. The Canadian field-naturalist. 1972 DUGLE AND COPPS: POLLEN OF CATTAILS 35 Results and Discussion The presence in Manitoba of Typha angusti- jolia is confirmed, and T. x glauca, its hybrid with T. latifolia is reported for the first time from the province. From sight records and the specimen distribution the taxa were found to be quite common, and the characteristic clones can be recognized from a distance. McDonald (1951) and Yeo (1964) have pointed out that a single seed can result in a large clone of ma- ture plants by vegetative reproduction. There- fore, even a semi-fertile or sterile F
. The Canadian field-naturalist. 1972 DUGLE AND COPPS: POLLEN OF CATTAILS 35 Results and Discussion The presence in Manitoba of Typha angusti- jolia is confirmed, and T. x glauca, its hybrid with T. latifolia is reported for the first time from the province. From sight records and the specimen distribution the taxa were found to be quite common, and the characteristic clones can be recognized from a distance. McDonald (1951) and Yeo (1964) have pointed out that a single seed can result in a large clone of ma- ture plants by vegetative reproduction. There- fore, even a semi-fertile or sterile Fi can spread over a wide area. Apparently Fa plants are quite rare, but backcrosses are not uncommon (Smith 1967) (Appendix). Experimental hybridiza- tions have been very successful (Smith 1967). Hybridization can be expected in nature, as in the Pinawa area flowering time is overlapping although T. latifolia reaches a peak earlier than T. angustifolia. Flowering time varies slightly from clone to clone in all three taxa. Although modern Typha pollen (Figures 1- 6) is entirely anemophilous, Wodehouse (1935) has suggested this may be a derived condition from an entomophilous ancestor because ridges and spines on the exine are characteristic of in- sect pollinated species. There is a trace of but- tressing at the base of the ridges (Figures 1,3, and 6) suggesting an ancestor having a heavily sculptured exine. The single germinal pore is irregular, and the membrane does not expand when the grain is moist. The sculptured exine is not rigid enough to require an expansion furrow. The thin wall of the grains causes them to col- lapse during desiccation (Figures 1,3, and 6), but there is no relation to the pore when they collapse as is common in plants which have a thicker exine. On the single grains, a pattern of parallel ridges may be seen which corresponds to former cell contact areas within the pollen mother cell (Figure 3, especially 3a). Pollen of T. latifolia is shown in Figures
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