Friday Seeds & germination requirements for Viburnum species

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This fall I collected for the first time fruits of Viburnum acerifolium (maple-leaf Viburnum) and Viburnum rafinesquianum (downy arrow-wood Viburnum).

Surely, I was curious to see how the ‘seeds’ (endocarp + seed) are looking but how about their germination?
There are contradictory statements on the web; some say they first need a cold stratification, others say warm. It’s good to clarify this because I like to provide reliable info.

So, back to the books ;)

Viburnum acerifolium pits (endocarp+ seed)

Viburnum rafinesquianum pits

I like Baskin & Baskin: Seeds – Ecology, Biogeography, and Evolution of Dormancy and Germination (2014) because besides giving results from their own experiments, there are citations of hundreds of other articles on germination (of course, in some cases things are not always clear).

And, the warm stratification is the winner!
These Viburnum spp. have deep simple epicotyl morphophysiological dormancy and the germination requirements are: warm/moist stratification period (during which roots emerge), followed by a cold/moist period (after which the shoots grow).
In translation, if sown in late summer they will show up the next spring; otherwise they will germinate complete in the second spring after sowing.

On the same list are many other Viburnum species like: alnifolium, betulifolium, cassinoides, dentatum, dilatatum, lentago, opulus, parvifolium, prunifolium….Those who don’t have access to the book can read here a very short but conclusive summary regarding Viburnum acerifolium germination:
http://www.bioone.org/doi/full/10.1674/0003-0031%282005%29153%5B0232%3AEDIVAC%5D2.0.CO%3B2

Also another summary here:
https://www.researchgate.net/publication/267996605_Overview_of_seed_dormancy_in_Viburnum_Caprifoliaceae

Viburnum acerifolium

Viburnum rafinesquianum fall

Friday’s seeds – Mitchella repens

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I recently collected more partridge berries, together with Lindera benzoin and Prosartes lanuginosa (already shown, click on names).

Mitchella repens presents an interesting fruit, therefore worth a closer look. The red, fleshy, ‘two-eyed’ fruit it is formed after the fusion of the flowers ovaries – the white, fragrant flowers are disposed in pairs.  So, each pair of flowers will form one fruit. Each fruit has a spongy inside (a bit like Gaultheria) and will contain up to 8 seeds.

Mitchella repens fruits and seeds – Partridge berry, twinberry, squaw vine (Fam. Rubiaceae)

Why this perfect, evergreen ground hugging plant is seldom seen cultivated in the gardens remains a mystery to me. It can be easily propagated by cuttings as well.

Mitchella repens flowers

Mitchella repens fruits

Belated Friday’s seeds – Chamaedaphne calyculata

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Instead of writing about seeds, I was in collecting them ;) therefore a combined post about Chamaedaphne calyculata, the Leatherleaf or ground laurel.

The sole member of the genus Chamaedaphne (Ericaceae), leatherleaf is a low growing evergreen small shrub (up to 1.5 m tall). It is native to cool regions of the Northern Hemisphere, from North America, NE Europe to N. Japan, Mongolia and Siberia, where grows in all types of bogs, sedge fens, and open wetlands.
It is characteristic of mature and late stages of moss shrub communities, where it forms colonies, with rhizomes spreading in the sphagnum moss. It actually helps the installation of other species with whom is found growing, like Sarracenia, Drosera, Kalmia polifolia, Ledum groenlandica, various Vaccinium species.

The common name comes from the thick, leathery leaves, which are turning red-brown in the winter. It has a dense branching and the older stems turn gray with a fine exfoliating bark texture.
The white, bell shaped flowers on long inflorescences appear in April-July, depending on the region. Somewhat resembles Andromeda flowers, which is why Linnaeus first named it Andromeda calyculata.

Chamaedaphne calyculata, Leatherleaf

Fruits are capsules with split open and release the seeds shown below (wedged shaped, golden brown).

Chamaedaphne calyculata fruits and seeds

 It would make a great addition for small and large bog gardens. For those who have conditions and enjoy growing Ericaceous species – the seeds require cold/moist stratification and probably best to germinate them like in nature on a piece of sphagnum moss (in a pot/or ‘in situ’). I showed in a previous post how to easily germinate Gaultheria procumbens and Saxifraga cuneifolia in moss (Read here Sowing in moss).

Chamaedaphne calyculata seedlings germinated/growing on sphagnum moss (look around the Tamarack branch :)

 

 

Fridays Seeds – or is a fruit? part II Morina

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It’s Friday again so I continue the discussion (or better said monologue) about fruits versus seeds with Morina longifolia, commonly called Himalayan whorlflower.
If someone missed the Triosteum, see here.

What we call ‘seeds’ for Morina longifolia are also fruits (achenes). Morina is considered a warm germinator with the note that sometimes the hard teguments remain attached to the seedlings and are difficult to remove.

