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Serpentine Sunflower

Helianthus bolanderi Gray

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provided by eFloras
Helianthus bolanderi and H. exilis form a closely related pair of sister species that share the distinctive feature of having the middle teeth of the paleae glabrous and relatively elongated, surpassing the disc florets. As treated here, H. bolanderi corresponds to the "valley weed race" (C. B. Heiser 1949; L. H. Rieseberg et al. 1988); it is separated from the "serpentine foothill race," here recognized as H. exilis. Heiser proposed that H. bolanderi originated through hybridization between H. annuus and H. exilis; molecular studies by Rieseberg et al. do not support this scheme. In an ironic twist, it appears that H. bolanderi may be undergoing "genetic assimilation" through hybridization with H. annuus (S. E. Carney et al. 2000).
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Missouri Botanical Garden, 4344 Shaw Boulevard, St. Louis, MO, 63110 USA
bibliographic citation
Flora of North America Vol. 21: 143, 149, 150 in eFloras.org, Missouri Botanical Garden. Accessed Nov 12, 2008.
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Description

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Annuals, 60–150 cm. Stems erect, hispid to hirsute. Leaves mostly cauline; mostly alternate; petioles 1–4 cm; blades lance-linear or lance-ovate to ovate, 3–15 × 2–6 cm, bases cuneate to truncate, margins usually serrate, abaxial faces sparsely hirsute, gland-dotted . Heads 1–3. Peduncles 3–13 cm. Involucres hemispheric, 17–25 mm diam. Phyllaries 10–18, usually lanceolate to lance-ovate, 9–27 × (3–)3.5–5 mm (often surpassing discs), apices gradually attenuate, abaxial faces hirsute. Paleae 9.5–10.5 mm, 3-toothed (middle teeth subulate, surpassing discs, apices glabrous). Ray florets 12–17; laminae 14–20 mm. Disc florets 75+ (discs usually 2+ cm diam.); corollas 5–7 mm, lobes usually reddish; anthers dark, appendages dark (style branches reddish). Cypselae 3.5–4.5 mm, glabrate; pappi of 2 lanceolate scales 1.7–3 mm. 2n = 34.
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cc-by-nc-sa-3.0
copyright
Missouri Botanical Garden, 4344 Shaw Boulevard, St. Louis, MO, 63110 USA
bibliographic citation
Flora of North America Vol. 21: 143, 149, 150 in eFloras.org, Missouri Botanical Garden. Accessed Nov 12, 2008.
source
Flora of North America @ eFloras.org
editor
Flora of North America Editorial Committee
project
eFloras.org
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eFloras

Brief Summary

provided by EOL authors
Helianthus bolanderi (synonym: Helianthus exilis) is a rare forb species endemic to California's North Coast Ranges. This plant is restricted to areas within serpentine outcrops, where it occurs in insular metapopulations.

Also known as Serpentine sunflower, this annual forb achieves a height of 60 to 150 centimeters. The erect stems are hispid to hirsute. Leaves are chiefly cauline and typically alternate. Leaf petioles are one to four centimeters in length.
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Helianthus bolanderi

provided by wikipedia EN

Helianthus bolanderi is a species of sunflower known by the common names Bolander's sunflower[1] and serpentine sunflower.[2] It is native to California and Oregon, where it grows mainly in mountainous areas, often in serpentine soils. It has been found from southwestern Oregon as well as in northern and central California as far south as Santa Cruz County, with reports of a few isolated populations in southern California (some of them from urban areas and very likely cultivated or escaped specimens).[3][4]

This wild sunflower is an erect annual reaching heights over a meter (40 inches). It has a hairy, rough stem with leaves lance- or oval-shaped, usually pointed, sometimes serrated along the edges, and 3 to 15 centimeters (1.2-6.0 inches) long. The inflorescence holds one or more flower heads, and each plant may have many inflorescences growing along the full length of the stem. The flower head has a cup of long, pointed phyllaries holding an array of bright yellow ray florets each one to two centimeters (0.4-0.8 inches) long around a center of yellow to dark purple or reddish disc florets. The achene is 3 to 5 millimeters (0.12-0.20 inches) long.[5]

References

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Helianthus bolanderi: Brief Summary

provided by wikipedia EN

Helianthus bolanderi is a species of sunflower known by the common names Bolander's sunflower and serpentine sunflower. It is native to California and Oregon, where it grows mainly in mountainous areas, often in serpentine soils. It has been found from southwestern Oregon as well as in northern and central California as far south as Santa Cruz County, with reports of a few isolated populations in southern California (some of them from urban areas and very likely cultivated or escaped specimens).

This wild sunflower is an erect annual reaching heights over a meter (40 inches). It has a hairy, rough stem with leaves lance- or oval-shaped, usually pointed, sometimes serrated along the edges, and 3 to 15 centimeters (1.2-6.0 inches) long. The inflorescence holds one or more flower heads, and each plant may have many inflorescences growing along the full length of the stem. The flower head has a cup of long, pointed phyllaries holding an array of bright yellow ray florets each one to two centimeters (0.4-0.8 inches) long around a center of yellow to dark purple or reddish disc florets. The achene is 3 to 5 millimeters (0.12-0.20 inches) long.

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Wikipedia authors and editors
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wikipedia EN