Solidago flexicaulis | Family Asteraceae (Aster)
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| Zigzag goldenrod along a woodland edge in August. |
Zigzag goldenrod, also called big leaf goldenrod, is a native perennial of forest edges and openings. It’s literally a late bloomer, flowering from August into October with narrow, upright clusters of yellow-gold flowers at the top of the plant and from the upper nodes.
Each “flower” is actually a group of small flowers in a head inflorescence, an arrangement typical of plants in the aster family. The central flowers, called disk flowers, have small, recurved, yellow petals that are easiest to see with a magnifying lens. Around them are several ray flowers, so called because each bears a single, petal-like ray. Zigzag goldenrod heads typically have 3-5 rays at their peak.
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| Left: A single head of small flowers. Two rays are visible. The "spears" emerging from the flowers are stamens and pistils, the reproductive parts of the flower. Right: A single head dissected to show disk and ray flowers. The white threads at the base of the flowers are a group of modified sepals called a pappus. |
At the base of either kind of flower are white, thread-like, modified sepals, together called the pappus. Unlike the leafy or petal-like sepals many plants have, these tiny filaments persist after flowering. They are attached to the top of small, linear fruits called achenes (ah-KEENS). A single plant produces hundreds (thousands?) of them, each carried by wind with the help of its parachute-like pappus.
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| Left: The fruits on this zigzag goldenrod are ready to catch the wind. Right: Individual achenes, each just a millimeter or two long and topped with a spreading pappus. |
Even before it flowers, zigzag goldenrod is easy to recognize. As its name suggests, the stems typically zig and zag from one node to the next. The pattern is subtle, but it’s still a good identifying characteristic.
The name “big leaf” refers to the lower leaves, which are
egg-shaped and up to 4 inches wide and 6 inches long. Their margins (edges) are
coarsely toothed and their petioles are winged, especially where they meet the
leaf blades. Farther up the stem, the leaves are smaller and lance shaped.
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| Left: A stem with a typical zig zag pattern. Upper right: Lower and middle leaves are egg shaped and sharply toothed. Lower right: Upper stem leaves are lance shaped, becoming smaller up the stem. |
Zigzag goldenrod spreads not just with seeds but also with rhizomes to form colonies. It isn’t as aggressive as Canada goldenrod, but patches will expand noticeably in a few years. That’s helpful where cover is desired but not so helpful in formal gardens, where plants are often preferred to stay in place.
Zigzag goldenrod is pollinated by a variety of insects,
including bees, flies, wasps and butterflies. Goldenrods in general, along with
asters, are important sources of food for pollinators late in the season.
Goldenrods also host insect larvae, such as the colorful caterpillar of the
brown-headed owlet moth.
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| Left: A bumble bee pollinates zigzag goldenrod while gathering nectar and pollen. Right: A caterpillar of the brown hooded owlet moth feeds on zigzag goldenrod. |
It’s hard to fault zigzag goldenrod for anything, but goldenrods in general have a reputation for causing seasonal allergies. Their pollen, however, is relatively heavy and sticky, ideal for attaching to insect bodies but not for catching the wind. The pollen of common ragweed and giant ragweed, however, is light, dry and wind-borne, and it’s released from mid-summer to mid-fall, about the same time as goldenrods. Also, ragweed grows in the same dry, sunny habitats that favor some goldenrods, so the latter gets a bad rap.
It’s undeserved. No need for tissues to enjoy zigzag goldenrod.
Just a semi-shady spot and an appreciation for this golden yellow pollinator magnet.
References
Board
of Water and Soil Resources
