What is the world's most common plant or weed?

Some people have suggested that BRACKEN FERN (Pteridium) is the world's most common plant. Plankton, moss, or algae might also qualify, oceanic cyanobacteria being the world's most numerous plants by far. Seagrass, which are flowering plants, are another very common plant. Or the common reed (Phragmites australis) which is sometimes indigenous and sometimes a weed.

Many of the following plants are highly invasive weeds capable of making extinct entire communities of native plant species. Some of these plants have a natural range in which the plant communities or even plants themselves are threatened by human impact, and by the outside influences that humans create. These plants may also on occasion be controlled within their natural range, to stop them from outcompeting other plants that have been endangered by human-induced encroachment (such as the introduction of foreign plants).

I have made a list of 100 plants using some COMMON, and some scientific names. one of these plants is probably "the world's most common plant".

1. Pteridium.

2. Nephrolepis cordifolia.

3. Phragmites australis.

4. Cyperus rotundas.

5. Ehrharta erecta.

6. Paspalum.

7. Digitaria.

8. PAMPAS GRASS.

9. LOVEGRASS.

10. WHEAT.

11. CORN.

12. RICE.

13. Lolium perenne.

14. Cynodon dactylon.

15. Imperata cylindrica.

16. MAPLE.

17. PRIVET.

18. Camphor laurel.

19. Pinus radiata.

20. Pinus sylvestris.

21. Quercus robur.

22. BIRCH.

23. SPRUCE.

24. BEECH.

25. FIR.

26. JUNIPER.

27. Ulmus glabra.

28. Ficus.

29. Salix alba.

30. Populas alba.

31. Coreopsis.

32. Gazania rigens.

33. Tradescantia fluminensis.

34. BAMBOO.

35. Typha.

36. WATERCRESS.

37. Salvinia molesta.

38. Persicaria.

39. WATER HYACINTH.

40. ALLIGATOR WEED.

41. Coffea.

42. Nicotiana.

43. Camellia sinensis.

44. Rumex.

45. BANANA.

46. BLACKBERRY.

47. Acacia saligna.

48. Celtis.

49. Lantana.

50. Hydrocotyle bonariensis.

51. PRICKLY PEAR.

52. AFRICAN OLIVE.

53. PASSIONFRUIT.

54. GRAPEVINE.

55. ASPARAGUS.

56. Ricinus communis.

57. Solanum.

58. POTATO/ YAM.

59. DANDELION.

60. Euphorbia peplus.

61. Oxalis ssp.

62. CHICKWEED.

63. DODDER LAUREL.

64. Cardiospermum grandiflorum.

65. HONEYSUCKLE.

66. Ipomoea cairica.

67. Ipomoea indica.

68. KUDZU.

69. Xanthium occidentale.

70. Salpachroa origanifolia.

71. Acetosa sagittata.

72. Anredera cordifolia.

73. Buxus.

74. Bouganvillea sp.

75. Acacia saligna.

76. Celtis.

77. Lantana.

78. COMMON HAWTHORN.

79. Leptospermum lavigatum.

80. Pittosporum undulatum.

81. Senna pendula.

82. Ochna serrulata.

83. Cestrum parqui.

84. Cytisus scoparius.

85. Agapanthus.

86. Iris.

87. Freesia hyb rid.

88. FLEABANE.

89. Sonchus Oleraceus.

90. Ageratina adenophora.

91. Chenopodium album.

92. Amaranthus hybridus.

93. Plantago lanceolata.

94. Brassica fruticulosa.

95. Cirsium arvense.

96. Lactuca serriola.

97. Epilobium.

98. Senecio.

99. Aster subulatus.

100. Bidens Pilosa.

Some of these are the worlds most common plants because they evolved particularly opportunistic characteristics. And some because of mankind's necessity, naivety, ignorance or contempt. Most are spread by wind, water, insects, birds, and other animals.