Tetraneuris torreyana |
Tetraneuris linearifolia |
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stone rubberweed, Torrey's four-nerve daisy |
fineleaf fournerve daisy, slimleaf actinea |
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Habit | Perennials, 2–15+ cm. | Annuals, 16–50+ cm. | ||||
Caudices | ± branched, branches notably thickened distally. |
none. |
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Stems | 1–30(–40), erect, unbranched. |
1–10, erect or ± decumbent, leafy, unbranched or branched distally. |
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Leaves | all basal, new leaves tightly clustered; blades (midribs usually pronounced) spatulate or oblanceolate to linear-oblanceolate, entire, glabrous or usually sparsely, sometimes moderately to densely, hairy, densely gland-dotted. |
basal and cauline, ± hairy, ± gland-dotted; basal blades spatulate to oblanceolate, entire or with 2–6 teeth or lobes; proximal cauline blades narrowly spatulate or oblanceolate to linear-oblanceolate, entire or with 2–6 teeth or lobes; mid blades oblanceolate to linear-oblanceolate to linear, 0.9–9.5(–16) mm wide, entire or with 1–2 teeth or lobes; distal blades narrowly oblanceolate to linear-oblanceolate to linear, entire or with 1–2 teeth or lobes. |
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Peduncles | (0.5–)2–15 cm, ± hairy proximally, almost always densely lanate distally. |
8–29 cm, ± hairy. |
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Involucres | 10–12 × 12–15 mm. |
5–10 × 7–15 mm. |
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Ray florets | 7–14; corollas 11–17 mm. |
9–25; corollas 8.2–16.8 mm. |
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Disc florets | 25–150+; corollas yellow, 4–4.7 mm. |
50–200+; corollas yellow, 1.6–3 mm. |
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Outer phyllaries | 4–8, 6–8.5 mm, margins (0.3–)0.5–1.2 mm wide, usually conspicuously scarious, abaxial faces ± hairy. |
8–21, 2.4–5.5 mm, margins 0–0.2 mm wide, not scarious or scarious, abaxial faces ± hairy. |
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Heads | 1–10(–40) per plant, borne singly. |
8–50(–80) per plant, borne singly or in corymbiform arrays. |
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Cypselae | 3–4 mm; pappi of 5–7 obovate to oblanceolate, aristate scales 3–4(–4.5) mm. |
1.5–2.6 mm; pappi of 4–8 obovate, often aristate scales 1–2.5 mm. |
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Tetraneuris torreyana |
Tetraneuris linearifolia |
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Phenology | Flowering May–Jun(–Sep). | |||||
Habitat | Roadsides, hillsides, slopes, open treeless areas, edges of woods | |||||
Elevation | (1300–)1700–3100 m ((4300–)5600–10200 ft) | |||||
Distribution |
CO; MT; UT; WY
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KS; NM; OK; TX; n Mexico
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Discussion | Varieties 2 (2 in the flora). Plants of Tetraneuris linearifolia morphologically intermediate between the two varieties are found in Bee, Duval, Live Oak, and McMullen counties, Texas. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 21, p. 451. | FNA vol. 21, p. 448. | ||||
Parent taxa | Asteraceae > tribe Heliantheae > subtribe Gaillardiinae > Tetraneuris | Asteraceae > tribe Heliantheae > subtribe Gaillardiinae > Tetraneuris | ||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Synonyms | Actinella torreyana, Hymenoxys depressa, Hymenoxys lapidicola, Hymenoxys torreyana, T. depressa | Hymenoxys linearifolia | ||||
Name authority | (Nuttall) Greene: Pittonia 3: 265. (1898) | (Hooker) Greene: Pittonia 3: 269. (1898) | ||||
Web links |