Dimeresia howellii |
Asteraceae tribe heliantheae |
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dimeresia, doublet |
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Habit | Herbs annual, cespitose, often acaulescent; taprooted. | |
Stems | 0 or ? 3 cm; simple or with whorls of several branches, glabrous. |
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Leaves | basal and cauline, crowded, usually whorled below; opposite above, spatulate to lanceolate; ovate, or broadly elliptic, 4–35 mm; margins entire; tips acute to obtuse; surfaces abaxially glabrous or lightly villous, sometimes obscurely punctate-glandular, sessile or petioles 1–12 mm. |
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Inflorescences | 1–many heads in 1–10 dense clusters. |
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Involucres | cylindric to obconic, 4–6 × 2(4) mm. |
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Receptacles | minute; paleae 0. |
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Florets | (1)2–3; corolla tubes 1.5–2 mm, white or purple; lobes 5, spreading, 0.5–2 mm, white or purple at base; stamens partly or wholly exserted; stigmas included. |
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Phyllaries | 2–3 in 1 equal series; erect, deciduous in fruit, broadly elliptic or ovate, obscurely parallel-veined; tips obtuse; surfaces glabrous. |
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Fruits | cylindric or oblanceolate, tapering to base, flattened, truncate, 2.5–3 mm; black, glabrous, with 14–20 inconspicuous ribs, pappi of basally connate, plumose scales or flattened bristles, deciduous, 3–4 mm, white. |
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Heads | discoid; erect, sessile or peduncles 0–1 mm; surfaces glabrous to woolly-villous. |
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2n | =14. |
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Dimeresia howellii |
Asteraceae tribe heliantheae |
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Distribution | ||
Discussion | Rocky ridges, hillsides, talus slopes, sagebrush flats. Flowering May–Jul. 700–2800 m. BR, BW, ECas, Owy. CA, ID, NV. Native. |
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Source | Flora of Oregon, volume 2, page 244 Kenton Chambers |
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