Herbaceous plant terminology question

With respect to a flowering plant that has a stem and then stems coming off of the main stem, are those stems growing from the main stem also called stems, or are they called branches? Or is branch a term reserved for woody species like shrubs and trees? My terminology sources are failing me tonight.

I believe they are secondary stems, but I’m not totally sure. I don’t think branch is a botanical term.

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In fact you can call everything a shoot and not be wrong. Shrubs lack trunk, but have stems, for easier use you can call those branches as branches are stems that grow from lateral bud of a trunk or some other new growings of a plant.

I wonder if you mean the petiole? In botany, the petiole is the part that connects a leaf blade to a stem.

The leaf stalk. No, I may be talking about a panicle, Harris&Harris define that as “a branched racemose inflorescence with flowers maturing from the bottom upwards” or even a paniculiform, looks like a panicle but isn’t quite.

There is the main stem coming from the root. I think that’s the caulis. Then there is branching off of it. That’s where the flowers grow – the inflorescense(s). No flowers on the caulis. I’m looking for the terminology to say that the flowers only exist on those “branches.” Think Symphyotrichum lateriflorum. How do I describe to the average reader (like me) this concept? I can find a description in more technical terms, and want to use those in addition to a simplification, and “the flowers grow on tiny stalks (or no stalks) from branches off the main branch” is kinda it, but not, because I will use more botanical terms than that.

This photo of an S. lateriflorum shows it.

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branched inflorescence?

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http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=250067657
What about heads description there? (paniculiform array, etc.)

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I think you could use panicle to describe this plant, or maybe something in-between, like “racemose to paniculate.” A raceme is a shoot with single flowers placed along its length, and a panicle is basically a branched raceme.
This plant has lots of leaves present in the inflorescence, and the flowers occur toward the ends of the shoots, so it’s kind of in a gray are between a panicle and “multiple branches each ending in a raceme.” You could also modify the term to indicate that there’s more space between the flowers, such as “open panicle” or “loosely paniculate.”
It’s fine to use the term “branch” for the branches, but depending on the plant you might want to specify which branches you’re talking about. For example, in the photo it looks like there’s a shoot coming from the upper right of the frame to your thumb, and another coming from the right edge to your pinky. If those two shoots were from the same plant you might want to be clear whether you’re talking about those branches, or the smaller branches coming off the main stem.
From this photo I would say that flowers do occur on the main stem, especially looking at the shoot coming from the right edge of the frame.


Since we’re trying to be technical, I guess I’ll add that since this plant is in the Asteraceae the flowers are technically in a head. But, you can use the same terms for a grouping of heads as other plants get for a grouping of flowers. Also, it looks like there might be multiple heads growing in some of the axils, which could maybe change how the architecture is described, but it seems inconsistent, so I wouldn’t really worry about it.

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When you’re talking about a panicle, these stems are branches – secondary, tertiary branches, etc., if you really need to make this distinction.

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I love all of you. Will be processing your input today. Thank you so much for responding! I had follow-up questions before I slept. Hopefully, they’ll return.

Yes, that is helpful. I need a deeper understanding, or perhaps a different way of having it explained to me, before I can write something up in my own words that will appeal to most levels of readers.

Maybe that’s what it is?

After reading the responses and studying the terminology again, I see that panicle has these branches as a part of its definition. I’m getting thrown off by the term “corymb” which is in the existing Wikipedia article’s lead-in description. (Forgive the diagrams. I know I’m speaking to you who know more than me.) I don’t see any element of “corymb” at all for this plant, but maybe I’m missing something.

Raceme (Wikimedia Commons public domain):

Racemose corymb (Wikimedia Commons public domain):
256px-Schirmtraube_(inflorescence).svg

Panicle from Wikipedia: “Botanists use the term paniculate in two ways: ‘having a true panicle inflorescence’ (in the form of a panicle) as well as ‘having an inflorescence with the form but not necessarily the structure of a panicle’.” The latter being “paniculiform.”
500px-Inflorescences_Panicle_Kwiatostan_Wiecha.svg

Here’s a much larger example. This may better show how S. lateriflorum “works,” and I think if you stretch out any plant of this species that has matured enough to begin to branch to flower, you will see the same type of thing.

I took these photos at the end of September of about a 3 ft tall plant (which had disappeared presumably by deer within 48 hours of these pics). Documentation says they can get this tall, but I was at first fooled into thinking this was S. lanceolatum until I went in and studied my pics. You can see in the first photo the main stem – the caudex. There can be more than one on a plant for this species, but if there were on this plant, this photo doesn’t show it. I’ve drawn a blue arc to highlight it, and a red arc for each branch. It is only on these branches that flowerheads grow. This is what the documentation tells me, and my experience with a couple of dozen plants and hundreds of photos of others seems to confirm.

Closer:

This third photo, closeup of a the bottom branch node, you can see either another plant, stem, or branch in the background to the left (it’s the fuzzy green-ish stem). I don’t think it’s a stem off of this plant.

Finally, the flowerheads on the bottom branch of the tall plant:

This plant doesn’t show any significant compound branching (secondary, tertiary, etc., as @sedgequeen states), just the peduncles and their accompanying little sessile leaves (which I think have a special name that I forget). But then you can see in the middle of the image, top of the branch, three flowerheads coming from what would appear to be one peduncle, but is most likely another little branch. I think you, @kweitemier, took note of some on the other plant that were growing from axils. I see that here as well.

I have seen the diagram of the panicle, know that you can be a panicle or just look like a panicle - paniculiform. H&H define a true panicle as flowers maturing from the bottom toward the top. I would presume in this case for this species, we are saying it’s paniculiform because it looks like it’s paniculate, but the flowers mature when they want to regardless of their location on the branch. Is that right?

Some of my statements are probably questions seeking confirmation or correction. I know I ask a lot of this group. Thank you all so much in advance, again.

Just to be a contrarian, I’m going to say the inflorescences on your first photo are simple and axillary, arranged along the leaf-axils of the terminal branchlets.

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You can have a panicle with branches that are racemes or spikes. You can have lots of other possible combinations.

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The entire plant is a branched inflorescence, right?

@kweitemier @arboretum_amy @teellbee @sedgequeen @melodi_96 and any other interested parties:

I have this (with source and other notes and links I have left out of this paste):

Flower heads grow in racemose paniculiform arrays, secund on the upper sides of the branches. These horizontally branched inflorescences are up to 15 cm (6 in) wide and 25 cm (10 in) long.

Would you say this is accurate and complete with respect to how and where the flower heads grow on the calico aster? Could I add anything to it?

Inflorescence is the flowering part?

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Yep! Sure is.