. Ephedrales 312-342 Ephedraceae 312 Ephedra 312 Contents xix

Morphology 312 Anatomy 313 Root 313 Stem 314 Reproduction 321 Male Strobilus 321 Microsporangium 321 Microsporogenesis 325 Male Gametophyte 327 Female Strobilus 327 Ovule 327 Female Gametophyte 330 Pollination 335 Fertilization 336 Embryogeny 337 Seed 338 Chromosome Number 341 Temporal Considerations 341 19. Welwitscniales 343-365 Welwitschiaceae 343 Welwitschia 343 Morphology 343 Anatomy 346 Root 346 Stem 347 Leaf 349 Reproduction 352 Cone Bracts 352 Male Strobilus 354 Microsporangium 355 ; Male Gametophyte 355 Female Strobilus 356 Megasporogenesis 356 Female Gametophyte 356 Pollination 359 Post-pollination Development of Male Gametophyte 360 Fertilization 360 Embryogeny 360 Seed 364 Germination 364 Chromosome Number 365

20. Gnetales 366-404 Gnetaceae 366 Gnetum 366 xx Contents

Morphology 366 Anatomy 366 Root 366 Stem 367 Leaf 375 Reproduction 378 Male Strobilus 378 Microsporangium 378 Microsporogenesis 381 Male Gametophyte 383 Female Strobilus 384 Ovule 384 Megasporogenesis 389 Female Gametophyte 389 Pollination 391 Fertilization 393 Embryogeny 396 Seed 400 Germination 402 Chromosome Number 402 Temporal Consideration 403

21. Phylogenetic Considerations: Ephedra, Welwitschia and Gnetum 405-407

22. In Vitro Experimental Studies 408-439 Vegetative Tissues and Organs 408 Microspore and Male Gametophyte 411 Female Gametophyte 413 Embryo 423 Biotechnolgy 433 Somatic Embryogenesis 433 Genetic Transformation 436 Protoplast Culture 436 Micropropagation 437

23. Economic Importance 440-456 General Aspects 440 Woods 441 Araucariaceae 442 Cupressaceae 442 Pinaceae 443 Podocarpaceae 444 Taxodiaceae 445 Taxaceae 445 Ginkgoaceae 445 Contents xxi

Paper and Board 445 Resins 446 Hard Resins 447 Copal 447 Kauri Copal 447 Manila Copal 447 Amber 448 Sandarc 448 Oleoresins 449 Turpentine 449 Canada Balsam 450 - Venice Turpentine 450 Tannins 451 Essential Oils 451 Fatty Oils 451 Food Supplements 452 Pharmaceuticals 454

24. Concluding Remarks 457-459 Seasonal Changes in Secondary Growth 457 Population and Wood Requirement 457 Pollution 458 Symbiosis 458 Reproductive Biology 458 Pollen Biology 459 Life History 459

References 460-489 Index 491-494