Slatsz' plant photo-biography: Dodecatheon pulchellum, dark throated shooting star

9/9/2014 6:39 AM

9/15/2014 1:03 PM

Dodecatheon pulchellum, dark throated shooting star

Burke has it in most counties east of the Cascades and several counties west of the Cascades. USDA has them in all western states, the Dakotas and Nebraska and, it seems, western Canada and Alaska to the arctic.

It is native

It is perennial

Dodecatheon genus - shooting stars

Perennial from a rhizome or caudex [a swelling of the stem at ground level that persists from year to year] but they don’t form ‘cushions’ or ‘mats’. The roots are fibrous. Some species have bulblets. Burke says there are 8 Dodecatheon species in Washington State, 2 species reported in Spokane County, D. pulchellum and D. conjungens. I suppose those in Drumheller Springs park are D. pulchellum. Photos from Riverside State Park may be D. conjungens.

Dodecatheon

Linnaeus named the genus 1753. He simply took Pliny’s not very helpful name for the primrose. The primrose was supposedly protected by the gods. Greek: dodeka – 12, theoi – gods, so, Dodecatheon, twelve Gods.

Pulchellum

The biologists like the term and attach it to numerous animals and plants. It’s from the Latin, pulchellus, beautiful little. So, twelve beautiful little Gods.

Another Greek-Latin combination name of the sort linguistic purists complain about. And which some of us don’t find helpful.

Flora of North America: “… the variation within the more widespread species (such as …the western D. pulchellum) can be bewildering.

Slichter: “The tube at the base of the petals is white or yellow-ringed with a thin, wavy reddish-purple ring at the very base.”

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It may be that I have photos of two species, here. As I said, above, Burke has two species recorded in Spokane County. The main color of the petals [that are not white] varies to some extent. The shape of the apex of the leaves varies. Some leaves are rather pointed, some are smooth ovals.

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The leaves in the photo below look somewhat pointed. Are the petals merely faded with age? This photo was taken in Riverside State Park, the 1991 burn. The curved pedicle suggests the flower is fairly new. The open stamen may suggest it’s somewhat older.

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Flora of North America says the inflorescence is an umbel. Three dictionaries have three slightly different definitions of an umbel. They agree that the pedicels [short stems with flowers off the main flower stalk] rise from about the same point. That much of the definition fits well enough. The umbel of D. pulchellum with large flowers and few flowers doesn’t look much like the umbels of yarrow, biscuitroot, yampah or onion.

The pedicels seem to rise straight up from the flower stalk with the birth of a bud, bend down [the flower becomes pendant] as a bud opens into a flower then rise up again and grow longer as the flower fades and the ovary becomes a fruit.

In the photo below the lateral structures seem to be buds lowering with undeveloped petals and stamen that are not well exposed but the petals of the structure on the left look withered.

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Notice the short pedicles, flower stems, curved down on the flowers with full set of petals and the long, erect pedicles on those with their petals fallen away.

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I don’t understand what I read about the filament tube and the anthers of D. pulchellum.

I will need to dissect flowers next year. This is my attempt to make sense of the flower just looking at the accumulated photos.

Corolla is the term for the petals as a group. The corolla of D. pulchellum is fused into a short tube at the base. The lobes of petals are reflexed, that is, bent back toward the pedicle.

I call the ovary ‘inferior’ because it is out of sight, below the other flower parts. The corolla tube will be attached to the top of the ovary. The red circles on the base of the corolla tube seem like they should be significant but I have no idea what their significance might be.

The sources seem to be saying that the yellow structures with the purple tips are filaments. They are not at all like any filaments I have seen to this time. Filaments I have seen are a slender, rather thread like column holding up the pod of an anther. [Oops. How about the filaments of disk flowers on Asteraceae?]

The whitish structures extending beyond the purple tips of the filaments are said to be anthers. The anthers are said to be poricidal. The pollen gets out through pores.

The flower in the photo below is probably D. conjugens, not D. pulchellum, but it is the best image I have of texture of the yellow ‘tube’ that seems to be what authorities speak of when they talk about the filaments.

I don’t know where to look to see the ‘connectives’.

The dictionary of botany says connectives connect the pollen sacs in the anthers:

http://botanydictionary.org/connective.html

Paul Sclichter

“The filaments are united to form a tube of yellow or purple anthers projecting to 1 cm from the mouth of the corolla tube. The anther connectives are smooth …”

From Flora of North America

“Filament tubes usually yellow, if purplish, then connectives smooth or longitudinally wrinkled at anthesis …” [Anthesis – flowering.]

The transparent style and stigma sticking out of the anther tube, too, are unusual in my experience. The style is more than one style, fused but the stigma of the individual styles do not flare. The stigma is capitate, it is a head-like enlargement on the tip of the style.