After being soaked in water for a few days, Morina achenes became soft and were easy to cut open. Actually, the tegument is quite thin compared to that of Triosteum, which is why I botched both seeds when trying to remove them (I couldn’t afford more fruits to test on).

But, we can have a look at the fully developed embryo I managed to extract from the second seed; notice the very large cotyledons.

Conclusion: soaking the seeds in water a few days (5-6), followed by sowing at room temperature should suffice for Morina. Before, I recommended keeping the seeds in a moist towel in the fridge for a couple of weeks, which is OK as well, but not really  necessary.
 

 

Friday’s seeds – or is it a fruit? Triosteum

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Sometimes we refer to ‘seeds’ without actually realizing that we are talking about the fruits.
This is the case of dry fruits like achenes, caryopses, samaras…, which tightly enclose the seed(s) and it would be practically impossible/or at least highly impractical to try to ‘extract’ the seeds.

So, why do we care if we sow seeds or fruits?
Knowing that we actually handle fruits, helps understanding why certain treatments are needed for the storage/germination process. Also, because in these cases we cannot see the actual seeds, we only make the assumption they are inside the fruit and will germinate in due time. Which perhaps they will, but sometimes there is no one there to do it!
To understand what I mean, you can have a look back at two notorious examples:
False assurance – Linnaea borealis
The Beauty and the Parthenocarpy – Acer triflorum

In the Caprifoliaceae family there are also species with dry fruits which we treat as seeds, like Morina and Triosteum. In both cases, they have hard teguments which play a role in retarding/obstructing the germination.

I wanted for a long time to have a closer look at Triosteum aurantiacum. I found no reliable info regarding its germination but someone who bought ‘seeds’ few years ago got back to me saying that by filing the fruits tegument, followed by GA3 and/or cold-moist stratification obtained good results.

So, I placed the fruits in warm water for a few days in an attempt to soften their teguments before I proceed to dissections. In Triosteum – and I refer here to Triosteum aurantiacum – the fruits resemble coffee beans, and only by looking at them one can imagine it will take a lot of time for them to disintegrate naturally in the soil.

Even after keeping them in water for few days I had to use a cutter to slice through them. The wall of the fruit is extremely thick and the seed is fused to it.
Here’s a plate showing the whole story in pictures:

I managed to extract one seed intact – inside, the embryo is invisible with the naked eye because of underdevelopment, pointing to the requirement of at least one period of cold/moist stratification.

This is a Triosteum aurantiacum SEED

Conclusion: these are the options to hurry up the germination for Triosteum – first, by filing the hard tegument with a metal file almost until reaching the seed, followed by cold/moist stratification 3 months.

Second, by nicking the end of the fruit (I used this myself for T. pinnatifidum), followed by cold/moist stratification for a few months. In this case, take care not to harm the seed when nicking the end and best to keep the fruits in water for a few days to somehow soften them.

A suplimentary GA3 treatment coupled with the cold/moist stratification may have some effect or not; I will try it this winter and we’ll know for sure.

About Morina next time…

 

 

 

Friday’s seed – Iris ruthenica

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Back to the Friday’s seed with an ad-hoc seeds photo session up in the mountains.
I. ruthenica has a relatively wide distribution from Eastern Europe to Asia, growing usually at subalpine and alpine elevations.
I particularly like it for the fragrant, deep blue/violet, flowers and the narrow leaves which form tufts of grassy ledges on the mountain slopes.

Iris ruthenica falls in the category of arillate irises and since the arils are drying fast, I wanted to capture them as fresh as possible, so not a very good image but it serve its purpose

Spending time on the mountain slope gazing at the blue sky and the rock walls would have been satisfying enough; weaving my hands through the grassy tufts to find the iris capsules made the moment unforgettable. The flowers pictures was taken during another trip, in a different location.

Friday’s Seed – Jeffersonia diphylla

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During a visit to the Aspen Groves Gardens to leave a few of my ‘precious’ seedlings for babysitting, I have also been ‘presented’ with nice, fresh and fat seeds of Jeffersonia diphylla :)

The seeds don’t keep very well in moist storage and I will be trying a new method this year, but you may never know how it goes…I recommend to those who have been waiting for it, to get hold of the seeds right now (orders are accepted until July 12th, then the Shop will be closed till August 10th).

All you need to know is here: https://botanicallyinclined.org/growing-jeffersonia-from-seeds/

Jeffersonia diphylla, Twinleaf; few seeds still attached to the fruit wall.

Jeffersonia diphylla seeds – 1 mm grid

 

And btw, those living in driving distance from Guelph, Ontario – this Saturday, July 8, Aspen Grove Gardens of Robert and Judy Pavlis are open for visiting from 10 am- 4 pm.  Don’t miss the opportunity!

Read more and see pictures here: http://www.robertpavlis.com/aspen-grove-gardens/

 

Note: Besides sowing fresh or moist kept seeds, I emphasize again the requirement for good germination.

