BEN #67

[Adolf Ceska]

BBBBB    EEEEEE   NN   N             ISSN 1188-603X
BB   B   EE       NNN  N
BBBBB    EEEEE    NN N N             BOTANICAL
BB   B   EE       NN  NN             ELECTRONIC
BBBBB    EEEEEE   NN   N             NEWS

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
      Forestry Centre)

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
From: Medline

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
grazing ruminants.

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
to spread.

Further references:
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.

                        HAPPY NEW YEAR !
                  VSE NEJLEPSI V NOVEM ROCE !