Spores of Lycopodium and Selaginella of North Pacific America
Heusser CJ and Peteet DM. 1988. Spores of Lycopodium and Selaginella of North Pacific America. Canadian Journal of Botany. 66(3):508-525
A morphological basis for distinguishing spores of the northwest species is constructed. This helps to provide background for a regional account of the Quaternary phytogeographical relations of Lycopodium and Selaginella. The study area covers the Pacific slope from northern California to Western Alaska. Morphological descriptions and keys apply to spores of eight species of Lycopodium (L. alpinum, L. annotinum, L. clavatum, L. complanatum, L. inundatum, L. obscurum, L. selago, and L. sitchense) and seven species of Selaginella (S. densa, S. douglasii, S. oregana, S. selaginoides, S. sibirica, S. wallacei, and S. watsonii). Spores are radiosymmetric, heteropolar, tetrahedral, and trilete. The most workable characters of use in identification of spores of Lycopodium are type sculpture (mostly reticulate but also foveolate and rugulate) and the presence, continuity, and absence of sculpture on proximal and distal faces. Spores of Selaginella are distinguished by the presence or absence of a perine, perine thickness, microsculpture, and appearance of cristae. Modern, Holocene, and Pleistocene distribution records of L. selago and S. selaginoides are reviewed for the purpose of developing the Quaternary history of Lycopodium and Selaginella in North Pacific America. They illustrate the importance of refugia in Washington, the Queen Charlotte Islands, and Japan — eastern Asia, which were noteworthy distribution centers during and following Wisconsin glaciation.
- Type
- Journal Article
- Authors
- Heusser, Calvin; Peteet, Dorothy
- Units
- GLAC
- Keywords
- Alaska, Fossil record, Lycopodium, North Pacific America, Northern California, paleoenvironments, phytogeographical relations, Quaternary, Selaginella, spores