. The Canadian field-naturalist. The Canadian Field-Naturalist Vol. 99. Figure 1. Typical inflorescence of Chamaepericlymenum canadense showing the four white involucral bracts and about 25 individual flowers of which some six have not yet popped open. Photo courtesy Mosquin Bio-Information Limited. nism in Cornussuecicum L. although the latter species was also included in his flora. The inflorescence oiChamaepericlymenum is com- prised of four white showy involucral bracts sur- rounding a few to several dozen small, relatively inconspicuous flowers (Figure I). The true petals are a very light
. The Canadian field-naturalist. The Canadian Field-Naturalist Vol. 99. Figure 1. Typical inflorescence of Chamaepericlymenum canadense showing the four white involucral bracts and about 25 individual flowers of which some six have not yet popped open. Photo courtesy Mosquin Bio-Information Limited. nism in Cornussuecicum L. although the latter species was also included in his flora. The inflorescence oiChamaepericlymenum is com- prised of four white showy involucral bracts sur- rounding a few to several dozen small, relatively inconspicuous flowers (Figure I). The true petals are a very light greenish yellow to nearly white in colour. The filaments and anthers are also very light coloured. However, the ovary, style and stigma are a very dark purple and provide striking miniature contrast points in the inflorescence. In the Banff area the number of flowers in each inflorescence varied from 8 to 15. The pollination mechanism of Chamaepericlyme- num is so intrinsically interesting as well as unique in the plant kingdom that 1 feel it would be worthwhile to record here a brief description of how the discovery was made. This account is based on plants growing near Altrude Creek about one mile south of Mt. Eisenhower Junction in Banff National Park. Lying stomach down on the forest floor looking through a microscope, I began to examine the plants searching for a series of flowers in various stages of maturation. Normally, it is relatively easy to assemble such a sequence ranging from young buds to flowers that are very old and in a state of senescence. But each flower of C. canadense was either still in the bud stage or completely open with the petals very strongly reflexed outwardly or downward. In all open flowers the anthers extended upward, well above the tip of the stigma, and were empty of pollen. While the absence of flowers in the process of opening was puzzling, I attributed it at first to local environmental factors and continued to examine more inflorescences.
Size: 1774px × 1409px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorottawafieldnaturalistsclub, bookcentury1900, bookcolle
