| BEN |
| BOTANICAL ELECTRONIC NEWS |
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| ISSN 1188-603X |
| No. 286 April 30, 2002 | aceska@freenet.victoria.tc.ca | Victoria, B.C. |
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My computer people had some problem with majordomo, which is used to distribute BEN. The BEN-L list became erratic and open to hackers. In order to protect BEN subscribers, I unsubscribed everyone from the list. When the problem was fixed, I resubscribed you all. What you received is the standard "welcome" message that is sent to all new subscribers. I also used this opportunity to clean up and remove all outdated addresses. I could have added to the welcome message to tell you this, but I would first have had to figure out how to do that, and was too lazy to find out. I apologize for the confusion. Also, all messages sent out from BEN-L mailing list will now have [ben-l] in front of the subject.
Joint meeting of British Columbia and Washington botanists will take place at Selkirk College in Castlegar, B.C. from June 16 to June 19, 2002. More information and registration forms are available at
The registration is in full swing. We have to know how many people are coming by May 15. After that date the registration fee will go up to CDN$80.00 (or US$50.00) and you may not get in. Please, register now, if you want to come.
A new species of the invasive aquatic weed Spartina has been found at the west end of Grays Harbor, Washington state's only coastal, deep-water port. The new species, known as Spartina densiflora Brongn., was found recently by Les Holcomb, a state Department of Fish and Wildlife scientific technician, while he was performing a noxious weed survey.
Dr. Don Strong of the University of California at Davis in December confirmed the species through genetic identification. The infestation covers more than one-tenth of an acre near Point Brown at the southern tip of the Ocean Shores peninsula.
Spartina is an invasive cordgrass that is taking over tideflats in Puget Sound and coastal Washington, altering natural fish and shellfish habitats and excluding native vegetation.
The newly discovered species poses eradication challenges similar to the three other species of Spartina that infest more than 5,000 acres spread over 20,000 acres of private and public tidelands in Western Washington. As with other members of Spartina, this species can degrade habitat for shorebirds, fish, and wetland plants. It could cause damage to the shellfish industry if it spreads. The first species of Spartina introduced to the Pacific Northwest was S. alterniflora Loisel., first introduced to the Pacific Northwest from the East Coast in the late 1880's as a packing material on ships. By the 1950s, oyster growers in Willapa Bay were worried and asked the Willapa National Wildlife Refuge staff to look into what the plant was doing to the bay. At that time there were less than 400 acres of Spartina. Today 10 counties in Western Washington have one or more infestations of Spartina alterniflora, with the largest infestations in Willapa Bay and in Island, Snohomish, and Skagit counties.
Employees from the state departments of Agriculture and Fish and Wildlife last month started to remove or destroy seed heads of the Spartina densiflora and survey north and south bay areas of Grays Harbor in an attempt to find any other pockets of the weed.
Efforts to combat the noxious weed are based on an integrated weed management approach, which includes hand pulling, digging, mowing, covering with fabric or plastic, spraying with herbicides, and biological control.
The aquatic cordgrass weed is native to Chile and has previously been found in parts of California. Scientists are in the process of identifying another cordgrass sample from north Puget Sound that may also be Spartina densiflora. "This new Spartina species grows like a bunchgrass, is very distinctive, and doesn't break off at the base," said Clinton Campbell, pest program manager at the state Department of Agriculture. "We're investigating how the plant arrived in Washington, but meanwhile we need to act promptly to control this newly discovered infestation."
Scientists are searching for a more sophisticated understanding of the dynamics of the Spartina invasion and for safe tools to control the weed. Bio-intensive integrated pest management, an approach to weed control based on an evolving and improving understanding of the target weed and its natural pests, is seen as the path to Spartina control in Washington. Among the partners working with the Department of Agriculture to control Spartina are private landowners; county noxious weed boards; tribes; the state departments of Fish and Wildlife, Natural Resources, and Ecology; the State Parks and Recreation Commission; the U.S. Fish and Wildlife Service; the University of Washington; Washington State University; and Evergreen State College.
Dense-flowered cordgrass (Spartina densiflora Brongn.), native to the coasts of Chile and Argentina, was first introduced to the U.S. at Humboldt Bay, California in the 1850s (Spicher and Josselyn 1985). A lumber trade existed between Chile and Humboldt Bay at that time, and the species was probably transported as ballast. Between 1850 and the present, salt marsh in Humboldt Bay was reduced to 10% of its original extent, primarily by conversion to agriculture. At the same time, S. densiflora has invaded 94% of the remaining salt marsh. Spartina densiflora became established in San Francisco Bay in 1976 as part of a restoration project, when it was transplanted from Humboldt Bay (Spicher 1984). It has since spread invasively and along with Spartina alterniflora Loisel. it is the focus of a major, estuary-wide control effort. Recently, occurrences of Spartina densiflora have also been detected at Tomales Bay.
