Sunflower species ID help - Ask Extension
Which sunflower species is this? At least 6' tall, narrow leaves, grows along creeks. Photos are from Clear Creek in Wheat Ridge. I've looked at Giant...
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Sunflower species ID help #807652
Asked August 23, 2022, 12:20 PM EDT
Which sunflower species is this? At least 6' tall, narrow leaves, grows along creeks. Photos are from Clear Creek in Wheat Ridge. I've looked at Giant, Sawtooth, & Nutall's.
Thanks!
Lorraine
Jefferson County Colorado
Expert Response
Hello Lorraine,
It would be most helpful if you could send additional photos showing a group of flowers growing together that shows the size and spacing. Also, a photo from a distance showing the area in which they are growing would help in identification.
Thank you.
It would be most helpful if you could send additional photos showing a group of flowers growing together that shows the size and spacing. Also, a photo from a distance showing the area in which they are growing would help in identification.
Thank you.
I only have one more photo, added.
Hi Lorraine -
Thanks for the additional photo. It's difficult to identify plants like sunflowers from photos as there are so many different types. Things like whether the stems are hairy, the leaves are toothed, and how long the leaf stalks are are key but hard to tell without a super macro look at the plant.
In looking at your photos, it appears that:
Take a look at Maximillian's Sunflower which is also a CO native sunflower. I have growing from seed in my yard (very easy to propagate and seeds readily available). It does look similar to your pictures, but mine is not so upright as it has not been getting much water. If yours is by Clear Creek it is possibly getting moisture from the Creek.
Colorado Master Gardener Clinician Annette
Thanks for the additional photo. It's difficult to identify plants like sunflowers from photos as there are so many different types. Things like whether the stems are hairy, the leaves are toothed, and how long the leaf stalks are are key but hard to tell without a super macro look at the plant.
In looking at your photos, it appears that:
- the leaves have somewhat short stalk attachments to the stems (called petioles in botanical lingo) and do not appear to be toothed (serrate) or are very finely serrate. The leaves also appear to slightly fold in the center and are somewhat upright and arched off the stems.
- I can't tell from photos if the stems are hairy or not - this is a key characteristic to identification.
Take a look at Maximillian's Sunflower which is also a CO native sunflower. I have growing from seed in my yard (very easy to propagate and seeds readily available). It does look similar to your pictures, but mine is not so upright as it has not been getting much water. If yours is by Clear Creek it is possibly getting moisture from the Creek.
- The book Flora of Colorado by Jennifer Ackerfield - a weighty but info-packed book that is the current authority for CO - lists Helianthus nuttallii but not the other two. This suggests that Giant and Sawtooth sunflowers are not commonly found naturally in Colorado - however someone could have planted them or spread seeds.
- https://www.wildflower.org/plants/search.php?start=0&pagecount=10 - This is a Texas resource but is a fantastic regional resource as well.
- https://www.minnesotawildflowers.info/search?scientific_name=Helianthus&wh - Minnesota resource that lists all three of your options.
- https://identify.plantnet.org/ - This is a versatile and free online and mobile plant ID resource. If you are in WiFi range you can take a picture from within the app. If not in range, take a picture on your phone and ID it later. You can select for the app to look at the flower, the leaves, the fruit, etc. and it will then give you options with the percentage of reliability for each. I often search first at the flower then go back and search for leaves with slightly different results.
Colorado Master Gardener Clinician Annette
Wow! Thanks for all the info! I'll look more closely at leaves next time I'm there. I have either the same or similar sunflowers growing in my yard from seed gathered near Ralson Creek, same habitat as Clear Creek.
I hadn't seen Maximilian as an option, will check it out.
I've been working on introducing more native plants to my yard for wildlife, I'm a passionate birder.
Thanks for the resources, there's another sunflower I'd like to identify, it's growing profusely all over the plains, an incredible sight today as I drove out to Jackson Lake SP. It's not Common Sunflower, the flowers are smaller, the leaves slender but it's about the same height.
Thanks again for your help!
Regards,
Glad you found in information helpful! I believe the sunflower found most places on plains and drier areas is Helianthus annus - an annual variety whereas the other varieties we discussed were perennials.
These new photos are of the sunflowers in my yard, grown from seed collected from flowers in a similar habitat.
Petioles are short, stalks are not hairy, leaves are long, narrow & smooth. Very little serration.
Lady Bird Johnson description says the leaves of Maximilian are course and hairy, mine are not.
I looked up Nutall's again, it seems to be the best match:
https://www.minnesotawildflowers.info/flower/nuttalls-sunflower
Definitely not Giant or Sawtooth so that narrows it down.
Thanks,
Lorraine
Thanks for the update Lorraine! One of the best parts of answering these questions is doing research and learning something new. Good luck!
