Viburnum opulus, highbush cranberry tree; Adoxaceae family

10/19/2014 7:57 PM

10/25/2014 10:47 AM

Viburnum opulus, highbush cranberry tree; Adoxaceae family

I only noticed this shrub when it was in fruit, July 28, 2011. It was ‘tucked away’ on the north side of tall pine grove. I looked for it in 2012 and the people who … well … never mind. Some one cut it down and burned the area.

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The plant has come back but had not blossomed when I looked, last.

June 15, 2012

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July 24, 2012

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I have very few photos and the photos I have were lost until just now. There are two Viburnum in the park, one is introduced and one may or may not be native. I’ll assume it is native, for now. The photo folder of the assumed native, V. opulus, had found its way into the folder with the introduced Viburnum … the familiar snowball shrub.

I photographed one last sterile blossom June 24, 2011. Burke says, V. opulus blooms May to July. This one must have bloomed in mid-June.

Notice that there is no place at the center of the petals for reproductive organs. That was a great mystery at the time.

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The inflorescence is a compound umbel. Rays branch from the receptacle at the top of the flower stalk then branch again before the branches support flowers. Actually it looks like they branch three times. I need a better photo.

Compound umbels sometimes have flowers that are different in some way on the outside ring of the inflorescence. V. opulus has a ring of sterile flowers that are very large relative to the flowers within the inflorescence.

I have not found a photograph of V. opulus in full bloom among my favorite internet resources. There are some elsewhere on the internet but the resolution is so poor they are not helpful, they don’t really show interior flowers.

Paul Slichter has an excellent photograph of the sterile ring flowers but the interior flowers are still in bud:

http://science.halleyhosting.com/nature/plants/5petal/honey/viburnum/opulus.html

Burke has one photo in their collection showing a few interior flowers in bloom.

http://biology.burke.washington.edu/herbarium/imagecollection.php

Click on ‘plant scientific names’

Click on ‘V’

Scroll down to Viburnum opulus

Click on it

Scroll down to the photos at the bottom of the page

Click on the third image in the top row to enlarge it, the photo showing a large sterile flower.

Click on the image again to enlarge it further.

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It seems from the photos I’ve found that the sterile outer flowers come on first and fade last.

The photos below give an idea of what the inflorescence was.

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I was a little bit quick.

Gerald Carr’s photos do not have the inflorescence in full bloom but do have photos showing some interior flowers.

The Carr brothers’ sites also enlarge their photos, at least on a part time basis.

Click on the photo once to enlarge it. Then a magnifying glass cursor with a plus sign appears. Click again and get one more enlargement.

Gerald Carr

This address takes you directly to the photo. This is the first level of enlargement. Note the magnifying glass icon. Click for closeup.

http://www.botany.hawaii.edu/faculty/carr/ofp/images2/vib_opu_rlc_XI__2994b.jpg

This address to see the rest of his V. opulus photos:

http://www.botany.hawaii.edu/faculty/carr/ofp/vib_opu.htm

Gerald Carr says the plant is exotic, apparently meaning that it is introduced. Burke says it’s native and widespread in Washington State.

Robert Carr says it’s native.

Damn. We are talking about 2 varieties of V. opulus. Gerald Carr AND Burke say Viburnum opulus var. opulus is introduced. Robert Carr AND Burke say Viburnum opulus var. Americanum is native.

Burke shows var. Americanum only in Pend Oreille County. Let’s hope it is merely not reported in Spokane County.

Robert Carr’s photos of V. opulus are all dated Yakima County.

http://web.ewu.edu/ewflora/Adoxaceae/Viburnum%20opulus.html

The burke photo, apparently from Pend Oreille Counts shows interior flowers with pink anthers. Robert Carr’s photos show interior flowers with white anthers.

My photos have information about the leaves. They are rather maple leaf shape with three lobes, often somewhat pointed

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often not so much

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There’s a lot of variety in the leaf shapes on the same branch

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Burke and E-FLORA BC both mention hairs on the veins on the back of the leaf.

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Reminder

Different stems have different names. The flower-stalk is the peduncle, a stem between the flower-stalk and the flower is a pedicel, the stem of a leaf is a … damn … have to look it up. Google has to look it up. Petiole. I’m sure other stems and branches have Latin and Greek names but that’s enough for now.

The petiole on this leaf is deeply channeled.

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I can’t remember the name for these little buggers, either, not at the moment [glands]. But Burke says they are at the ‘summit’ of the petiole … and elsewhere on the plant. E-FLORA BC says the glands are ‘upward’ on the petiole.

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The resolution isn’t good but you can sort of see some glands on a branch.

