Ruellia humilis cladeErin Tripp
- Ruellia caroliniensis (Walt.) Steud.
- Ruellia humilis Nutt.
- Ruellia purshiana Fernald
- Ruellia strepens L.
Note: this taxon list is still under construction. It does not yet contain all known Ruellia humilis clade subgroups.
Only species that were sampled in Tripp's study (in press) are listed.
The Ruellia humilis clade is has been resolved as sister to Euruellia, but this relationships is still tentative and thus is not depicted on the Ruellia s.l. tree. Species in this group differ from those in Euruellia by having reduced inflorescences with subsessile flowers in axillary cymes. They also have slightly clavate capsules (vs. elliptical in Euruellia) that contain fewer ovules. Plants in the R. humilis clade are distributed in the eastern United States, reaching their northernmost limits in Pennsylvania and Wisconsin. The latter state represents the northernmost distribution of the genus in the western hemisphere, and perhaps the northernmost globally.
Most if not all species in this clade produce cleistogamous (see photo above) in addition to open flowers, either after the regular flowering season, or concurrently. Species sampled in Tripp's study (in press) are listed above, though the group likely includes other species such as Ruellia ciliosa Pursh, and the white-flowered, night blooming Ruellia noctiflora (Nees) A. Gray.
Fernald, M. L. 1945. Ruellia in the eastern United States. Rhodora 47: 1-38, 47-63, 69-90.
Long, R. W. 1970. The genera of Acanthaceae in the southeastern United States. J. Arnold Arboretum 51: 257-309.
Tripp, E. A. Evolutionary relationships within the species-rich genus Ruellia (Acanthaceae). Systematic Botany, in press.
Tripp, E. A. 2004. The current status of two rare species of Ruellia (Acanthaceae) in Pennsylvania. Bartonia 62: 55-62.
Wasshausen, D. C. 1998. Acanthaceae of the southeastern United States. Castanea 63: 99-116.
Correspondence regarding this page should be directed to Erin Tripp at
Page copyright © 2007
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- First online 10 April 2007
- Content changed 10 April 2007
Citing this page:
Tripp, Erin. 2007. Ruellia humilis clade. Version 10 April 2007 (under construction). http://tolweb.org/Ruellia_humilis_clade/103638/2007.04.10 in The Tree of Life Web Project, http://tolweb.org/