Friday Seeds & germination requirements for Viburnum species

,

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

Here they go!

,

Trillium grandiflorum seeds are just beginning to germinate! As well is Paris quadrifolia; I noticed the first signs last Saturday (with my x40 lens).

I snapped a few pictures when I was packing some today; they are advanced enough to be noticeable even if the pictures are not great.

Trillium grandiflorum seeds starting to germinate

 

Paris quadrifolia seeds barely showing the radicle

No matter what someone else says or writes, this is happening every year.

For these species, moist stored seeds kept at warm (room temperature) will always start to germinate around this time (roots only).
From all T. grandiflorum seeds, 70-80% will germinate now (roots) and then show the first leaves in the spring after a period of cold stratification. The rest will need one more warm/cold cycle to go through the same cycle.

Paris quadrifolia seeds were also tested two years ago and at that time they all germinated by November (this year I only got few and were promised to someone).

On short, hurry up if you think about Trillium grandiflorum; right now I can select and send seeds that are just about to germinate (they are enlarged and lighter in colour – see the feature image).

 

 

Fridays Seeds – or is a fruit? part II Morina

,

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.
 

 

To autumn – the lusty song of fruits and flowers

, ,

Images from out in the woods, from the garden and even along the margins of the roads, all reflecting the harmony of colours, shapes and textures that autumn brings, were flashing through my mind when cleaning fruits today.  Such an easy way to go into a lyrical mood…(I’ll keep it short ;)

“O Autumn, laden with fruit, and stained
With the blood of the grape, pass not, but sit
Beneath my shady roof…
………………………………………
Sing now the lusty song of fruits and flowers”.

                                           W. Blake – To Autumn

Euonymus obovatus and Arisaema

Arisaema flavum

Solidago canadensis -Rhus

Scabiosa caucasica

Colchicum

Cornus sericea

Cimicifuga racemosa

Polygonatum pubescens

Rosa

 

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

, ,

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…

 

 

 

Moist packing – what’s that?

, ,

As I was packing seeds today, I thought that maybe some people who never bought or they buy for the first time moist packed seeds may wonder what they would get.

Sometimes I get questions as well, so although I have shown pictures in previous posts, it is good to tell again. There is no secret; seeds that are known to be hydrophilic (to make a long story short – these are seeds which need to be sown right away after collecting or if not, kept moist to preserve their viability), are cleaned from the fruits and stored in slightly moist vermiculite in Ziploc bags. And no, there is no need to spray the seeds with anything chemical.

For shipping, the portion of seeds is placed in smaller bags with a bit of the moist vermiculite (*exception for some AU and NZ orders, when the seeds may be packed with a piece of moist paper towel). These seeds are to be sown right away after receiving.

Asarum canadense moist packed seeds for shipping

These small bags are not intended for storing the seeds long term!!! (I know someone tried to do that, that’s why I mention it). If you really want to keep the seeds longer, and /or provide stratification in the fridge instead of sowing, you need to transfer them in larger bags with added moist vermiculite (slightly moist peat works as well).

Very small seeds, like those of Coptis shown in the picture, are easily sown by spreading the content of the bag on top of the potting mix (no need to pick the seeds from the vermiculite). Even larger seeds are better sown this way.

Coptis trifolia moist packed seeds

In case of hydrophilic seeds, if kept dry they will either not germinate at all, or will germinate poorly/over a longer period of time. Keeping them moist and allowed the required cycles that mimic the natural conditions will result most times, in 100% germination in the spring. It is a lot of extra work but worth doing it.

Thank you! – Merci! to all our customers

 

Overheating – Roscoea tibetica f. atropurpurea

,

In this part of the world, the heat & humidity combined together can be quite unbearable. Today, we reached around 38C, with the humidex!
Even the little Roscoea tibetica f. atropurpurea couldn’t take it anymore and the first capsule bursted out in desperation. Two more to follow…

Roscoea tibetica f. atropurpurea with split capsule

I talked about this Roscoea a few times; a cute little thing and a curiosity. It shows up very late (June), produces only few flowers and it is so small that it needs a special place to be seen. Plus, the capsules split in a most unattractive way. Still, I found it charming :) Don’t you?

