The Ratios of Clockwise and Counterclockwise Spirality Observed in the Phyllotaxy of Some Wild Plants


H. A. Allard

Additional Authors:


March – 1951


Spirality, Phyllotaxy, Nicotiana, tabacum, rustica, wood nettle, Laportea, canadensis, Utricaceae, smartweed, Polygonum, hydropiper, Polygonaceae, lamb’s quarters, Chenopodium, album, Chenopodiaceae, pokeweed, Phytolacca, americana, Phytolaccaceae, garlic mustard, Alliara, officinalis, crucifera, yarrow, Achillea, millefolium, compositae, goldenrod, Solidago, altissima, serotina, Compositae, Alnus, serrulata, Betulaceae, staghorn, sumac, Rhus, typhina, smoot sumac, glabra, Anacardiaceae, tree-of-heaven, Ailanthus, altissima, Swingle, Simaroubaceae, wild senna, Cassia, hebecarpa, Leguminosae

During a study of the ratios of clockwise and counterclockwise spirality occurring in the phyllotaxy of several varieties and strains of Nicotiana tabacum L., and N. rustica L., some attention was given to several wild plants of other families, including both herbaceous and woody types. Among the herbaceous plants were the following: Wood nettle, Laportea canadensis (L.) Gaud. Urticaceae; smartweed, Polygonum hydropiper (?), Polygonaceae; lamb’s quarters, Chenopodium album L., Chenopodiaceae; pokeweed, Phytolacca americana L., Phytolaccaceae; garlic mustard, Alliaria officinalis Andrz., cruciferae; yarrow, Achillea millefolium L., compositae; goldenrod, Solidago altissima L., and S. serotina Ait., Compositae.