Baskin & Baskin have shown that ripe seeds of Jeffersonia diphylla have an underdeveloped embryo. Seeds need high summer temperatures (30˚C) in order for the embryo to develop optimally and reach at least one mm in length before dormancy can be broken by cold stratification. If this requirement is not met, another warm/cold cycle is required by the seeds to germinate.

Jeffersonia diphylla two-year old plant

Friday’s Seeds – Tiger Iris

A few new Iris seeds from the rare side, so pictures are warranted. Despite its name, Iris tigridia (common name Tiger iris) is a completely harmless iris ;) hailing from the Altai region of Russia, Kazakhstan, Mongolia and China. Not an easy one, but extremely beautiful dwarf iris with blue streaked petals.

Images in wild habitat: Iris tigridia

Iris tigridia seeds

Iris potaninii, similar in habit (and distribution), has light to deep yellow flowers. As well from dry, rocky mountain slopes.

Images in wild habitat: Iris potaninii

Iris potaninii seeds

They both belong to the group of arillate Irises; I will update this post later with soaked seeds images to better observe the arils.

 

Friday’s Seeds – Papaveraceae

Back to seeds, and just a few here from the last published seed gallery.

Many of the species of Papaveraceae family present seeds with elaiosomes, a well-known adaptation to ant dispersal (myrmechory). In the general term ‘elaiosomes’ are included various seed appendages rich in lipids (with oleic acid as the main component), amino acids, carbohydrates and vitamins.

These appendages are often very beautiful and interesting. Problem is, you have to be fast in admiration because few days after dispersal/collecting (whichever comes first ;-) they will ‘shrink’ or simply ‘disappear’. This applies as well for the seeds which are kept in moist storage for later sowing/sales (keeping these species as dry seeds is strongly NOT recommended).

Stylophorum diphyllum, one of my favourites, with ‘mohawk-style’ elaiosomes (insert with seeds in moist storage).

Stylophorum diphyllum

Stylophorum lasiocarpum – with a different ‘hair’ style.

Stylophorum lasiocarpum

Corydalis solida – displays  ‘leaf shaped’ elaiosomes.

Corydalis solida

Dicentra cucullaria – a hard one to catch and the elaiosomes fade very fast.

Dicentra cucullaria

And, I cannot forget the Sanguinaria: ‘little snails’ trying to get away :)

Sanguinaria canadensis

 

More on the Papaveraceae seed gallery.

 

 

Friday’s Seeds – Fritillaria

And a Happy New Year!

I’ve recently sown few species new for me: Fritillaria and Gagea – Fam. Liliaceae.  I hoped that the close-up pictures will reveal minute differences between the seeds, and I will be able to use them for species identification. I was wrong – partially.

There are slight differences, especially when looking at them by comparison, but fair to say it is (almost) impossible to ID these Fritillaria spp. only after their seeds (F. ruthenica is a bit distinctive). Other Gagea species might be very similar with G. taurica as well. Not surprisingly, many Lilium species have also look-alike seeds.

In this case we can only trust and hope that after a few years the bulbs will flower to reveal the names written on the labels. With the same spirit of hope we look forward to the New Year, as a better, safer, and peaceful one for all !

Gagea taurica seeds

  Happy New Year!

                                    – and keep sowing :)                             

 

Friday’s Seeds – Pedicularis

Pedicularis is an interesting, large and varied genus of hemi-parasitic species – now part of Fam. Orobanchaceae.  Included are many attractive species, unfortunately not easy to germinate/cultivate – which makes them even more desirable! Too bad these beautiful plants have such a ‘lousy’ common name – louseworts!

The seeds are quite variable as well, although I can only show four species. I’ve added google plant images links (in red) for those curious.

Pedicularis atropurpurea

pedicularis-atropurpurea-seeds

Pedicularis atropurpurea seeds

 

Pedicularis sceptrum-carolinum, the Moor-king lousewort

pedicularis-sceptrum-carolinum-seeds

Pedicularis sceptrum-carolinum seeds

Pedicularis nordmanniana

pedicularis-nordmanniana-seeds

Pedicularis nordmanniana seeds

 

Pedicularis oederi

pedicularis-oederi

Pedicularis oederi

 

Their general common name: louseworts, allude to ancient beliefs that they would induce lice infestations in livestock.
I started some sowing experiments last year and I’m happy to continue.


 

Friday’s Seed – Lomatium nudicaule

 

Lomatium nudicaule – Indian celery, Indian consumption plant, Barestem biscuitroot
Fam. Apiaceae

lomatium-nudicaule

Lomatium nudicaule seeds (1 mm grid)

Lomatium nudicaule is a symbolic, valuable species for the Native People of British Columbia; the whole plant is edible and the seeds were chewed in case of colds, sore throats, tuberculosis.

From The Beliefs of the WSANEC People:
“That the KEXMIN, Indian consumption plant, is a good medicine used to clean and open the way for the pure spirits to come near”.