| BEN |
| BOTANICAL ELECTRONIC NEWS |
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| ISSN 1188-603X |
| No. 196 June 23, 1998 | aceska@victoria.tc.ca Victoria, B.C. |
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The NPSBC Native Plant Society of British Columbia held its second Annual General Meeting on Saturday, May 23rd at the Penticton Lakeside Resort and Conference Centre in Penticton, BC. The meeting introduced two new projects of the Society: an Atlas of British Columbia Flora that will involve members of the Society and the public in surveying native plants and habitats in regions throughout the province; and Ethical Use Guidelines and Principles.
The Atlas project was introduced by the Biodiversity/Research Committee. Later, Al Oliver of the Agriculture and Agri-Food Canada Food Inspection Agency spoke on the issue of ethics using the impact on native plant nurseries and habitats from gypsy moth infestation as an example. There were also a number of exhibits by businesses and organizations with a related interest in native plants and habitats.
During the business portion of the Annual General Meeting, four new directors were elected to the Board of fifteen members including Brian Compton of Vancouver, Malcolm Martin of Vernon, Brenda Ramsay of Terrace and Claudia Schaefer of Vancouver; four other directors were re-elected to the Board and eight continued for the second year of their two-year terms.
The current Executive will continue for another year, with Douglas Justice, New Westminster as President.; Tom Wells, Delta as Vice-President; Ross Waddell, Vancouver as Secretary; and Sylvia Mosterman, Chilliwack as Treasurer. Other continuing directors include Adolf Ceska, Victoria; Theresa Duynstee, Delta; Verna Miller, Spences Bridge; John Olafson, Victoria; Giles Stevenson, Duncan; Paulus Vrijmoed, Langley; and David Williams, Kamloops.
Prior to the meeting, the Society held a popular workshop on "The Identification of Grasses" in cooperation with the Ministry of Forests in Penticton. The workshop was led by Board member, Dr. Adolf Ceska of the BC Conservation Data Centre in Victoria, assisted by Oluna Ceska. This two-day event was one of the most requested in the Society's recent membership survey.
The attendees spent Saturday afternoon visiting the Ornamental Gardens at the Pacific Research Centre of Agriculture and Agri-Food Canada in Summerland. That evening, the Annual Dinner of the Society featured Dr. Roy L. Taylor, Executive Director of the Rancho Santa Ana Botanic Garden speaking on "California Native Plant Initiatives - A Model for British Columbia". Dr. Taylor, who is the former Director of the University of British Columbia Botanical Garden, is an internationally recognized expert on the flora of the Queen Charlotte Islands.
The weekend ended with two field trips in the South Okanagan Region: Adolf and Oluna Ceska led a trip to the grassland bluffs at Vaseux Lake; and Harold Baumbrough hosted members at the Nature Trust in Naramata. The Society will now focus on the implementation of the Atlas of British Columbia Flora Project and solicits the interest of persons from throughout the province who wish to become involved with this project. Dr. Bob Maher and the Centre for Environment and Information Management (CEIM) of the Royal Roads University in Victoria, expressed the interest to co-ordinate this project.
Individual membership fees are $20 per year (applications should be sent to NSPBC, 2012 William Street, Vancouver, B.C., V5L 2X6) and include subscriptions to MENZIESIA, a newsletter published 3-4 times a year.
[In the cover letter to this article, Dr. Garbary wrote: "I tried to make this ms as simple as possible in terms of jargon and taxonomic detail. The only assumption that I have made is that readers have some familiarity with the language of phylogenetic analysis." I found a nice glossary of terms used in cladistics on the following web page:
and a good introduction to cladistics is at
A. Ceska]
The identification of the primary lineages of land plants and their phylogenetic relationships is a fundamental question in plant evolutionary biology (Graham 1993, Kenrick and Crane 1997). A primary aspect of this problem involves the three groups of bryophytes (i.e., hornworts, liverworts and mosses) and their relationships to each other and to remaining lineages of terrestrial plants. These bryophyte groups are central to the problem because of conflicting interpretations regarding whether or not liverworts or hornworts are the sister group to remaining land plants, and whether or not mosses plus liverworts form a monophyletic lineage. Recent phylogenetic interpretations involving hornworts (Anthocerotopsida) have led to two widely accepted points:
Here we review the current state of our knowledge on hornwort phylogeny, and their relationships with other land plants. Monophyly of land plants is an assumption of this essay.
