Viguiera dentata (Cav.) Spreng. (redirected from: Viguiera triquetra)
Family: Asteraceae
[Encelia montana ,  more...]
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Perennials, 100-200 cm. Leaves opposite (proximal) or alternate (distal); petioles 10-55 mm; blades ovate or rhombic-ovate to lance-ovate or lanceolate, 3.5-12.5 × 1-8 cm, margins serrate or serrulate, faces strigose. Heads usually 3-9+ in ± corymbiform arrays. Peduncles 3-14 cm. Involucres 11-18 × 7-10 mm. Phyllary apices abruptly narrowed to acuminate or spatulate (phyllary bases broad, indurate, apices herbaceous). Paleae 6.5 mm, apices prominently cuspidate. Ray florets 10-14; tubes 1 mm, laminae 7-15 mm. Disc florets 50+; corollas 3-4 mm (staminal filaments hairy). Cypselae 3.5-3.8 mm, ± strigose; pappi of 2 lacerate, aristate scales 2.2-2.8 mm plus 2-4 lacerate scales 0.5-0.7 mm. 2n = 34.

Flowering Jun-Oct. Dry slopes and canyons, fields, roadside ditches; 100-2300 m; Ariz., N.Mex., Tex.; Mexico; West Indies (Cuba); Central America.

Viguiera dentata is widespread and variable. It is unique in Helianthinae in the hairy staminal filaments. The name V. dentata var. lancifolia S. F. Blake has been used for plants from Mexico.

FNA 2006, Martin and Hutchins 1980, MacDougall 1973, Allred and Ivey 2012

Duration: Perennial

Nativity: Native

Lifeform: Subshrub

General: Perennial herbs, 1-2 m tall; stems branched, usually covered with short stiff hairs.

Leaves: Opposite below, alternate above, on petioles 1-6 cm long; blades rhombic-ovate to lance-ovate or lanceolate, 3-13 cm long by 1-8 cm wide, the margins entire or toothed, the surfaces covered in short stiff appressed hairs

Flowers: Flower heads showy, yellow, and radiate, usually in flat-topped panicles of 3-9 flower heads, on peduncles 3-14 cm long; involucres hemispheric, 1-2 cm wide, the bracts (phyllaries) in several series, wider at the base and abruptly narrowed near the tip; rays 10-12 per flower head, the laminae (ray petals) 7-15 mm long, yellow; disc florets 50 or more per flower head, yellow.

Fruits: Achenes 3-4 mm long, covered with stiff hairs; topped with a pappus of 2 slender awns, 3-4 mm long, and 2-4 tiny, irregularly toothed scales, less than 1 mm long.

Ecology: Found on dry slopes, in canyons, and in disturbed areas, below 7,500 ft (2286 m); flowers June-October.

Distribution: AZ, NM, s TX; south through MEX to C. Amer., Cuba

Notes: Distinguished by being a tall perennial, with few to many erect stems from the base, each one often a meter tall; dark green, triangular or lanceolate opposite leaves that are rough-hairy to the touch and often have serrate-toothed margins. The heads are showy, with yellow rays and discs. The seeds are covered with hairs and have a pappus of 2 awns, 1-2 mm long, attached to the top. Similar to V. cordifolia but that species has petioles less than 1 cm long. Also somewhat similar to Heliomeris multiflora (the two species were formerly treated in the same genus), but that species has reliably narrower, lanceolate or linear leaves, and the seeds are not hairy and have no pappus. Also somewhat resembles Verbesina encelioides but that species is annual, with leaf undersides that are quite noticably hairy and gray-green. The name Viguiera dentata var. lancifolia has been used for narrow leaved individuals from Mexico and close to the border in the US.

Ethnobotany: Infusions of the above-ground plant parts are commonly used in Mexico to treat baby rash; research has shown that the plant's essential oils have antibiotic properties.

Etymology: Viguiera named after Louis Guillaume Alexandre Viguier (1790-1867) a French botanist and medical doctor; dentata means toothed like a saw, referring to the leaves.

Synonyms: Encelia montana , Helianthella latifolia , Helianthus dentatus, Viguiera laxa , Viguiera oppositipes , Viguiera pedunculata , Viguiera texana , Viguiera triquetra

Editor: SBuckley 2010, FSCoburn 2015, AHazelton 2017

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E. Makings  
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