Telling between Hieracium, Microseris, Hypochaeris, Krigia, and Taraxacum?

Posting out of mild frustration here, how are you supposed to identify these? Especially down to the species level?

For context, in my city the single most common flower by far is what I believe to be some type of hawkweed (Hieracium). It would be nice to know for sure, but it just doesn’t seem possible at a glance.

According to my Flora I’d have to look at “chaff,” pappus, and cypselae. I can’t for the life of me figure out what chaff is, and as for the other two, wouldn’t I have to dissect the flowers to check? Are there no other outwardly visible signs?

Are they too difficult to learn? Should I just leave them at the genus level?

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the pappus and cypselae are fruit terms in Asteraceae, not flower-related

The cypsela is the whole thing, the pappus is the ‘tail’
image

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That actually does help a lot. Would I simply have to wait until they go to seed in order to see the cypsela?

yes that’s correct

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and just to address this part, these are the bracts underneath the flower head. Here’s a slide from a presentation I gave last year showing bracts in a few Coronidium species

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That’s weird. Why is a third term besides bracts and phyllaries used for the same thing? When the key says “with chaff” or “without chaff” does that mean “presence of bracts” and “complete lack of bracts” respectively? Does “chaffy” mean “lots of bracts?”

In sunflowers, does chaff refer to the stuff around the seeds?

I’m not familiar enough with those taxa and the keys you’re using to offer a definitive answer, but from some brief reading, it seems like ‘chaff’ can be used to mean some different things depending on the taxon and context. Flora of North America says

Receptacles may bear paleae (i.e., some or all florets are individually subtended by a bractlet called a palea or receptacular bract). Collectively paleae have been called “chaff” and paleate receptacles have been described as “chaffy.”

This link then explains receptacle morphology a bit more

So probably in your case this is what the keys are referring to

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That slide is really helpful, @thebeachcomber. I wasn’t altogether sure what I should be looking for in the bracts before now. Note to self: macro or close-crops of flower head undersides. Thank you!

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Thank you so much!

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I’m not familiar with all of these genera but looking through their photos I can see some general differences. Taraxacum has larger single “flowers” on wide rubbery hollow stems that produce a milky sap when broken. They also tend to have more complexly lobed leaves, although that isn’t true for all sections (e.g. section Palustria).

In contrast Hieracium for example tends to have simpler smaller leaves, and a tall thin stem that branches out into a whole bunch of flowers at the top. Their flowers are also usually smaller than Taraxacum.

Looking through photos of Microseris, Hypochaeris, and Krigia they seem intermediate between the two in different ways, although more towards the Hieracium side of stem texture and flower size and shape (including number and texture of bracts and number of ray flowers).

In terms of species identification I don’t know about the other genera, but Taraxacum and Heiracium both do agamospermy which complicates species delineation (there are endless debates about dandelion taxonomy on the forum here…).

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Do you have a botanical glossary? I’d recommend https://press.uchicago.edu/ucp/books/book/distributed/K/bo23404403.html

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I only suggest you to get in contact with an expert for the genus Hieracium and to send photos and specimens. This genus is of course frustrating if you limit to make photos. Otherwise it would be better to give up with such plants.

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My understanding has always been the same as the Flora of North America definition - extra bracts attached directly to the receptacle among the flowers, neither phyllaries nor pappus.

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