| Oregon Flora Image Project | |
| Senecio sylvaticus L. | woodland groundsel - exotic,
naturalized Asteraceae: Senecioneae |
Click on an image for a larger version. All images © Gerald D. Carr unless otherwise noted.
| Bellfountain Rd., at SW Nicole Drive, N44.46699, W123.33710, SW of Corvallis, Benton Co., OR, 6/7/2008 | Bellfountain Rd., at SW Nicole Drive, N44.46699, W123.33710, SW of Corvallis, Benton Co., OR, 6/7/2008 | Bellfountain Rd., at SW Nicole Drive, N44.46699, W123.33710, SW of Corvallis, Benton Co., OR, 6/7/2008 |
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| Bellfountain Rd., at SW Nicole Drive, N44.46699, W123.33710, SW of Corvallis, Benton Co., OR, 6/7/2008 | Clear-cut on W side of Hwy 34, 3.1 mi. SW of jct. with Marys Peak Rd., 600 ft. elev., N44.44030, W123.52941, Benton Co., OR, 9/29/2021 | ||
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| ABOVE: The five images from "Bellfountain Rd". and one from "Clear-cut" illustrate typical morphology for this species. The "Clear-cut" image at the lower right shows two stem sections from a single plant at an unusually early stage of development for this late in the growing season. The shoot at the far right in the same image was taken from the plant depicted in the two images below. |
| Clear-cut on W side of Hwy 34, 3.1 mi. SW of jct. with Marys Peak Rd., 600 ft. elev., N44.44030, W123.52941, Benton Co., OR, 9/29/2021 | Clear-cut on W side of Hwy 34, 3.1 mi. SW of jct. with Marys Peak Rd., 600 ft. elev., N44.44030, W123.52941, Benton Co., OR, 9/29/2021 | ||
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| ABOVE: The single plant depicted in the two images above bears flowering heads of two markedly different morphologies that are further characterized in the following images. Most of the many plants at this site that were at a comparable developmental stage also exhibited both types of heads. This phenomenon was discovered by Barbara Lachenbruch, who guided Dick Halse and me to this site and who has also observed its occurrence in additional populations of this species at other sites. BELOW: Left -- One large, apparently "normal" shoot and several randomly sampled smaller snippets, each exhibiting a mixture of "normal" and "aberrant" flowering heads. Right -- "Aberrant" and "Normal" heads near anthesis. Note: "aberrant" head on left with involucre cupulate vs. cylindrical, shorter than "normal", phyllaries weakly united; pappus shorter, disheveled, spreading; corolla lobes strongly exserted. |
| Clear-cut on W side of Hwy 34, 3.1 mi. SW of jct. with Marys Peak Rd., 600 ft. elev., N44.44030, W123.52941, Benton Co., OR, 9/29/2021 | Clear-cut on W side of Hwy 34, 3.1 mi. SW of jct. with Marys Peak Rd., 600 ft. elev., N44.44030, W123.52941, Benton Co., OR, 9/29/2021 | ||
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| Clear-cut on W side of Hwy 34, 3.1 mi. SW of jct. with Marys Peak Rd., 600 ft. elev., N44.44030, W123.52941, Benton Co., OR, 9/29/2021 | Clear-cut on W side of Hwy 34, 3.1 mi. SW of jct. with Marys Peak Rd., 600 ft. elev., N44.44030, W123.52941, Benton Co., OR, 9/29/2021 | Clear-cut on W side of Hwy 34, 3.1 mi. SW of jct. with Marys Peak Rd., 600 ft. elev., N44.44030, W123.52941, Benton Co., OR, 9/29/2021 |
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| ABOVE: Features of "Aberrant" Heads and Florets. Note: in addition to features cited above, ovaries much larger than normal (compare images below), ovaries also observed to be much thicker walled; corolla tubes much shorter than "normal" (compare images below). BELOW: Left: -- "Normal" florets, Note: pappus bristles perfectly straight and pressed to the corolla tube (spreading only if the florets are removed from the involucre or upon fruit maturation); corolla tube shorter than phyllaries. Right: -- "Aberrant" florets (left & right), "Normal" floret (center), Note obvious differences in pappus features, ovary size, and corolla tube length. As seen here, "Normal" florets often appear to exceed "Aberrant" florets in overall length by about 1 mm. |
| Clear-cut on W side of Hwy 34, 3.1 mi. SW of jct. with Marys Peak Rd., 600 ft. elev., N44.44030, W123.52941, Benton Co., OR, 9/29/2021 | Clear-cut on W side of Hwy 34, 3.1 mi. SW of jct. with Marys Peak Rd., 600 ft. elev., N44.44030, W123.52941, Benton Co., OR, 9/29/2021 | ||
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