| EwA HighlightsAugust 24, 2024 |
| Hello everyone!
Thanks for reading the August 24th EwA highlights. Last week, with summer approaching its close, we took a look at dragonflies and damselflies, delightful insects to observe throughout the season. This week, we look forward to one of my favorite types of plant to see in the late summer and fall: the American asters (genus Symphotrichum). |
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| 📸 Symphotrichum falls within the large family Asteraceae, one of the largest families of plants, with about 32,000 currently described species. The distinguishing feature of this family is their composite flower heads, which are actually made up of many smaller flowers. There are two types of flowers making up these flower heads: disc florets which make up the central disc of the head, and ray florets which are what appear to be the “petals” of the head. In this image, the disc florets are yellow and the ray florets are purple.
EwA iNaturalist Record (© Claire O’Neill · Somerville, MA · September 26, 2023)
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| American asters can vary widely in the size of these flower heads. Some, like the new england aster (Symphotrichum novae-angliae) above, can have as many as 100 ray florets; others, like this calico aster (Symphotrichum lateriflorum) have as few as 10. Despite these sometimes-stark differences, they can be quite hard to identify due to these species’ eagerness to hybridize. To get a sense of how many varieties you might encounter, check out all the varieties and naturally-occurring hybrids of this species.
EwA iNaturalist Record (© Laura J. Costello · Orange, VT · September 11, 2022) |
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| Of course, one of the reasons these flowers are so beloved is their tendency to persist late into the fall. It’s not unheard of for a Symphotrichum species to still have flowers into late November or even early December. Each species and location will have its own phenology, but this tendency makes American asters a valuable late food source for many pollinators. For instance, Claire observed this common blue wood aster (Symphotrichum cordifolium) on November 20th of last year, presumably still producing nectar.
EwA iNaturalist Record (© Claire O’Neill · Somerville, MA · November 20, 2023)
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| Once they do finally go to seed, these plants (and others in Asteraceae) are often distinguishable by their fluffy seed heads. The flower heads, full of scores of little flowers, create scores of tiny wind-dispersed seeds. So even if you’re observing them in the winter, you can anticipate pretty well where there will be a beautiful patch of flowers next year.
EwA iNaturalist Record (© gsarajg · Cambridge, MA · November 15, 2021)
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| 📅 EwA Upcoming Public Events Ewa Field Events » Check the EwA Summer [ Event details and registration » ] Don’t miss some great opportunities to follow the rhythm of the season in our local habitats and in the local wildlife! Space is limited for all our field events. Wildlife ethics is important to us and we seek to avoid putting the pressure on natural habitats which large gatherings unavoidably do. We are asking our audience to register-and-commit (or cancel when you know you can’t come) to avoid no-shows.
EwA Fieldwork (and Resources) It’s a great time to join our monitoring programs. Check EwA’s Volunteer Program Calendar 📅 to know when things happen. And if a session is of interest to you, don’t hesitate to reach out to get the rendezvous location.
📅 EwA Sites Map | 🌱 Site Protocols and Guides · Field Rosters · Field Notes » All here! | ℹ️ More about EwA’s Citizen Science Program » Here
❓ Do you have any questions? Don’t be shy. Just email me or reply to this thread.
That’s all for this week—hope you have a good one!
-Mike |
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