Helianthus debilis |
Helianthus eggertii |
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cucumberleaf sunflower, weak sunflower |
Eggert's sunflower |
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Habit | Annuals or perennials, 30–200 cm (taprooted). | Perennials, 30–200+ dm (rhizomatous). | ||||||||||||||||
Stems | decumbent to erect, glabrous, hirsute, or puberulent. |
erect, glabrous (distinctively bluish, glacous). |
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Leaves | mostly cauline; mostly alternate; petioles 1–7 cm; blades deltate-ovate, lance-ovate, or ovate, 2.5–14 × 1.8–13 cm, bases cordate to truncate or broadly cuneate, margins subentire to serrate, abaxial faces glabrate to hispid, not gland-dotted. |
cauline; all or mostly opposite; sessile; blades (1-nerved) lanceolate to lance-ovate, 7–16.5 × 1.5–3.5 cm, bases cuneate, margins entire or serrulate, faces glabrous (abaxial) or strumose (adaxial), gland-dotted. |
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Peduncles | 9–50 cm. |
1–4 cm. |
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Involucres | hemispheric, 10–22 mm diam. |
hemispheric, 10–25 mm diam. |
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Ray florets | 11–20; laminae 12–23 mm. |
10–18; laminae 15–20 mm. |
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Disc florets | 30+; corollas 4.5–5 mm, lobes usually reddish, sometimes yellow; anthers dark, appendages dark (style branches usually reddish, rarely yellow). |
70+; corollas 5–7 mm, lobes yellow; anthers dark, appendages dark or ± yellowish. |
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Phyllaries | 20–30, lanceolate, 8–17 × 1–3 mm, apices acute to long-attenuate, abaxial faces glabrous or ± hispid, not gland-dotted. |
30–38, lanceolate, 12–16 × 3.5–4.5 mm, (margins ciliate) apices acuminate, abaxial faces glabrate, not gland-dotted. |
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Heads | 1–3. |
1–5. |
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Cypselae | 2.5–3.2 mm, glabrous or sparsely hairy; pappi of 2 lanceolate or lance-linear scales 1.2–2.5 mm. |
4–6 mm, glabrous; pappi of 2 aristate scales 3–4 mm plus 0–1 deltate scales 0.5–1 mm. |
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Paleae | 7.5–8 mm, apices 3-toothed (middle teeth acuminate, usually glabrous or hispid, sometimes ± villous or bearded). |
9–11 mm, entire or ± 3-toothed (apices deltate). |
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2n | = 102. |
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Helianthus debilis |
Helianthus eggertii |
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Phenology | Flowering late summer–fall. | |||||||||||||||||
Habitat | Open barrens, open oak-hickory woodlands | |||||||||||||||||
Elevation | 100–300 m (300–1000 ft) | |||||||||||||||||
Distribution |
AL; CT; FL; GA; LA; MA; MD; MI; MS; NC; NH; NY; PA; RI; SC; TX; VA; VT; WV
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AL; KY; TN |
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Discussion | Subspecies 5 (5 in the flora). C. B. Heiser (1956) placed 8 subspecies in Helianthus debilis; he noted that alternative taxonomic treatments might recognize these in as many as three species, or expand the single species to include H. petiolaris. Later, Heiser et al. (1969) separated three of the subspecies as H. praecox. Isozyme data (R. P. Wain 1982, 1983; L. H. Rieseberg and M. F. Doyle 1989) show that all are closely related. Documented hybridization with H. annuus further complicates the situation. The treatment by Heiser et al. is followed here. Helianthus debilis is adventive beyond the Atlantic and Gulf coasts of the United States. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Helianthus eggertii is similar to H. strumosus and H. laevigatus; it is distinguished by the distinctive blue coloration of stems and leaves and by the leaves usually 1-nerved, in contrast to the 3-nerved condition typical for the genus. It is listed federally as an endangered species; R. L. Jones (1994) found it to be more common than was previously thought, and it is now in the process of being removed from the federal list. of conservation concern (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 21, p. 150. | FNA vol. 21, p. 159. | ||||||||||||||||
Parent taxa | Asteraceae > tribe Heliantheae > subtribe Helianthinae > Helianthus | Asteraceae > tribe Heliantheae > subtribe Helianthinae > Helianthus | ||||||||||||||||
Sibling taxa | ||||||||||||||||||
Subordinate taxa | ||||||||||||||||||
Name authority | Nuttall: Trans. Amer. Philos. Soc., n. s. 7: 367. (1841) | Small: Fl. S.E. U.S., 1267, 1340. (1903) | ||||||||||||||||
Web links |