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Small Tarweed

Madia exigua (Sm.) Greene

Comments

provided by eFloras
Madia exigua occurs in seasonally dry situations in much of western North America outside the warm deserts. Morphologically, M. exigua is somewhat similar to Hemizonella minima, which (unlike M. exigua) has subumbellate arrays of heads and obcompressed, sparsely hairy ray cypselae.
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Missouri Botanical Garden, 4344 Shaw Boulevard, St. Louis, MO, 63110 USA
bibliographic citation
Flora of North America Vol. 21: 296, 297, 305, 306 in eFloras.org, Missouri Botanical Garden. Accessed Nov 12, 2008.
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Flora of North America @ eFloras.org
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Flora of North America Editorial Committee
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eFloras.org
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Description

provided by eFloras
Plants 1–30(–50) cm, self-compatible (heads not showy). Stems hirsute and glandular-pubescent, glands yellowish or purple, lateral branches seldom surpassing main stems. Leaf blades linear, 0.2–4 cm × 0.5–2 mm. Heads in open, corymbiform arrays (peduncles ± filiform). Involucres depressed-globose, 2.5–5 mm. Phyllaries ± hirsute and glandular-pubescent as well, glands golden yellow, apices ± erect, sulcate. Paleae mostly persistent, connate 1/2+ their lengths. Ray florets 1–8; corollas pale yellow, laminae 0.7–1 mm. Disc florets 1(–2), bisexual, fertile; corollas 1–1.8 mm, glabrous; anthers yellow to brownish. Ray cypselae black or brown, dull, compressed (strongly arcuate), beaked (beaks adaxially offset, curved). Disc cypselae obovoid, weakly compressed. 2n = 32.
license
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: 296, 297, 305, 306 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
original
visit source
partner site
eFloras

Synonym

provided by eFloras
Sclerocarpus exigua Smith in A. Rees, Cycl. 31: Sclerocarpus no. 3. 1815
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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: 296, 297, 305, 306 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
original
visit source
partner site
eFloras

Brief Summary

provided by EOL authors
Madia exigua is a wildflower that occurs in certain parts of western North America, from Baja California to British Columbia and east to Montana. Typical habitats are somewhat arid grasslands and open woodlands.

Also known as Small tarweed, this aromatic annual achieves a variable height of up to 50 centimeters. Stems are slender, simple below to branched throughout, more or less bristly or soft-hairy, especially below. The leaves are one to four centimeters long, strigose to somewhat bristly. The inflorescence heads manifest in open, generally flat-topped to panicle-like clusters. Flowers are pale yellow.
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Madia exigua

provided by wikipedia EN

Madia exigua is a species of flowering plant in the family Asteraceae known by the common names small tarweed and threadstem madia.

Range

Madia exigua is native to western North America from British Columbia to Baja California, where it grows in many types of dry habitat outside the deserts.

Description

Madia exigua is an aromatic annual herb growing up to half a meter (20") tall, its slender stem coated with hairs, large stalked resin glands, and sometimes bristles. The rough-haired leaves are 1 to 4 centimeters (0.4 to 1.6") long.

The inflorescence is an array of clustered flower heads on thin, stiff peduncles. Each head has an involucre of phyllaries shaped like a top. The phyllaries are coated in knobby yellow resin glands. At the tip of the inflorescence are minute yellowish ray florets each under a millimeter long, and one or two yellow disc florets. The fruit is an achene with no pappus.

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wikipedia EN

Madia exigua: Brief Summary

provided by wikipedia EN

Madia exigua is a species of flowering plant in the family Asteraceae known by the common names small tarweed and threadstem madia.

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Wikipedia authors and editors
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