It may be that the flower on the left is D. conjugens and the flower on the right is D. pulchellum.

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I Googled ‘poricidal’ for spelling. I do have it correct but the speller doesn’t recognize it. And there, for some reason, is an article on ‘buzz pollination’ … I can’t believe it. I thought the writer that used the term in a source somewhere else was being cute. Oh, well. [There is the more botanical sounding word for it, ‘sonication’.]

There’s the connection, ‘Poricidal anthers of various flowers are associated with buzz pollination by insects.’

This seems to be from the University of Nevada, Reno. They say their school is a great place to study bee behavior.

Their website has several videos of bees trying to do their thing, one video goes on for 10 minutes of bee frustration. One of the videos shows porocidal pollination via tuning fork.

http://www.anneleonard.com/buzz-pollination

Six to eight percent of plants require buzz pollination. Most do not provide nectar. The pollen is a sufficient reward. The bees need the protein provided by pollen, especially for bee babies.

In most plants the pollen is readily available from open anthers. But the six to eight percent of plants that require buzz pollination have long anthers that don’t open, the pollen comes out of a pore. The bee has to learn to create vibrations to force the pollen out of the anther. Sometimes it takes the bee awhile to figure it out.

JSTOR

JSTOR is part of ITHAKA, a not-for-profit organization helping the academic community use digital technologies to preserve the scholarly record and to advance research and teaching in sustainable ways.

http://www.jstor.org/discover/10.2307/2390076?uid=3739256&uid=2&uid=4&sid=21104627138127

The university of Calgary says Dodecatheon have ‘Introrsely dehiscing porocidal anthers’ Introrsely dehiscing anthers release pollen toward the center of the flower.

These guys say that animal pollination has diminishing returns. I suppose that’s because the animals eat the pollen or, perhaps, just lose it in their travels. They think it’s better for the flower to limit the pollen take of the individual pollinator and increase the number of pollinators that visit the flower. The way Dodecatheon conjugens manages this is, its anthers are ‘tuned’ to higher vibrations than the bees can generate, so they are inefficient. They leave pollen for the next guy.

Foliage appears early enough to be caught by a late frost.

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Buds nestled in basal leaves

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Buds rising from basal leaves

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Buds at the top of their scape. The more developed bud is lowering into pendant position.

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A bud opening, the stamen beginning to extend.

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A white bud opening

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Petals of the corolla beginning to reflex or not? Are they coming or going? The long white strap below the flower seems anomalous.

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None of the sources I’ve looked over declare whether the ovary of D. pulchelum is superior, inferior or other. It seems that it must be inferior because it’s out of sight below the corolla cone. It only comes into view when the petals wither. An inferior ovary is below the attachment of petals, sepals and stamens.

The attachments of the flower parts are only visible in these photos after the petals have withered.

In the photo below, the flower on the left shows the calyx and its sepals rising from the receptacle, the thickened bit at the top of the flower stalk, not from an hypanthium. The withered corolla of petals, however, seems to be pulled away from what might be an hypanthium. I suppose it could be the ovary itself, except that ring of stamens encircling the style and stigma would seem to rise from the ovary.

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[see a miscellaneous gallery of photos below the following speculation]

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One more go-round with ‘inferior ovary’.

The ovary is the base of the carpel, the fundamental female reproductive organ. It encloses the ovum, the egg or eggs that will become a seed or seeds. The style and stigma are areas of the carpel above the ovary. They wither after the egg is fertilized.

The ovary sits on the receptacle, an enlargement at the top of the flower stalk.

Botany Word of the Day; An illustrated guide to Botany terms.

http://plant-phytography.blogspot.com/2012/10/hypanthium-cup-shaped-or-tubular.html

Hypanthium – A cup shaped or tubular expansion of the receptacle of a flower.

I haven’t seen another discussion of the hypanthium that relates it to the receptacle.

It seems to me that, in the case of the inferior ovary, the ovary is embedded in the receptacle. So the hypanthium is really only a receptacle that is not flat as in Asteraceae, but cup shaped, surrounding the ovary.

Botanists like to distinguish between superior ovaries that sit on top of the receptacle with the other floral parts rising from the receptacle surrounding the ovary and inferior ovaries, as I suggested, embedded in the receptacle with the other flower parts rising from the rim of the receptacle [the hypanthium] enclosing the ovary.

Reality enters and brings confusion with it. The other flower parts may arise from the middle of the hypanthium, above or below the middle of the hypanthium.

And the confusion seems to be compounded in D. pulchellum with the calyx rising from the receptacle, enclosing the ovary and the petals and stamen apparently rising from the ovary.

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A miscellaneous gallery of photos:

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