font settings

Font Size: Large | Normal | Small
Font Face: Verdana | Geneva | Georgia

Acourtia

(Genus)

Overview

[ Back to top ]

Perennials, (2.5-) 5-50(-150+) cm (caudices brown-woolly, aerial stems glabrate or resinous-punctate). Leaves basal, cauline, or both; shortly petiolate or sessile; blades elliptic-oblong, lanceolate, oblong, oblong-lanceolate, oblong-oblanceolate, orbiculate, ovate, ovate-ellipti c, or rhombic-orbiculate (thin and chartaceous to thick and coriaceous), bases cuneate to cordate or clasping, margins entire or lobed or pinnately parted, dentate, or serrate, faces usually minutely stipitate-glandular and/or hirtellous. Heads quasi-radiate [discoid] (see florets), borne singly or in paniculiform or corymbiform arrays. Involucres turbinate or obconic to campanulate, 6-17+ mm. Phyllaries in 1-7 seri es, lanceolate to oblanceolate or linear, unequal (rigid, margins scarious), apices obtuse to acute, acuminate, or mucronate. Receptacles concave, flat, or convex, usually foveolate, alveolate, or reticulate, pubescent, sometimes paleate (paleae apically pubescent). Florets 3-25(-80), bisexual, fertile; corollas pink to lavender or white [yellow], zygomorphic (2-lipped; outer lip liguliform, 3-toothed, inner usually smaller, 2-lobed, < span class="toolTipElement" title="Lobes ::(Gr. lobos: lobe) Any segment of an organ, as of a leaf, especially if rounded.">lobes often curled) ; anther basal appendages entire, elongate, rounded, apical appendages lanceolate; style branches relatively short, apices blunt-penicillate (abaxial faces usually glabrous, i.e., without collecting hairs). Cypselae ± fusiform or terete to cylindric, 4-10 mm, not beaked, usually ± ribbed, faces glabrous or stipitate-glandular; pappi of 40-60(-80+) ta n or white, ± barbellate to nearly smooth bristles in 1-3(-9) series. x = 27.

Species ca. 41: warm regions of North America, Mexico, Central America.

Acourtia consists of two clades, one with species that have scapiform stems and the other with species that have leafy flowering stems. From about 1873 to 1973, Acourtia species were treated as members of Perezia, usually as Perezia sect. Acourtia (D. Don) A. Gray. J. L. Reveal and R. M. King (1973) reestablished Acourtia for the leafy-stemmed North American species, and B. L. Turner (1978) added the scapiform species. Molecular evidence (H. G. Kim et al. 2002) indicated Acourtia is most closely related to Proustia and Trixis and not to Perezia.[1]

Photos

[ Back to top ]

Taxonomy

[ Back to top ]

The Genus Acourtia is further organized into finer groupings including:

Bibliography

[ Back to top ]

Footnotes

[ Back to top ]
  1. Beryl B. Simpson "Acourtia". in Flora of North America Vol. 19, 20 and 21 Page 12, 14, 57, 70, 71, 72, 73. Oxford University Press. Online at EFloras.org.

Sources

[ Back to top ]
Last Revised: January 24, 2010
2010/01/24 05:28:52