Cotyledons

The subject of Cotyledons (or “seed leaves”) is one that I’ve been eager to write about for some time now, they are surprisingly interesting if you give them the attention they deserve; So, let’s take a closer look!

Have you ever wondered where the initial nutrition for cannabis seedlings comes from? There is no yolk, nor a yolk-sac to facilitate a cannabis seed’s early feeding requirements, so, from where exactly do our canna-babies get their first serving much-needed munchies?

Okay, so maybe you haven’t been wondering that at all… which is fair enough… But, are you now?? I think it is a fascinating question since the first moments in a cannabis seedling’s life can influence much that is reaped in terms of rewards, or the lack thereof!

Are you getting curious yet? Keep reading… It is not much to digest and will surely benefit you when you think about caring for your next batch of cannabis seedlings.

What are Cotyledons?

Cotyledons (commonly referred to as “Seed Leaves“) are the first leaves that breach the soil surface, befalling just a few days after the victorious germination of any cannabis seed 🙂

Cotyledon leaves tend to differ both in shape and in size when compared to other leaves that follow throughout the later stages of the cannabis plant’s life-cycle and are often not regarded as “true leaves” by professionals within the cannabis industry.

Instead, growers and other cannabis enthusiasts often refer to these cotyledons as “seed leaves” or “embryonic leaves”, with the latter in reference to the fact that cotyledons form a significant part of the plant’s embryo!

Is this just a Cannabis thing?

We are not just talking about cannabis here; This is in-fact ubiquitous for all seed-bearing plants and is one of the physical markers often used by botanists to classify flowering plants.

For example, plants with a single Cotyledon leaf that appears shortly after germination are called monocotyledonous (or “monocots”) and plants with two cotyledons are referred to as dicotyledonous (“dicots”).

When are Cotyledons Formed?

Cotyledons are formed before seeds are germinated during a stage called embryogenesis, along with the root meristems and shoot meristems.

On the other hand, “true leaves” are formed post-embryonically (after germination) from the apical meristem which is responsible for generating subsequent aerial portions of the cannabis plant.

How long do Cotyledons stick around for?

This is kind of a tough question, as any kind of half-accurate prediction is based on a ton of variables…

On one hand, cotyledons can be ephemeral, lasting only a few days post-germination after-which they tend to wither away following depletion of the nutrition stores within.

On the other hand, however, cotyledons can likewise be reputably persistent whereby a lifespan of up to a year can be expected, which brings us to our next subtopic; photosynthesis…

Can Cannabis Dicots Photosynthesize?

The short answer – Yes!

Cannabis seedlings often yield dicots that can become photosynthetic and therefore may continue to produce nutrients for some time after the initial storage of pre-packed plant munches has been depleted.

In-fact, cannabis dicots often seem to function almost exactly like “true leaves” and are essentially found to be offbeat solely in shape.

Keep in mind: This does differ from strain to strain and in some cases, you may notice your plant’s cotyledons falling off after only a few short weeks, or even within the first month. Don’t stress, this is nothing to worry about and is also relatively common within rudarilis related cannabis strains (autoflowering seeds).

Epigeal VS Hypogeal

When it comes down to discussing cotyledons, the topic of epigeal VS hypogeal is often brought to light.

To clear things up, cannabis dicots are referred to as “epigeal” whereby the cotyledons expand during germination, pushing the shell of the seed right off, then popping through the surface of the soil and perhaps becoming photosynthetic.

On the other hand, hypogeal cotyledons remain below the surface of the soil and do not become photosynthetic, however, they are often used to store nutritional resources, as with acorns or some varieties of nuts.

Hypogeal cotyledons have nothing to do with cannabis plants but it is relatively on-topic wit this blog post, and I thought it was interesting, so I figured I’d add it in 🙂