In the classification of order there seems to be discrepancies in taxonomic opinion. Brummitt's compilation alone includes eight systems of classification.
In the four o'clock family, Nyctaginaceae, there are 38 genera that thrive in the tropics and subtropics as trees, and herbs. The flowers of the members of this family lack petals, but have a brightly colored calyx which is often mistaken for a corolla. The leaves are paired, and the fruit is a nutlike achene. Several of the well known relatives of Abronia are Bougainvillea and Mirabilis.
Abronia macrocarpa
Flower:
inflorescence 4-7 cm across with 20-75 flowers 18-32
mm long magenta to purple tubes no petals, but a brightly colored calyx
Stems: horizontal trailing up to 20 inches; sticky hairs which trap the sand
Seed structure:
8-15 mm long by 7-12 mm wide achene with five prominent,
often twisted, wings; one
cotyledon is abortive leaving a single cotyledon
Root: somewhat woody taproot which allows the plant to survive the summer
Leaves: ovate with entire margin, placement is opposite with a disparity in size
Growing season:
perennial; active April through September; blooming March through June
in late afternoon
Abronia spp. are usually located in sandy well
drained soils. Abronia macrocarpa is found in post oak woods where there
is yaupon (Ilex vomitoria) and grape plants which feed its pollinator
moth larvae. This sand verbena grows in deep sandy soils in disturbed areas.
Threats to the large-fruited sand verbena include human development, fire
suppression, off-road vehicles, picking wildflowers, and encroachment of
grasses (e.g. lovegrass - Eragrostis). Currently three populations
exist with a total of 3000 plants.
| The red area indicates the extent of the post oak savannah
were Abronia macrocarpa is found. Abronia macrocarpa however
has only been found in Leon, Robertson, and Freestone counties in Texas.For
more information on this vegetative zone please check this ecological
summary.
|
Abronia macrocarpa was discovered in 1968, then federally listed as endangered on September 28,1988. This member of the four o'clock family is listed on both the federal and Texas state endangered lists and has a recovery plan. The endangered classification indicates that the taxa may not continue to exist if the causes of its elimination are not corrected; the group is in immediate danger of extinction. The global rank of G1 is giving this species. A G1 rating indicates there are 1-5 sites or less than 1,000 individuals known.
The Abronia spp. historically have been used by the Native Americans for both food and medicinal purposes. Roots and leaves were used to treat boils and abscesses, bites from beetles, and the swallowing of a spider. The starchy roots were mixed in with cornmeal. The Texas species however do not appear to have the same flavor as other species in the United States. The aromatic flowers have also been used in making scented oils. Wool dyes and ornamental landscaping have also been uses of the sand verbenas.
Cheatham, Scooter, Marshall C. Johnston, with Lynn Marshall. The Useful Wild Plants of Texas, the Southeastern and Southwestern United States, the Southern Plains, and Northern Mexico. Vol 1; pp1-7. Useful Wild Plants Inc: Austin. 1995
http://www.mobot.org/CPC/abronia.html
IUCN Red Data Book Categories http://www.wcmc.org.uk/species/plants/categories.html
Plant Families of Southern California http://eco.bio.lmu.edu/www_nat_history/plants/fams/nyct.htm
Rickett, Harold William. Wild Flowers of the United States: Volume 3: Texas. Vol 1 of 2; pp81,84. McGraw-Hill Book Company: New York. 1969.
Texas Parks & Wildlife http://www.tpwd.state.tx.us/nature/endang/sandverb.htm
U.S. Fish and Wildlife Service Division of Endangered Species http://www.fws.gov/r9endspp/plants1.html#Lnk55
Vascular Plant Families and Genera. Compiled by RK Brummitt. p625. Royal Botanic Gardens: KEW 1992.
Images modified from:
TAMU-BWG Digital Library http://www.csdl.tamu.edu/FLORA/cgi/gallery_query?q=abronia+macrocarpa
Checklist of the Vascular Plants of Texas http://www.csdl.tamu.edu/FLORA/tracy/taesreg3.htm