The following Participating Institutions are custodians for this species in the CPC National Collection:
Chicago Botanical Garden
The conservation of Agalinis skinneriana is fully sponsored.
Andrea Tietmeyer contributed to this Plant Profile.
This rare annual forb is a hemiparasite, meaning that it attains some of its nutrients by attaching its roots to those of other nearby species. Agalinis skinneriana generally occurs in small scattered populations throughout its range, which extends south from Ontario and Ohio to Missouri and Louisiana. It can be found in a number of different habitats, from sand to mesic prairies, and from rocky open glades to moist thickets. While it appears that this species has always been rare throughout its range, the number of populations appears to have declined since the 1800's (Kercher & Sytsma 2000). It is currently not federally protected, but is listed as threatened or endangered in 5 of the 12 states where it is currently found. A major threat to this species is loss of habitat, both from habitat destruction for development and from habitat degradation due to invasive species and fire suppression.
Research and Management Summary:
A number of studies have recently been performed on this species, as well as on other closely related species in the genus Agalinis. Management for this species, however, is lacking throughout most of its range.
Agalinis skinneriana ranges in height from 10 to 65 cm (3.9 inches to 2.1 feet). On its slender, pale green stems are small, oppositely arranged leaves. Pale pink flowers form on a raceme with corollas that measure 1.0 - 1.5 cm in diameter. Flowering occurs at different times throughout this plant's range, but is generally from August to September.
Distribution & Occurrence
In general, Agalinis skinneriana is described as a species found in the prairie. However, because it has a large geographical distribution, it can be found in a wide range of habitats, including but not limited to: dry to mesic prairies, open woods in shallow rocky soils, bluffs, barrens, pockets among dunes, sandy woods, and moist thickets. (Canne-Hilliker 1987, Trick 1995).
Plants that are often associated with this species include Agalinis purpurea, Aletris farinosa, Andropogon gerardii, Aster ptarmicoides, Calopogon tuberosus, Liatris spicata, Lobelia kalmii, Pycnanthemum virginianum, and Solidago ohioensis (Swink & Wilhelm 1994).
|Currently, this species is found in:
7 Illinois counties (Robertson and Phillipe 1993)
26 Arkansas counties (Smith 1988)
7 sites in Indiana (Hedge et al. 1992)
3 sites in Kansas (Kansas Biological Survey 1994)
2-5 sites in Kentucky, 6 counties in Louisiana, & 1-2 sites in Tennessee (Ostlie 1990)
1 site in Maryland , 1-4 sites in Michigan, 24 locations in Missouri, & 5 sites in Wisconsin (Trick 1995)
3 populations in Ohio (Cusick 1993)
13 sites in southwestern Ontario (Canne-Hilliker 1987)
Trick (1995) reports that populations of Agalinis skinneriana are either in jeopardy, declining, or their status is unknown in every state where the plant is found except Arkansas, where the populations are apparently stable and not currently a concern.
Conservation, Ecology & Research
Visiting insects include bumblebees (Bombus pennsylvanicus, Bombus impatiens), solitary bees (Hymenoptera sp.) (Dieringer 1999), sulphur butterflies (Colias eurytheme) and honeybees (Apis sp.) (Trick 1995).
All species of Agalinis appear to be hemiparasites, meaning that their leaves perform photosynthesis while their roots form parasitic attachments to the roots of nearby species. Studies of Agalinis purpurea, a common associate and close relative of Agalinis skinneriana, have revealed no host specificity for these parasitic connections. (Trick 1995, Baird & Riopel 1984, Riopel & Musselman 1979).
Encroachment of woody vegetation on prairie habitats due to fire suppression
Habitat conversion for agriculture and urban development
Inappropriately timed mowing
Trampling and agricultural activity
Hannelore Artiomow, a graduate student at the University of Wisconsin-Milwaukee, is studying the influence of population size and plant density on pollinator visitation in this species (advisor Jeff Karron) (Artiomow ongoing 2002).
Dieringer (1999) studied the reproductive biology of A. skinneriana in two different populations (one with over 1000 individual plants and another with only a few hundred individual plants) in Illinois. He found that not only is this species capable of self-pollination, but that the rate of self-pollination among plants was higher in the small population than the large.
Judith Canne-Hilliker, at the University of Guelph, Ontario, Canada, has extensively studied the genus Agalinis, including the taxon A. skinneriana. Her studies include work on the chromosome numbers and taxonomy of Agalinis in North America, including A. skinneriana (haploid number n=13) (Canne 1983a).
Most known populations of A. skinneriana are located on private land, and so in many cases they are not monitored, managed for, or protected. (Trick 1995)
Loss of genetic diversity and potential levels of inbreeding depression need to be further investigated.
Seed banking and seedling recruitment are also areas of research that need attention.
A comprehensive plan to protect populations of this species throughout its range is necessary to protect any genetic variation that remains in the species.
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Lovell, J.H. 1918. The Flower and the Bee: Plant Life and Pollination. New York: Charles Scribner's Sons. 286p.
Mohlenbrock, R.H. 1986. Guide to the Vascular Flora of Illinois. Carbondale, Illinois: Southern Illinois University Press. 507p.
Rock, J.F. 1919. A monographic study of the Hawaiian species of the tribe Lobelioideae, family Campanulaceae. Mem. Bernice P. Bishop Mus. 7, 2: 1-395.
Smith, E.B. 1988. An Atlas and Annotated List of the Vascular Plants of Arkansas. Fayetteville: University of Arkansas. 489p.