Spartina densiflora is perennial that spreads by seeds and short tillers. It flowers from April to August in California, with seed set from August to September. It does not undergo complete dormancy in winter months, unlike the native components of northern California salt marsh, which accounts in part for its competitiveness (Kittelson and Boyd 1997). Seedling survival is apparently higher in wetter years. Spartina densiflora is found between 5.9 and 7.9 MLLW on Humboldt Bay (Eicher 1987). Its prevalence in between 6.2 and 7.3 MLLW has resulted in a near monoculture at those elevations. Salt marsh vegetation in Humboldt Bay has been classified into three types that are roughly controlled by tidal elevation: low-elevation Salicornia marsh (5 species), mid-elevation Spartina marsh (10 species) and high elevation Mixed marsh (22 species) (Eicher 1987). Although S. densiflora was believed to be spreading only in newly disturbed mid-elevation marshes (Kittelson and Boyd 1997), a recent study showed that it has been dramatically increasing in high elevation mixed marsh as well (Pickart 2001). The high elevation marshes are the most diverse and support two rare salt marsh hemiparasites, Humboldt Bay owl's clover (Castilleja ambigua subsp. humboldtiensis) and Point Reyes bird's beak (Cordylanthus maritimus subsp. palustris). Given that so much of Humboldt Bay has been invaded, conservationists are focusing on the possible prevention of further spread into high elevation salt marsh. In addition, the benefit of creating new low and mid-elevation marshes through restored tidal action is being questioned by some because of the likelihood of resulting Spartina densiflora dominance.
References:
[See also: http://www.spartina.org/species/spartina-densiflora.pdf]
Snowdrops is a book that sets out to accomplish a certain task and accomplishes it brilliantly. This is not a beginner's book but, like an encyclopaedia, it is a delight to just thumb through the pages with a blank mind and allow a flood of pictures and stories about people, plants and places to grip you. You come back to Earth and find that your coffee has gone cold.
The very ambitious aim of the book is to enable you to take any snowdrop, be it species or hybrid, and put a name to it, or at the least to track it down to a narrow range of possibilities. To do this it demonstrates a degree of organization and precision that is regrettably usually lacking in gardening books. Moreover it does this without being dry or excessively academic in its writing style.
The book starts out with the structure of a snowdrop plant and an extensive account of the description, ecology and geography of the species by Aaron Davis. In 1999 Davis produced his own monograph of Galanthus defining 18 species and including a somewhat frustrating supplement on named cultivars. In the current account he has rewritten the descriptions and added a nineteenth species, Galanthus troyanus, named for ancient Troy in NW Turkey. Also included at this point are the naturally occurring hybrids - in other words not originating in gardens - of which there are only three.
Matt Bishop then takes over as the major writer on the cultivars - the book was largely his idea - with John Grimshaw acting as the general editor and contributing the chapter on Galanthophiles (snowdrop lovers). The meat of the book is then included in four chapters on species cultivars and three chapters on hybrids, two of these being brief introductory chapters.
To identify a particular plant the user is required to learn a limited vocabulary of terms mainly concerned with leaf type and the inner petals. Having mastered these, with the older gardeners among us substituting 'supervolute' for the older 'revolute' in the plants where the leaves are rolled in bud, then the keys to the sections may be used.
The keys, which are one of the most remarkable features of the book, are initial multiple-entry keys, as opposed to the dichotomous keys commonly found in plant identification manuals. To use them one has to look down a list of choices labelled with letters of the alphabet. For instance there are five choices in the chapter on hybrids with single flowers. Having chosen the appropriate one you then go through the dichotomous subdivision within it and are referred to the page where the plant or plants with these characteristics are described in detail. MY impression of the validity of these keys is that they seem to be very effective and represent a ground-breaking improvement in identification techniques applied to a gardening book. I contrast unfavourably same recent books - I'm thinking of Arisaema and Euphorbia in particular - where the lack of rigour and consistency of descriptions have left me frustrated and furious at being unable to identify the plants in my possession. I hope future authors take the hint.
Apart from the keys the book is an excellent reference for over 500 snowdrop cultivars including one or two named just before the book was published in late 2001. Many but not all of the cultivars have an excellent close-up photograph taken by Matt Bishop showing the flower characteristics. In addition there are same more decorative plates of clumps and gardens.
The book ends with chapters on cultivation, the Galanthophiles and conservation. In the extensive cultivation section the technique of twin-scaling is described in detail. This is now being used for the rapid propagation of particular clones enabling more people to own the newer cultivars. It is intermediate between tissue-culture and simple division of a clump of bulbs. Galanthophiles is a historic section giving brief biographies of the principal snowdrop growers.
This is a well-produced book generously illustrated with high-quality photographs. Since the authors were unable to find a mainstream publisher the printing cost was raised by subscription, accounting partly for the high price. But since there is no other single source for the information it contains, snowdrop growers and bulb growers in general will not only find it invaluable but a delight.