Roscoea tibetica f. atropurpurea – measured last year

Friday’s seed – Iris ruthenica

, ,

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

, ,

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

The Goldthread

One little species I’ve just managed to collect seeds from, although not an easy task, is the Goldthread – Coptis trifolia.

A member of Ranunculaceae with circumboreal distribution, Coptis enjoys cooler, moist conditions in deciduous or coniferous forests and often grows on mossy bumps on the wetland edges together with other species like Medeola, Clintonia, Viola macloskeyi, Trientalis borealis, Skunk cabbage…

Coptis trifolia, Goldthread; the name goldthread comes from the golden-yellow, thin rhizomes that were chewed by Native Americans to treat mouth sores, and later used as ingredients in gargles for sore throats and eye washes.

Almost every year I have the privilege to admire the white, rich in nectar flowers early in the spring, at the same time when Hepatica is in flower (in SW Ontario). It will put up new shiny, evergreen trifoliate leaves after is done flowering and setting seeds.

About the seeds, well, being a Fam. Ranunculaceae member I found some sources saying it requires moist storage to preserve viability.
I was reluctant given the small seeds to keep it that way, plus that I never had too many seeds anyway. Going deeper into the subject, it seems that the tiny seeds contain an even tinier underdeveloped embryo.

Coptis trifolia capsules and seeds (1 mm grid)

Like other Ranunculaceae with similar seed collection times and underdeveloped embryos, for best germination I recommend a slightly warm/moist stratification period (meaning sowing in early fall asap) followed by a cold/moist stratification (winter) (it is possible to require a second warm/cold cycle and germination to occur in the second year after sowing).

Note:
Coptis trifolia was first described as Helleborus trifolius by Linnaeus in 1753.  

Refreshing – Aconitum ‘Ivorine’

,

White on blue is a refreshing combo. Yesterday, amidst the heat wave I took few pictures of Aconitum ‘Ivorine’ just starting flowering.
Pure white, tinged with green flowers on sturdy stems make this Aconitum very appealing.  The bluish background provided by Juniperus ‘Wichita’ is pure serendipity – most of my plants were planted where I could find a proper space in this new garden without much thinking of colour combinations.

Aconitum septentrionale ‘Ivorine’

It doesn’t clump excessively, which is unfortunate; I could use more seeds, so this is the next ‘ivory’ generation! Very easy to germinate if the seeds are sown fresh or kept moist and allowed a warm/cold cycle. The pots can be brought indoors around February to germinate and grown under lights will achieve a better growth by June. I had no more space available this year so they germinated outside somewhere beginning of May.

Aconitum septentrionale ‘Ivorine’ freshly transplanted seedlings

 

 

 

Exception – Sedum atratum

,

Growing annual plants is very satisfying – they germinate, grow, flower and set seeds in one season; some will also self-seed themselves for the next year; nothing to worry about throughout the winter…I can understand the attraction. But I still like to grow perennials ;))

Sometimes I make exceptions – and Sedum atratum is one notable because I collected the seeds from a place in the Carpathians that is not easy to reach; it reminds me about ‘my mountain’, and belongs to the ‘little plants’ category.

Sedum atratum ssp. atratum in the Carpathian Mts.

Last year some nocturnal animal took a snack from a little clump growing at the edge of the rockery; luckily a few seeds were already into the safety of the tufa rocks and I can continue to enjoy it. Maybe even collect a few seeds later.

Sedum atratum ssp. atratum among Dryas octopetala ‘Tundra Pygmy’

Sedum atratum ssp. atratum is an annual species, with the mention that I’ve seen non-flowering rosettes and most likely also behaves as a biennial; from the mountains of South and Central Europe.
It is great in a rockery or scree area, showing here in there, without bothering other species; small, fleshy stems and leaves, which turn deep red later in the season.
Best to scatter the seeds in the desired place, in late fall or early spring.

