How can I tell whether my marigolds are edible calendula?

[Dilbertian]

My mad keen gardener mum always called marigolds calendula (she's not English) and used them as edible plants.

To my surprise, I have since learned that not all marigolds are calendula, and so not all are edible. These are the first I've planted and they've come up not more than 6" high - much smaller than dm's. How do I know whether they are edible calendula or the other sort of marigolds?

Those are very pretty but not calendula. They do get called marigolds though, which can be confusing

Here: https://www.rocketgardens.co.uk/product/veg-plants/for-a-beautiful-plot/calendula/

they self seed really well, you can also collect the seed to sow or share

Bother. That means they are the Wrong Sort.

Yup. But pretty!

Those are French ones aren't they? Ok just found this which is very helpful.
https://letseataforest.com/tag/african-marigold/

I used to eat nasturtiums, but you need to look under the leaves, in case blackfly is clustered there.

nasturtiums are great, kind of peppery. Mine haven’t really taken off this year

Do people refer to nasturtiums as marigolds too? Crikey. Thank goodness for Latin names!

French marigolds are in the tagetes family, not the calendula family.

The edible marigolds are calendula officinalis

These were sold as 'marigolds'. I don't think there was any Latin name on the packaging. If I'd known then about the callendula/tagetes business, I wouldn't have bought them. They were an impulse buy.

Oh well. They're pretty enough. Will they self-seed?

Yes they will. The previous owner of my house had them and they come up everywhere.

No, not quite. Both Tagetes and Calendula are in the same family, the daisy family, Asteraceae. But they are different genera. So French and African marigolds are both in the genus Tagetes, and pot marigold is in the genus Calendula.

A bit like thyme and sage - different genera, Thymus and Salvia, but same family Lamiaceae.

They can be used as a companion plant, to deter whitefly from neighbouring plants. So they do have some virtues

I like self-seeding plants with pretty flowers 😄

Yes I know, but I thought the OP and others would understand the term 'family' more readily than the official Latin terminology.

The correct answer to "are they edible?" is to feed some to your DH and see what happens...

yes, I sympathise with that. If only there were some term that we could use that meant related/not closely related that wasn't also a botanical technical term. There's also confusion in people knowing, for example, that potato, green pepper, tomato , deadly nightshade are in the "nightshade family" (something which has been given a lot of prominence by food writers), and therefore feeling that Tagetes and Calendula are more distantly related than potato and tomato.

Of course my argument isn't helped by the fact the whole botanical classification is a snapshot of an evolutionary process, so with some species only recently separated and some a long way distant. But even so, being in the same family implies at the very least a similarity in flower structure, and in general it's more difficult to hybridise between genera than it it is between species of the same genus, so I think genus and family as technical terms do have practical use, and it certainly enhances one's understanding to have a feeling of where species stand in relation to each other, same or different genera, same or different family.

in general it's more difficult to hybridise between genera

Does this mean that I can plant calendula among the tagetes and not worry about them creating some inedible hybrid?

Yes 😂

These are French marigolds (tagetes). You want English marigold (calendula). Pop some seeds down now, you may get some nice late flowers. If you like pretty and easy, your other friends are nasturtiums (start them inside but once it warms up can't stop them), nigella, borage (flowers edible), petunias (pub hanging basket flowers)

Those (French) marigolds are insanely easy to grow from seed, OP. Keep a few dry seed heads until next year and they will germinate well and give you loads of free flowers.

They were my introduction to gardening when I was 6 years old.

The edible calendula are sometimes called pot marigolds, and are the ones with flat flowers - like big orange daisies.

Large 'mop' heads are African marigolds (I think alsonedible, but do double check that).

Your little frilly ones are French marigolds and definitely not edible.

Tagetes are edible
https://theflowerdeli.co.uk/flowers/tagetes

I was just about to post that!😄 I used to grow both Calendula (English marigold) and tagetes (French marigolds) as edible petals for a local restaurant - as it was a 2 Michelin star restaurant and the head chef and I had done plenty of research on edible flowers, we used them with confidence