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Burke says the petioles of V. opulus leaves have linear stipules 2-6 mm. long. The stringy bits must be them.

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The fruit of V. opulus is a drupe. At least one definition says a drupe usually forms from a superior ovary. Burke says V. opulus has an inferior ovary. Oh, well.

We buy drupes in the store: cherry, plum, peach, apricot and olive. But walnut, almond and coconut as well.

A drupe has a thin skin and a thick, fleshy coat surrounding a hard ‘stone’ with the seed inside. So where’s the fleshy coat on the walnut and almond, you ask. Their fleshy coat was removed before they got to the store.

So we eat the flesh of some pomes and the seeds of other pomes. I can’t explain the coconut. I don’t remember seeing seeds inside the white ‘rind’.

Missouri Botanical Garden says the drupes of V. opulus are edible fresh right off the bush.

The Wikipedia article says of V. opulus, “The fruit is edible in small quantities, with a very acidic taste; it can be used to make jelly. It is however very mildly toxic, and may cause vomiting or diarrhea if eaten in large amounts.^[6]”

It is not certain that they are talking about the same variety or even the same species.

We see the glands on the stems in these photos, not very well. Burke says the glands are stalked. I’d like to know about the function of the glands.

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The forest fire people are very interested in the regeneration of plants.

Fire Effects Information Database (USDA)

http://www.feis-crs.org/beta/

Viburnum opulus

http://www.fs.fed.us/database/feis/plants/shrub/vibedu/all.html

click on ‘Botanical and Ecological Characteristics’

V. opulus is rhizomatous [22].

REGENERATION PROCESSES : 

Sexual reproduction:  Highbush cranberry begins to produce fruits at approximately 5 years of age, and then produces large quantities nearly every year thereafter.  

Vegetative reproduction:  Highbush cranberry can reproduce vegetatively by natural layering [limbs touching the ground] and sprouting from damaged root stocks, stem bases, and stumps.  The plant is rhizomatous, but there is no evidence of lateral spread from the parent by rhizome or root suckers.

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The seed reproduction is interesting. 

“The one-seeded fruits are dispersed by the birds and mammals that consume them [6,22].  Germination is normally delayed until the second growing season after ripening.  The seeds exhibit seed coat and embryo dormancy that requires a two-stage stratification [stratification: processing by horticulturists. Natural stratification is cold winter followed by spring moisture. V. opulus needs two sessions.] to be broken.  Most successful germination takes place when a warm period is followed by cold stratification [21,22,59].  The radicle [embryonic root] emerges and begins growth during the warm period, and the cold period breaks the dormancy of the plumule [the shoot [above- ground stem] emerges from the plumule], which then grows when temperatures become warmer.  The time period of these stages is critical but has not been worked out in detail.  Clean, air-dried seeds can be stored up to 10 years without losing viability.  Highbush cranberry is a seed-banking

species. [I believe this means that their seeds can germinate when conditions are right after many years in the soil.]

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Putting things in categories and naming the categories is essential to the work of scientists. If they do a good job of naming things and processes the names are helpful in thinking about them. [Do I have to sneer and say the botanists’ names for things are very often not at all helpful?]

The Seed Bank.

If I understand correctly, a seed bank is nothing but soil with seeds in it. I think ‘seed bank’ is a less than perfect job of naming but I don’t have a better name. I suppose the analogy with a commercial bank is suggestive.

Here are some plain, strait-forward names that do their job. This is from the fire fighters’ website.

Seeds in the seed bank

The seeds of transient species are viable only to the next opportunity to germinate.

The seeds of persistent species are viable, in some cases, longer than a year.

The seeds of short term persistent species germinate or die within 5 years.

The seeds of long term persistent species are viable in the soil longer than 5 years.

Chenopodium album, lamb’s quarters, [A very familiar ‘weed’ in Spokane … an edible weed, by the way.] is commonly viable for 40 years. It may be viable up to 1600 years. So say the fire fighters.

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More by the fire fighters

FIRE ECOLOGY OR ADAPTATIONS : 

Highbush cranberry sprouts from the stump, roots, or underground stems

following fire [13,61].  Sprouting may also occur at the base of

fire-killed aboveground stems [22,24].  Highbush cranberry roots are

buried approximately 8 inches (20 cm) below the soil surface, allowing

them to survive light fires that do not entirely remove the organic

layer [51].  Rhizomes will also survive fires of this nature.  Highbush

cranberry seeds are hard and have thick seed coats, making them somewhat

resistant to fire [59].  Regeneration by seeds stored in the soil may

actually be favored by low-severity fires [22].