 

A late arrival – Lindera benzoin seedlings

I’ve been watching out for Lindera germination on a regular base and had started to think about what could have been wrong: I collected the seeds myself, cleaned the pulp by hand (the seed coat is very thin), kept them moist and warm in late fall and then provided winter cold outside.

Lindera benzoin fruits & seeds

It seems nothing was wrong – a couple of days ago they finally showed up! Apparently they like to germinate (speaking of the shoots) after it gets a little warmer.

Welcome!

Lindera benzoin seedlings

Breaking the tradition – Medeola virginiana germination

,

More updates on germination requirements

It seems that Medeola virginiana seeds don’t follow the traditional double morphophysiological dormancy (MPD). Unlike most species with this type of dormancy, which require a cold-warm-cold cycle to germinate and produce roots in the warm period (2 years seeds), M. virginiana seeds do not form a root during this time; instead, root and cotyledon emerge at the same time in the second spring after sowing.

Medeola virginiana seedlings; seeds sown fall 2015 – germination spring 2017

Speculations are that this sort of germination pattern may represent a transition towards a type of more complex MPD.
Or is it sorcery involved ? ;-)

OK, the practical meaning of all this: be patient and don’t scratch the pots looking for tiny roots in the first year.

For me: I could keep the seeds in moist storage until the second spring, if I would have that many…

Note: again, we are talking here about sown fresh/moist kept seeds.

Back to basics – Aquilegia

,

Most probably the first plant I grew successfully from seeds (that is, which I saw it flowering :) was an Aquilegia. I don’t remember precisely which one and it doesn’t matter; I like them all very much. They are easy to grow, provide a whole array of heights/colours and are good pollinator plants.

Yes, some are short lived, and yes, most will be attacked by leafminer, and of course, they hybridize and not all seedlings come true to the mother plant, but I still like them very much.

Aquilegia flabellata var. pumila has few of the above mentioned flaws: it usually comes true from seeds, and the thick, leathery foliage won’t be affected by the leafminer (or very weak attack); all ‘flabellatas’ could be grown just for their handsome, fan-shaped foliage.

Aquilegia flabellata var.pumila – cute as a ‘button’ ; grown from seeds of course

 

A. flabelata ‘Nana Alba’ will be flowering soon…
Update – and it did, not a ‘nana’ but very beautiful!

 

Lost in translation – updates on germination requirements

,

Slowly, as I have the chance to try more species myself, and/or find reliable info, I work on making updates for the germination requirements on the Seeds shop. I already mentioned about Sanguinaria canadensis.

It is easy to ‘get lost in translation’ when reading about various types of morphophysiological dormancies, but a short summary for species from temperate regions that require warm/cold cycle for germination will be as follows:

This dormancy breaking requirement is naturally fulfilled by summer (high temperatures) followed by fall (lower warm temperatures) and winter (cold stratification). Note the need of high followed by low(er) warm temperatures.

Because of the collecting/shop logistics and peoples habit of buying seeds in late fall, this means that such species, when sowed in late fall/winter will need the whole next season to undergo these requirements, although otherwise they would not qualify in the ‘2 year germinators’ category.
So it goes: changed from require ‘cold stratification’ to ‘warm – cold stratification’:

Hydrophyllum virginianum
Hydrophyllum canadense
Aralia racemosa
Prosartes lanuginosa (moist packed seeds available this fall I hope)
Ilex verticillata

Hydrophyllum virginianum seedlings, seed sown fall 2015, too late for the warm treatment, germinated this spring (2017)

Prosartes lanuginosa: seeds sown after collecting in early September 2016 – germination right now (I only had about 9 seeds)

Other warm/cold germinators that we already know about and I already posted pictures (many require moist storage): most Corydalis, Allium tricoccum, Asarum canadense and europaeum, Saruma, Anemone quinquefolia and A. nemorosa, Dicentra (D. formosa in the featured image), Thalictrum thalictroides, Jeffersonia, Hepatica….

Corydalis nobilis seedlings