Flowers of the Sun - Helianthus, sunchokes and farmer ants
In October most plants are preparing for the impending cold, shunting their energy into their root systems and seeds -and then there are the sunflowers, cheery and bright, gaily obliging the last pollinators of the season. All 52 species of sunflowers are native to North America and belong to the genus Helianthus in the Asteraceae (Compositae) family. Many are perennials with gorgeous golden blooms, flowering effusively until late fall. As compared to the familiar annual sunflower (Helianthus annuus) with its gargantuan single flower head, the perennial Helianthus species typically have multiple mini sunflowers, creating a mass of buzzing sunshine.
These native sunflowers attract beneficial insects to the garden, such as parasitoid wasps and soldier beetles (pictured below in amorous embrace). The seeds also feed many songbirds; my maximilian sunflowers bring beautiful goldfinches to my garden. Some Helianthus species grow quite tall, providing shelter and cover for wildlife.
The maximilian sunflower (Helianthus maximiliani) has become very popular, especially in the southwestern US, as a native wildflower for xeric habitats. It is quite tall, with a tendency to fall over; so many gardeners cut it back mid-summer before it flowers to avoid staking and create more demure flowering branches. Native people ate/eat the roots; I have not tried them, but would love to hear from any readers who have.
The maximilian sunflower is a fun plant to observe ant/treehopper mutualism; see the photos below of ants "milking" treehopper larvae. Ants “farm” treehoppers similarly to the way they "farm" aphids. The ants protect the treehoppers from predators, and in turn suck up the sweet exudate, or "honeydew", produced from the leaf-sucking treehoppers.
The above photo was taken on the underside of a giant ragweed leaf (Ambrosia trifida, Asteraceae), another choice plant for observing this interesting insect dance. Pictured here are immature treehoppers, as opposed to the mature treehoppers, pictured above.
Swamp sunflower (Helianthus angustifolius) is another popular native perennial sunflower. As its name suggests, it prefers wetter habitats with well-drained soils, but it also thrives in average garden soil. There are shorter cultivars available, or the plants may be cut back as described above.
Jerusalem artichoke (Helianthus tuberosus) is a native sunflower with edible tubers. Its name certainly doesn’t sound American, but not to worry, it does have excellent family values and likes to dominate its surroundings.
When the first Europeans came to North America, they learned about this edible sunflower from the Native people, and promptly brought it back to Europe. Plant breeders selected for larger tubers with less nooks and crannies (the better to catch gritty dirt with, my dear). The Italian word for sunflower is girasole; you can imagine how, over time, girasole artichoke slowly permutated into Jerusalem artichoke.
Anyhow, these Euro-improved varieties are now commonly grown all over the world as an ornamental perennial vegetable. They can easily take over –just give them room to do their thing, and no one gets hurt.
The tubers are a good food for nourishing beneficial intestinal flora. They contain inulin, which cannot be digested by human enzymes, but is manna for our digestive minions. Foods high in inulin are called prebiotics (our beneficial digestive flora called probiotics). If you haven’t had the pleasure of eating Jerusalem artichoke, I recommend eating a small amount the first time, as they can be somewhat gassy. Some eaters have affectionately dubbed the tubers “fartichokes”. Other people, with more constructive dispositions, call the tubers sunchokes.
As the light grows dimmer, my choices are growing slimmer for seasonal flowers to feature. Lucky for you, my dear reader, (and perhaps myself too) I am heading to Florida for ten days, where I will likely find many unsuspecting flowers to photograph. I am taking my students to the Suwannee and Ichetucknee Rivers to learn about southeastern medicinal plants – yeehaw!
Just in case you were wondering, I am not above honoring special flower requests.