Houstonia rubra, the red bluet, is a plant species in the Rubiaceae. It is a small herb with red to reddish-purple flowers, native to the southwestern United States and northern and central Mexico.
An ideal soil would be made up of 45% minerals (sand, clay, silt), 5 % organic (plant and animal) material, 25% air and 25% water. The mineral portion would be loam (20 – 30% clay, 30 – 50% silt and 30 – 50% sand).
