aceska at cue.bc.ca
Wed Jan 5 03:54:27 EST 1994
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No. 67 January 4, 1994
Address: aceska at cue.bc.ca Victoria, B.C.
Dr. A. Ceska, P.O.Box 8546, Victoria, B.C. Canada V8W 3S2
COMING EVENTS IN VICTORIA, B.C.
January 6, 1994 [Thursday] - Pacific Forestry Centre, Conference
Room, 10:30 a.m. till noon: "Pacific Yew and Taxol: A
Challenge for Sustainable Development" (A Seminar designed
to convey the broad range of research projects being
conducted on Pacific yew by scientists at the Pacific
January 18, 1994 [Tuesday] - Swan Lake Nature House, 7:30 p.m.:
"Botany Night - Succulents" - Identification of B.C.
families: Crassulaceae and Saxifragaceae.
January 19, 1994 [Wednesday] - Newcombe Auditorium, 8:30 till
noon: "Natural History Colloquium." (A presentation on
research projects conducted by the natural history
curators of the Royal B.C. Museum)
POSITION AVAILABLE - MYCOLOGY - OREGON STATE UNIVERSITY
From: TAXACOM at HARVARDA.HARVARD.EDU
Assistant Professor, Mycology. -- A tenure-track, 9-month
faculty position is available in mycology. Teaching respon-
sibilities include introductory and advanced courses in mycol-
ogy, and contributions to the general biology curriculum. The
successful candidate is expected to develop an extramurally-
funded research program. Areas of research include, but are not
limited to, evolutionary biology, population genetics and sys-
tematics of fungi. The individual chosen will be responsible for
the oversight of the mycological collection which is housed in
the Oregon State University Herbarium within the Department of
Botany and Plant Pathology.
Application closing date: February 28, 1994
Position available: September 16, 1994
For more information contact:
Chairperson, Mycology Search Committee
Department of Botany and Plant Pathology
Oregon State University
Cordley Hall 2082
Corvallis, OR 97331-2902
Telephone: 503-737-5286 FAX: 503-737-3573
FOREST SUCCESSION AFTER 1480 ERUPTION OF MT. ST. HELENS
Ring counts on Douglas-fir (Pseudotsuga menziesii) stumps were
used to reconstruct the early development of old-growth forests
northeast of Mount St Helens, Washington, after catastrophic
forest disturbance by tephra fall from an eruption in 1480. In
addition to documenting volcanic and other disturbances in
forests near the volcano, this investigation tests the
hypotheses that distant seed sources, repeated disturbances, or
competition from shrubs and hardwoods caused Douglas-fir to
slowly (>90 years) recolonize sites in the western Cascade Range
400 to 500 years ago. Findings show that long distances from
seed sources could have contributed to the slow development of
regional old-growth Douglas-fir stands after catastrophic dis-
turbances, but not repeated disturbances during stand develop-
ment, and not competition from shrubs and hardwoods. The find-
ings also suggest an AD 2020-2160 timeline for natural refores-
tation of the Mount St Helens National Volcanic Monument.
[Abstract from: Yamaguchi, D.K. 1993. Forest history, Mount St
Helens. Research & Exploration - A Scholarly Publication of the
National Geographic Society, 9(No. 3 - Summer 1993): 294-325.]
REPORTS ON POISONING BY GIANT HOGWEED, HERACLEUM MANTEGAZZIANUM
Andrews, A.H., Giles, C.J., Thomsett, L.R. 1985. Suspected
poisoning of a goat by giant hogweed. Vet-Rec. 116(8): 205-7.
A five-year-old male African pygmy goat became ill four weeks
after transfer from a zoological garden to a municipal park. The
animal was subdued, refused to eat and drink and showed profuse
salivation. Examination of the mouth revealed severe ulceration.
The condition gradually responded to nursing and supportive
therapy. Circumstantial evidence suggested the possibility that
the lesions were caused by giant hogweed (Heracleum
mantegazzianum). Supportive evidence that the plant could
produce lesions was provided by the application of a cut stem to
the hard palate and a solution of various dilutions to clipped
areas of the backs of two ewes. Both ewes produced reddened skin
when the concentrated solution was applied and both showed
marked reddening of the gingival mucosae and in one animal small
ulcers developed in the rostral part of the mouth. It is sug-
gested that H. mantegazzianum may be a potential hazard for
Pira, E., Romano, C., Sulotto, F., Pavan, I., Monaco, E. 1989.
Heracleum mantegazzianum growth phases and furocoumarin content.
Contact-Dermatitis 21(5): 300-3.
The observation of photocontact dermatitis from Heracleum man-
tegazzianum Sommier et Levier in 2 gardeners at work prompted
the analysis of furocoumarin content of stem, leaves and fruits
of the plant during a period of 1 year. Their concentration was
found to be maximal in fruit, intermediate in leaf, and minimal
in stem. Psoralen was the most prevalent substance in the leaf
and bergapten in the fruit. In the stem, in contrast, individual
furocoumarins were found in lower but variable concentrations. 3
furocoumarin seasonal peaks were observed in the leaf: the
maximal peak occurred in June, the intermediate in August, the
minimal in November. This trend corresponds to 3 biological
phases of the weed.
Ippen, H. 1984. [Photodermatitis bullosa generalisata] Derm-
Beruf-Umwelt. 1984; 32(4): 134-7. [German]
Two observed cases indicate atypical forms of phyto-
photodermatitis. Unusual localisations or generalized outbreaks
have to be taken into account in cases of sunbathing without
clothes on. Power lawn mowers with rotating blades spread
Heracleum and other phototoxic juices via freshly cut grass,
causing diffuse - as opposed to striped - manifestations on the
uncovered skin areas. The most certain prevention of such a
reaction is to known which few plants are responsible for phyto-
photodermatitis and to avoid them in sunny weather. The plants
should by no means be exterminated, even those (such as
Heracleum mantegazzianum, "giant hogweed") which have a tendency
Prinz, V.L., Kostler, H. 1976. Ein Bericht uber 3 Falle von
toxischer Phytophotodermatitis durch Heracleum mantegazzianum
(Riesenherkulesstaude). Dermatol-Monatsschr. 162(11): 881-6.
Camm, E., Buck, H.W., Mitchell, J.C. 1976. Phytophotodermatitis
from Heracleum mantegazzianum. Contact-Dermatitis. 2(2): 68-72.
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