Flowers are blue, purple, lavender, white, or rose, often with shades of one color present in an individual population.

Flowers have 4 sepals, colloquially denominated "petals", a salverform corolla with 4 lobes, and an inferior ovary.

The fruit is an often roughly cordate capsule enclosing many seeds and which usually dehisces via a suture across its apex.

[4] Its members superficially resembles species of the genus Myosotis (Forget-me-nots), but are distinguished from the latter by having only 4 sepals (petals) instead of 5.

Species accepted as of May 2014 are:[5] Media related to Houstonia at Wikimedia Commons