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Hi Randy & All, July 25, 2008
Unless collected for special purposes, the Herbarium specimen is I
think intended to be an unambiguous testament that a certain species was
present at the place and date specified.
So the primary objective is normally to assemble the selection of
parts or developmental stages that will enable, if possible, unambiguous
identification while not encumbering the Herbarium sheet with a brush
pile or haystack. Typically this would include some of the root system
if feasible (or necessary), basal leaves if present, stems folded or
segmented (if necessary), and depending on the plant one or more of
unopened flower buds or equivalent, fully open flowers, immature fruit
and mature fruit. For something e.g. like White Pine and any small
leaf-bearing twig would be fine and for Eleocharis because they are
usually small, a portion of an entire clump, including roots, would
normally be collected but only if fully developed seed were present.
I don't want to take time to check this but my gut feeling based on
55 year-old memories; for something like Heracleum one would want mature
or nearly mature fruit, some flowers (both as umbels or umbel rays), a
leaf or halved leaf, & a stem segment including the leaf sheath.
The point at which umbel rays are attached is not the receptacle and
no doubt it has a name but I don't recall it.
Yt, DW
Randy Lauff wrote:
>
>
> 2008/7/24 David & Alison Webster < dwebster@glinx.com
> <mailto:dwebster@glinx.com> >:
>
> Hi Randy & All, July 24, 2008
> I notice that umbel size is not mentioned in Gray's 7th ed., 8th
> ed. or in Munz & Keck California Flora which would suggest wide
> variation to the point of not being diagnostic. In general,
> excessive fertilizer will promote vegetative growth to the
> detriment of flowering & fruiting.
>
> Interesting point. The leaves were also huge, so big that I had to
> choose a small one to mount on a standard herbarium sheet (about 42 x
> 27 cm). Perhaps the largess of the leaves allowed for more food
> production to generate the large flower?
>
>
>
> Both our herbarium curator and botanist are away at the moment, so I
> had to use my imagination to mount the umbel...I cut about a 5 mm
> slice through the receptacle (can that word be used here - where all
> the umblelets (?!) attach) and got a fan-shaped segment which barely
> fit onto another herbarium sheet.
>
>
>
> Would any of you who know more about mounting big plants have done
> something differently?
>
>
>
> Randy
> _________________________________
> RF Lauff
> Way in the boonies of
> Antigonish County, NS.
>
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