The phylogenetic trees of Mishler & Churchill (1984, 1985) provided a seminal contribution to interpretations of land plant evolution. The central feature of their cladograms was the paraphyletic nature of the bryophytes with three lineages occurring in sequence (liverworts, hornworts and mosses) at the base of the land plant clade (Figure 1). Two consequences of this arrangement were that the liverworts were the sister group of all other land plants and that mosses were the sister group to vascular plants (and as was suggested by Kenrick & Crane 1991, 1997 - the protrachiophyte grade).
Although the Mishler & Churchill scheme has been widely reproduced and accepted, several conflicting interpretations of hornwort relationships have been proposed subsequent to their groundbreaking study. Garbary et al. (1993) used male gametogenesis and sperm architecture to base phylogenetic analyses of land plants. The premise behind utilization of these characters is that male reproductive development provides an unparalleled suite of unequivocal characters that are truly homologous across all land plants with flagellated sperm. This study suggested that all bryophyte groups formed a monophyletic assemblage that was sister to remaining vascular plants (Figure 2). The only counter intuitive result was the placement of Selaginella basal on the bryophyte clade. Subsequent analyses of Selaginella based on new data that emphasized development rather than mature sperm morphology has placed Selaginella in a more intuitively correct position within a lycophyte assemblage (Maden et al. 1997, Renzaglia et al. 1998). The position of hornworts external to a moss plus liverwort assemblage is a primary feature of the phylogenetic hypothesis based on male gametogenesis.
More recent approaches to this problem have included a number of molecular sequence studies and a more comprehensive analysis of morphological, developmental and ultrastructural features across a wide range of bryophyte, lycophyte and pteridophyte assemblages (Hedderson et al. 1996, 1998; Malek et al. 1996; Garbary & Renzaglia 1998). The pattern of relationships resolved in these studies suggests that hornworts are the basal lineage of land plants. In addition, these studies suggest that mosses and liverworts form a monophyletic group that is the sister-clade to vascular plants (Figure 3). The molecular studies use the 18s gene for rRNA and the cox3 mRNA. Conflicting conclusions are derived from sequences of the chloroplast gene for rbcL by Lewis et al. (1997) where hornworts are resolved as the sister group to vascular plants.
In summary, several studies are congruent in indicating the basal position of hornworts in land plants, as well as the monophyly of a moss plus liverwort clade. Although these conclusions must be regarded as tentative pending more comprehensive taxon sampling for both molecular and non-molecular characters, the overall evidence seems to be away from the Mishler and Churchill hypothesis, and to a more fundamental role for hornworts in interpretations of land plant phylogeny. Clearly, the hypothesis that hornworts are the most ancient extant lineage of land plants remains a viable option that requires further testing and exploration.
References:
Figure 1. Mishler and Churchill model with liverworts as the sister group to all other land plants.
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Figure 2. Revised hypothesis based on male gametogenesis with bryophytes as monophyletic assemblage.
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Figure 3. New model with hornworts as sister group to all other land plants and with mosses and liverworts as monophyletic.
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The material we found clearly belongs to Alnus rubra, adding a new native tree species to the flora of Montana!
Alnus rubra is a coastal species familiar to botanists west of the Coast Ranges and Cascades but relatively rare inland. The Montana stations represent the easternmost limits of the species' range. Red alder is occasional in northern Idaho, where it is suspected of hybridizing with Alnus incana ssp. tenuifolia (Lorain 1988), a phenomenon which may also be occurring in the Montana populations.
Red alder joins a suite of other coastal vascular plants, mosses and lichens which are disjunct in the "inland wet belt" stretching from west-central Idaho and western Montana north into central B.C. (and it has been a very wet belt this year). These species are particularly conspicuous in the valleys along the Clark Fork and Kootenai Rivers and in the Cabinet and Purcell Mountains of northwest Montana. If the Pacific Northwest is ever blessed with a distribution atlas for our flora it would be interesting to gauge the participation by percentage of various phytogeographic elements -- e.g., coastal, interior northwest, boreal and cordilleran -- in these local floras and compare them with coastal areas. But that will have to await better budgets!
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